Commit Graph

1482218 Commits

Author SHA1 Message Date
Sun Jian
115bf3e515
exec: Drop bprm loader before closing bprm->file
free_bprm() currently drops what may be the final reference to
bprm->file before calling bprm_drop_loader(). Since
bprm_drop_loader() is attachable via BPF fentry and bprm->file is
exposed as a BTF_TYPE_SAFE_TRUSTED pointer, the file can be observed
after its reference has been released.

Move bprm_drop_loader() before do_close_execat(bprm->file), keeping
the file reference held while the hook runs. This preserves the
existing trusted BTF contract without changing verifier behavior.

The loader file and bprm->file have independent references, so this
reordering does not change their required teardown ordering.

Link: https://sashiko.dev/#/patchset/20260831092305.42062-1-tasos.papagiannnis@gmail.com?part=3
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://patch.msgid.link/20260901114011.112375-1-sun.jian.kdev@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-03 09:23:44 +02:00
Melissa Wen
88f8113ab1 drm/amd/display: use plane color_mgmt_changed to track colorop changes
This is a resubmission of commit d79716401a ("drm/amd/display: use
plane color_mgmt_changed to track colorop changes") whose change was
reverted by commit 0461ba9a79 ("Merge tag 'amd-drm-next-7.3-2026-07-02'
of https://gitlab.freedesktop.org/agd5f/linux into drm-next") during a
merge conflict resolution.

Original commit message:

```
Ensure the driver tracks changes in any colorop property of a plane
color pipeline by using the same mechanism of CRTC color management and
update plane color blocks when any colorop property changes. It fixes an
issue observed on gamescope settings for night mode which is done via
shaper/3D-LUT updates.
```

Fixes: 0461ba9a79 ("Merge tag 'amd-drm-next-7.3-2026-07-02' of https://gitlab.freedesktop.org/agd5f/linux into drm-next")
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Link: https://patch.msgid.link/20260807115712.22423-1-mwen@igalia.com
2026-09-03 04:11:28 -03:00
Jakub Kicinski
2f38e26a57 Merge branch 'net-rds-own-the-fastpath-locks-across-connection-teardown'
Allison Henderson says:

====================
net/rds: own the fastpath locks across connection teardown

This is v5 of the follow-up set to "net/rds: Bug fix ports, part 2"
[1] (v1 at [2], v2 at [3], v3 at [4], v4 at [5]).  During review of part 2,
the later half of that series needed more work than a respin, so it was
split off into this set together with the companion fixes identified
along the way.  As discussed on the v2 thread, it is targeted at net.

RDS connection teardown quiesces the transmit and receive-refill fast
paths by waiting for the RDS_IN_XMIT/RDS_RECV_REFILL bits to be
sampled clear.  Sampling a bit clear is not owning it: the fast path
can re-take its bit right after the wait returns and then run
concurrently with the transport shutdown and the send-state reset.
Oracle UEK closed this by making teardown acquire the bits as locks
("rds: Make sure transmit path and connection tear-down does not run
concurrently"); patches 5 and 6 do the same for the two
rds_send_path_reset() call sites upstream.

Making teardown block on the bits as locks promotes several latent
ordering bugs from rare to load-bearing, so they are fixed first:

  Patches 1 and 2 fix the release side of the two bit locks.
  release_in_xmit() and release_refill() both clear their bit and then
  test for waiters, but the barrier is on the wrong side of the clear
  to order the critical section's stores before the release, and the
  waiter check does not order against the clear.  Once teardown blocks
  on these bits as locks (uninterruptible and untimed), a lost wake-up
  or a store observed out of order stops mattering only in theory.
  Use clear_bit_unlock() and wq_has_sleeper(), the pattern already
  half-present in release_in_xmit().

  Patch 3: rds_conn_path_reset() wipes the whole cp_flags word with a
  plain store.  Once teardown owns bits in that word across the reset,
  a blanket store would end lock ownership early - and it already
  races atomic RMWs on the same word today.  Clear the bits the reset
  is responsible for individually, as Oracle UEK also does.

  Patch 4: rds_tcp_reset_callbacks() stores RDS_CONN_RESETTING
  unconditionally, which can overwrite the RDS_CONN_ERROR or
  RDS_CONN_DISCONNECTING of a shutdown already in progress on the same
  path and send that shutdown through an extra drop cycle.  Once the
  accept path can park for the duration of a teardown (patch 6) that
  window widens, so make the transition conditional first, as Oracle
  UEK does.

With those in place, patch 5 converts rds_tcp_reset_callbacks() from
waiting on RDS_IN_XMIT to acquiring it, holding it across the socket
swap and rds_send_path_reset(), and patch 6 has rds_conn_shutdown()
hold both bit locks across the transport shutdown and path reset.

Patch 7 fixes a pre-existing teardown-state hole that this series
makes easier to hit but did not introduce.  Since commit
e97656d03c the final transition in rds_conn_shutdown() accepts
RDS_CONN_ERROR as well as RDS_CONN_DISCONNECTING, so that a FIN
processed during the teardown does not derail the shutdown.  But
consuming that RDS_CONN_ERROR also consumes the shutdown pass that a
concurrent rds_conn_path_drop() queued along with it.  For a FIN that
is harmless; for rds_tcp_accept_one() it is not.  A drop can race the
accept's DOWN -> CONNECTING path claim, the accept then installs the
freshly accepted socket while the drop's teardown - which sampled
tc->t_sock before that socket existed - is still running,
rds_connect_path_complete() fails and drops the path again, and if the
in-flight shutdown's final transition then swallows that
RDS_CONN_ERROR, the pass that should reap the just-installed socket
finds the path already RDS_CONN_DOWN and does nothing.  The socket is
leaked with its callbacks armed and its rds_tcp_connection still on
rds_tcp_tc_list, the peer sees an established connection that nothing
reads, and the path wedges in RDS_CONN_DOWN.  Make the final
transition DISCONNECTING -> DOWN only and leave a racing drop's
RDS_CONN_ERROR alone, so the pass it queued runs and tears down
whatever attached to the path; the branch quiesces the reconnect
timer itself, since a pending destroy can suppress that pass (see the
changes below).

This surfaced while re-reviewing v3: whether the
release-then-transition ordering in patch 6 could let a woken waiter
install a socket that the teardown then strands.  Chasing that down,
the reachable form of the leak turned out to be the accept-vs-drop
race above rather than the parked-waiter path (a path mid-teardown is
never handed to rds_tcp_reset_callbacks(): rds_tcp_accept_one_path()
only claims a path it can move DOWN -> CONNECTING), and it predates
this series.  It reproduces on an instrumented kernel - a test-only
drop injected into the accept window plus a widened teardown-to-tail
window - as an ESTABLISHED socket with an ever-growing receive queue
on a path stuck down; the same kernel runs clean with patch 7.

The set was built per-commit, run through the rds selftests (tcp and
rdma/rxe), and exercised with a connection/netns churn load and
module load/unload cycles; the patch 7 destroy-window fix was
additionally verified against an instrumented kernel that reproduces
the timer-left-armed WARN deterministically (fires on every destroyed
path unfixed, silent with the fix).
====================

Link: https://patch.msgid.link/20260828223921.202913-1-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:26 -07:00
Allison Henderson
260c6308fe net/rds: don't let rds_conn_shutdown() consume a concurrent drop
rds_conn_shutdown() finishes by moving the path from
RDS_CONN_DISCONNECTING to RDS_CONN_DOWN, and also accepts
RDS_CONN_ERROR as the starting state of that final transition, so that
a FIN processed in softirq context during the teardown does not derail
the shutdown into a noisy error path.

But consuming that RDS_CONN_ERROR also consumes the shutdown pass that
came with it: rds_conn_path_drop() sets RDS_CONN_ERROR and then queues
cp_down_w, and a pass that starts on a path already in RDS_CONN_DOWN
is a no-op.  For the FIN case that is harmless - the socket the FIN
arrived on is the very socket the teardown just released.  It is not
harmless for a dropper that attached something to the path first.

rds_tcp_accept_one() is such a dropper.  Its path claim in
rds_tcp_accept_one_path() transitions RDS_CONN_DOWN ->
RDS_CONN_CONNECTING, and a concurrent drop - a FIN on a previous
socket in softirq context, an administrative reset - can put the path
into RDS_CONN_ERROR between that claim and the state check that
follows, which accepts RDS_CONN_ERROR.  The accept then installs the
freshly accepted socket with rds_tcp_set_callbacks() while the queued
teardown - which sampled tc->t_sock before this socket existed - is
still running.  rds_connect_path_complete() fails its transition to
RDS_CONN_UP and drops the path again, queueing the pass that should
reap the socket it just installed.  If the in-flight shutdown's final
transition consumes that drop's RDS_CONN_ERROR, the queued pass finds
the path in RDS_CONN_DOWN and does nothing.  The installed socket is
never torn down: it sits established with its callbacks armed and its
rds_tcp_connection on rds_tcp_tc_list, the peer sees a connection that
nothing ever reads, and the path is wedged in RDS_CONN_DOWN until some
later event drops it again.  Reproduced with widened race windows as
an ever-growing receive queue on a socket owned by a path stuck in
RDS_CONN_DOWN, with the peer's send path wedged behind it.

Make the final transition only DISCONNECTING -> DOWN.  If it fails
because the path is in RDS_CONN_ERROR, a drop raced the teardown:
cancel the reconnect timer and clear RDS_RECONNECT_PENDING - the one
piece of the skipped tail that must not be left behind - and return,
letting the pass the drop queued finish the job: it tears down
whatever attached to the path in the meantime, completes the
transition to RDS_CONN_DOWN, and re-arms the reconnect from its own
tail.

The timer quiesce in that branch matters because the racing drop does
not always queue that pass: rds_conn_path_drop() returns without
queueing when a destroy is pending - exactly the situation during a
netns teardown or module unload, when a FIN on the dying socket is
processed while rds_conn_path_destroy() flushes cp_down_w.  If the
flushed pass is the one that takes this return, no later pass exists,
and rds_conn_path_destroy() would find cp_conn_w still armed
(WARN_ON) and then free a path whose reconnect timer can still fire.
With the cancel in the branch, every exit of a shutdown pass leaves
the timer quiesced no matter which pass completes the transition.

The FIN case keeps making progress, one pass later and still without
noisy logging.  Any other state keeps today's rds_conn_path_error()
handling; no current cp_state writer can leave a DISCONNECTING path
in anything but RDS_CONN_ERROR (every other writer is a cmpxchg from
a non-DISCONNECTING state), so that branch is defensive.

On kernels without the preceding patches the same hazard exists with
the sample-based quiesce; the fix applies there equally.

Fixes: e97656d03c ("rds: tcp: allow progress of rds_conn_shutdown if the rds_connection is marked ERROR by an intervening FIN")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-8-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:24 -07:00
Håkon Bugge
813f3582ac net/rds: acquire the fastpath locks in rds_conn_shutdown()
rds_conn_shutdown() quiesces the transmit and receive-refill paths by
waiting for RDS_IN_XMIT and RDS_RECV_REFILL to be sampled clear, and
then runs the transport shutdown and rds_conn_path_reset().  Sampling
the bits clear is not the same as owning them: the moment after the
wait_event() returns, rds_send_xmit() can re-acquire RDS_IN_XMIT (or
rds_ib_recv_refill() can re-acquire RDS_RECV_REFILL) and run
concurrently with the teardown.

The sender does recheck the connection state after taking the lock,
but that recheck is a classic store-buffering pattern: teardown writes
the state and reads the bit while the sender writes the bit and reads
the state.  acquire_in_xmit() is only an acquire operation, so on
weakly ordered architectures both sides can miss each other's write,
and the transmit path then runs while the transport zeroes its rings
(e.g. rds_ib_ring_init()) and rds_send_path_reset() rewrites the
transmit state under it.

Oracle UEK fixed the same class of crashes - a 14-year tail of
BUG_ON()s in rds_ib_sub_signaled(), unexpected op-codes and NULL
dereferences in rds_ib_send_cqe_handler() during failover testing -
by making the teardown path *acquire* the fastpath bit locks instead
of testing them ("rds: Make sure transmit path and connection
tear-down does not run concurrently").  Ownership of a single word is
decided by RMW atomicity, so no cross-variable ordering is needed.

Do the same here: take both locks before calling the transport
shutdown, hold them across rds_conn_path_reset(), and release them
explicitly with a wake-up afterwards.  Both are released with
clear_bit_unlock(), so that the ring re-initialization done by the
transport shutdown and the transmit state rewritten by
rds_send_path_reset() are ordered before either bit is seen clear by
the next acquire_in_xmit() or acquire_refill().

The fastpath users of these bits - rds_send_xmit() and
rds_ib_recv_refill() - are trylock style and back off while teardown
owns the locks, so no new lock dependency is introduced for them.
rds_tcp_reset_callbacks() is different: since the previous patch it
acquires RDS_IN_XMIT as well, and it blocks doing so, so its wait now
spans the teardown instead of at most one send batch.  That waiter
runs from rds_tcp_accept_one() on the single-threaded krdsd workqueue
and holds rds_tcp_accept_lock and t_conn_path_lock while it waits, so
a duelling SYN accepted while its path is being torn down parks
accept processing for the duration of the teardown - for TCP bounded
by the (up to 5 s) drain loop in rds_tcp_conn_path_shutdown().  An IB
path's drain in rds_ib_conn_path_shutdown() has no round cap, but no
blocking waiter either: rds_tcp_reset_callbacks() is the only blocking
acquirer of these bits and waits only on its own TCP path, and the
fastpaths are trylock-and-back-off on both transports, so a long IB
drain lengthens only that path's own quiesce.  The
window is narrow: the accept-side state check has to pass before the
teardown moves the path to RDS_CONN_DISCONNECTING.

Because krdsd is a single global workqueue, everything else queued
there - accept processing for other connections and network
namespaces, and the flush_workqueue(rds_wq) in rds_tcp_listen_stop()
during namespace teardown - waits behind the parked accept worker for
that time.  It cannot deadlock, although the waits do point at each
other: the teardown blocks until the bit's holder releases it, and
the holder may be that krdsd accept worker.  The holder finishes
without needing anything the teardown owns: the sync cancels
rds_tcp_reset_callbacks() issues target cp_send_w and cp_recv_w on
the path's ordered cp_wq, whose only execution slot is occupied by
the blocked cp_down_w itself, so they are pending at most and cancel
without flushing - a reliance on cp_wq being ordered that is now
noted next to those cancels (on the allocation-failure fallback where
a path shares rds_wq, the work items simply serialize).
Nor is the blocking wait itself new: rds_tcp_reset_callbacks() has
waited on RDS_IN_XMIT from the krdsd work item since
commit 335b48d980 ("RDS: TCP: Add/use rds_tcp_reset_callbacks to
reset tcp socket safely"); this patch stretches its worst case from
a sender's batch to the teardown's drain.  The alternative to parking
is the accept path racing the teardown, which is what these patches
close; making the teardown itself non-blocking is a separate item.

One observable side effect: the SENDING flag reported by rds-info has
always mirrored RDS_IN_XMIT, so it now also covers the window where
teardown owns the bit.

The comments that describe the old sample-based handshake or name
rds_send_xmit() as the only other holder of these bits - in
rds_send_xmit(), above rds_conn_path_reset(), in rds_ib_recv_refill()
and in rds_tcp_reset_callbacks() - are updated to match.

For anyone backporting this patch standalone: it depends on
"net/rds: clear cp_flags bits individually in rds_conn_path_reset()"
and "net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()"
earlier in this series.  Without the former, the blanket cp_flags
clear in rds_conn_path_reset() would drop both held bits in the middle
of the teardown; without the latter, rds_tcp_reset_callbacks() would
still sample t_sock without owning RDS_IN_XMIT.  "net/rds: use
clear_bit_unlock() in release_refill()" is needed for the refill
side's release to pair with the acquire added here, and the follow-up
"net/rds: don't let rds_conn_shutdown() consume a concurrent drop"
completes the teardown-state handling for the waiter this patch
parks; a backport should carry all four.

Fixes: 0f4b1c7e89 ("rds: fix rds_send_xmit() serialization")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
[achender: reimplement for net-next shutdown path: acquire the existing
 RDS_IN_XMIT/RDS_RECV_REFILL bit locks in rds_conn_shutdown() and release
 after teardown; update comments and commit message]
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-7-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Allison Henderson
02c5f9dc2e net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()
rds_tcp_reset_callbacks() quiesces the transmit path by setting the
path state to RDS_CONN_RESETTING and then waiting for RDS_IN_XMIT to
be sampled clear before swapping the underlying socket and calling
rds_send_path_reset().

Sampling the bit clear is not the same as owning it: rds_send_xmit()
can re-acquire RDS_IN_XMIT right after the wait_event() returns.  Its
state recheck after taking the lock is a store-buffering pattern (the
resetter writes the state and reads the bit, the sender writes the
bit and reads the state) and acquire_in_xmit() is only an acquire
operation, so on weakly ordered architectures both sides can miss
each other's write and the transmit path then runs concurrently with
rds_send_path_reset() rewriting cp_xmit_* state - which is exactly
what the comment above rds_send_path_reset() tells its callers to
prevent.

Take the lock instead, hold it across the socket swap and
rds_send_path_reset(), and release it with a wake-up at the end.  The
lock-ordering constraint documented above the wait still holds: the
lock is acquired before lock_sock(), so a sender inside tcp_sendmsg()
can never be waited on while we hold the socket lock.

Two details of the old code go away with the same change:

 - t_sock is now read only after the lock is acquired.  The old code
   cached it before waiting; the teardown in rds_conn_shutdown()
   releases that socket and clears t_sock, so a pointer cached before
   the wait can be stale by the time the accept path resumes.  Reading
   it under RDS_IN_XMIT is what makes the exclusion complete once the
   teardown owns the same lock, which the next patch arranges; until
   then the teardown still only samples the bit, and the two paths
   remain as exposed to each other as they are today.

 - The old !osock early path called rds_send_path_reset() with no
   serialization at all.  It now runs under the lock like the normal
   path.  The conditional RDS_CONN_RESETTING transition of the
   previous patch happens before the socket check either way: a path
   found without a socket is either still connecting (its reconnect
   worker blocked on t_conn_path_lock) and legitimately goes
   RESETTING -> UP on the new socket, or it has been torn down
   meanwhile and is dropped.

The in-function comment describing the old wait-based quiesce is
rewritten to describe the lock-based one, and the stale block comment
above the function (which still described a return value and an
incomplete list of t_sock writers) is refreshed to name all four
writers - the connect, accept, teardown and swap paths - and what
serializes each of them.

Fixes: 335b48d980 ("RDS: TCP: Add/use rds_tcp_reset_callbacks to reset tcp socket safely")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-6-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Gerd Rausch
e8e60d74fe net/rds: tcp: don't force RDS_CONN_RESETTING over a concurrent shutdown
rds_tcp_reset_callbacks() resolves a duelling SYN by storing
RDS_CONN_RESETTING into cp_state unconditionally.  Nothing serializes
that store against the shutdown path: rds_tcp_accept_one() checks
for RDS_CONN_CONNECTING or RDS_CONN_ERROR under t_conn_path_lock, but
neither rds_conn_path_drop(), which forces RDS_CONN_ERROR, nor
rds_conn_shutdown(), which moves the path to RDS_CONN_DISCONNECTING
under cp_cm_lock, takes that lock.  The store can therefore land on
top of a shutdown that is already in progress, or that gets queued
right after the accept-side check.

When it does, the shutdown worker's final DISCONNECTING -> DOWN
transition fails and the path goes through rds_conn_path_error() and
a second drop/shutdown cycle instead of a clean reconnect, tearing
down the socket the accept path has just installed.  Before commit
ad22d24be6 ("net/rds: No shortcut out of RDS_CONN_ERROR") a path
found in RDS_CONN_RESETTING even made rds_conn_shutdown() bail out
altogether.

Make the transition conditional: move CONNECTING -> RESETTING (or
stay in RESETTING from an earlier duel), and drop the path in any
other state.  The drop has side effects of its own: it replaces the
shutdown's RDS_CONN_DISCONNECTING (or RDS_CONN_ERROR) with
RDS_CONN_ERROR and queues one more cp_down_w run.  The difference is
that rds_conn_shutdown() accepts RDS_CONN_ERROR in its final
transition to RDS_CONN_DOWN, so the shutdown in flight completes
normally instead of through rds_conn_path_error(); the extra
down-work pass then finds the path already down and falls through to
the reconnect check, or catches a reconnect that has already started
and restarts it.  The accept path still installs the new socket,
rds_connect_path_complete() then fails its RESETTING -> UP transition
and drops it: the raced socket ends up torn down as it does today.
The comment at that call site, which promised that
rds_connect_path_complete() marks the path RDS_CONN_UP, is updated to
name this outcome as well.

The state can change again between the failed transitions and the
drop.  That is inherent to rds_conn_path_drop(), which the socket
state-change callbacks also call unconditionally, and costs at most
one extra drop/reconnect cycle.

Based on Oracle UEK commit "net/rds: Don't force state
RDS_CONN_RESETTING" by Gerd Rausch.

Fixes: 9c79440e2c ("RDS: TCP: fix race windows in send-path quiescence by rds_tcp_accept_one()")
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
[achender: port to net-next: use the two-argument
 rds_conn_path_transition()/rds_conn_path_drop() and rewrite the
 changelog for the upstream shutdown path]
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-5-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Allison Henderson
103c4b13c4 net/rds: clear cp_flags bits individually in rds_conn_path_reset()
rds_conn_path_reset() wipes the whole flag word with a plain
cp->cp_flags = 0 store.  Every other accessor of that word uses
atomic bitops, and some of them can run concurrently with the reset:
RDS_LL_SEND_FULL is set from rds_send_xmit() and cleared from the
transport completion paths, neither of which holds anything that
excludes the shutdown worker.  A plain store racing an atomic
read-modify-write on the same word is a data race, and whichever
side loses has its update silently discarded.

Clear the two bits the reset is actually responsible for instead.
RDS_IN_XMIT and RDS_RECV_REFILL need no store at all here: they
belong to the caller, rds_conn_shutdown(), which waits for both to be
clear before calling the transport shutdown and this reset.

This also gives every bit in cp_flags a single well-defined writer
discipline, which the following patches rely on when they turn
RDS_IN_XMIT and RDS_RECV_REFILL into bit locks held across the
teardown: a blanket store mid-teardown would destroy lock ownership
that an atomic clear preserves.

Oracle UEK carries the same conversion ("net/rds: Preserve essential
connection state flags"), motivated by its asynchronous shutdown
state machine, whose progress and destroy flags must survive the
reset.  UEK's variant also clears RDS_IN_XMIT and RDS_RECV_REFILL
because there the reset runs as the final step of a teardown that
owns both bits, making those clears its unlock.  Upstream that
release belongs in rds_conn_shutdown(): once a later patch in this
series turns the two bits into locks held across the teardown, ending
ownership needs release semantics and a wake-up that a plain clear
inside the reset would not provide.

Based on Oracle UEK commit "net/rds: Preserve essential connection
state flags" by Gerd Rausch.

Fixes: 00e0f34c61 ("RDS: Connection handling")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-4-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Allison Henderson
17c4476dbb net/rds: use clear_bit_unlock() in release_refill()
release_refill() drops the RDS_RECV_REFILL bit with a plain
clear_bit().  clear_bit() has no ordering semantics, and the
smp_mb__after_atomic() that follows it sits on the wrong side for a
lock release: it orders the clear against the waitqueue_active() load
below it, but does nothing to order the refill critical section's ring
and descriptor stores before the clear itself.

That matters once connection teardown owns RDS_RECV_REFILL as a lock
across the transport shutdown and path reset, rather than sampling it
clear, which "net/rds: acquire the fastpath locks in
rds_conn_shutdown()" later in this series arranges: on a weakly
ordered architecture the teardown can win the bit and start the
shutdown and reset while some of the refill's stores are not yet
visible to it.  The same gap existed under the sample-based scheme - a
waiter that saw the bit clear had no guarantee it also observed the
refill's stores - but taking the bit as a lock makes the missing
release pairing load-bearing.

Switch to clear_bit_unlock(), which orders the critical section before
the release, and replace the open-coded barrier-plus-waitqueue_active()
with wq_has_sleeper(), whose internal full barrier keeps the
store-buffering guarantee between clearing the bit and checking for
sleepers.  This mirrors what "net/rds: use wq_has_sleeper() in
release_in_xmit()" does for RDS_IN_XMIT.

The fast-path acquire side, acquire_refill(), uses test_and_set_bit(),
a full-barrier RMW that pairs with this release.  The teardown at this
point in the series still samples the bit, so on its own this change
is release-side hardening; the shutdown-conversion patch named above
makes the teardown acquire the bit with the same RMW, completing the
pairing at the end of the series.

Fixes: 73ce4317bf ("RDS: make sure we post recv buffers")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-3-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Allison Henderson
6d0c8b7073 net/rds: use wq_has_sleeper() in release_in_xmit()
release_in_xmit() clears RDS_IN_XMIT with clear_bit_unlock() and then
checks waitqueue_active() to decide whether anyone needs waking.
clear_bit_unlock() is only a release operation: it orders the
critical section before the bit clear, but does not order the
subsequent plain load of the wait queue head after it.  The waiter
side does the mirror image - it adds itself to the wait queue and
then tests the bit.  That is the classic store-buffering pattern: the
releasing CPU can read the wait queue as empty while the waiting CPU
still reads the bit as set, so the sleeper is never woken.

The waiters are rds_conn_shutdown() and rds_tcp_reset_callbacks(),
both in uninterruptible wait_event() with no timeout.  A lost wake-up
strands the shutdown worker on its single-threaded workqueue until
some other sender releases the bit again - and on a connection that
is being torn down precisely because it failed, there may never be
another sender.

The barrier used to be there: release_in_xmit() did clear_bit()
followed by smp_mb__after_atomic() until commit 1422f28826 ("rds:
introduce acquire/release ordering in acquire/release_in_xmit()")
folded both into clear_bit_unlock(), which strengthened the lock
hand-off but silently dropped the full barrier the wake-up check
depends on.  The refill counterpart, release_refill() in
net/rds/ib_recv.c, still carries its smp_mb__after_atomic() for
exactly this reason.

Use wq_has_sleeper(), which is waitqueue_active() preceded by the
required full barrier.

Fixes: 1422f28826 ("rds: introduce acquire/release ordering in acquire/release_in_xmit()")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-2-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:42:23 -07:00
Ian Lin
08710f033e net: usb: qmi_wwan: add Compal EXM-G1x support
The Compal EXM-G1x is a Qualcomm SDX12-based LTE modem. Add support for
its QMI WWAN interface 8 using the DTR quirk.

Tested on a Compal EXM-G1x modem.

Signed-off-by: Ian Lin <jisayme@gmail.com>
Link: https://patch.msgid.link/20260831084124.65074-1-jisayme@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:24:38 -07:00
Nicolai Buchwitz
d85f521a9a net: macb: exclude software FCS from TX byte statistics
Frames for which macb_pad_and_fcs() supplies the FCS have four FCS
bytes appended, and TX completion then accounts the grown skb->len.
tx_bytes is defined to exclude the FCS, so these frames are reported
four bytes too large.

Track only the number of FCS bytes appended in software, 0 or
ETH_FCS_LEN, and subtract that from skb->len at completion. skb->len
already reflects the padded length by then, so there is nothing else
to store. macb_pad_and_fcs() already returns 0 on every non-error
path. Return the FCS length from there instead, rather than
recomputing the same check in the caller. BQL stays on the padded
skb->len that netdev_tx_sent_queue() saw.

Fixes: 653e92a917 ("net: macb: add support for padding and fcs computation")
Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
Link: https://patch.msgid.link/20260831113128.1678674-1-nb@tipi-net.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 19:22:53 -07:00
Kuniyuki Iwashima
debac3a20d net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().
syzbot reported the warning in cfg80211_pernet_exit(). [0]

The repro does the following:

  1. create two device in root netns and non-root netns
  2. assign the same altname for the two devices
  3. remove the non-root netns

Since commit 7663d52209 ("net: check for altname conflicts
when changing netdev's netns"), cfg80211_switch_netns() and
cfg802154_switch_netns() fail if init_net has a device with the
conflicting altname.

default_device_exit_net() had the same issue and commit d09486a04f
("net: fix removing a namespace with conflicting altnames") fixed it.

cfg80211_pernet_exit() and cfg802154_pernet_exit() need the same fix.

Let's generalise the fix by removing conflicting altnames for dying
netns in __dev_change_net_namespace().

[0]:
cfg80211_switch_netns(rdev, &init_net)
WARNING: net/wireless/core.c:1871 at cfg80211_pernet_exit+0xd5/0x120 net/wireless/core.c:1871, CPU#1: kworker/u8:9/1160
Modules linked in:
CPU: 1 UID: 0 PID: 1160 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:cfg80211_pernet_exit+0xd5/0x120 net/wireless/core.c:1871
Code: e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 b4 ef 0e f7 4d 8b 36 49 81 fe 20 10 4a 90 74 12 e8 03 3d 9f f6 eb 85 e8 fc 3c 9f f6 90 <0f> 0b 90 eb cc e8 f1 3c 9f f6 eb 05 e8 ea 3c 9f f6 5b 41 5c 41 5e
RSP: 0018:ffffc900057a78f0 EFLAGS: 00010293
RAX: ffffffff8b287154 RBX: ffff88807ba72780 RCX: ffff8880213e8000
RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 0000000000000000
RBP: 00000000ffffffef R08: ffffffff9024cc67 R09: 0000000000000000
R10: fffff52000af4eb0 R11: fffffbfff204998d R12: dffffc0000000000
R13: ffffffff904a1080 R14: ffff888144ed0008 R15: ffff888144ed0e20
FS:  0000000000000000(0000) GS:ffff888124de6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005642de0a8a70 CR3: 000000007a40c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:253
 cleanup_net+0x572/0x810 net/core/net_namespace.c:706
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Fixes: 36fbf1e52b ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Reported-by: syzbot+74f338e09f1ef3ee6457@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a96219e.04428c52.29b18.0001.GAE@google.com/T/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260901005550.2042357-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 18:30:00 -07:00
Jun Yang
5a3f7a683a net: bridge: mcast: don't truncate the port group walk on teardown
__br_multicast_disable_port_ctx() and br_multicast_del_port() walk
port->mglist with hlist_for_each_entry_safe(). However,
br_multicast_find_del_pg() can also delete other entries from the same
list through br_multicast_fwd_src_remove() or __fwd_del_star_excl().

If such an entry is the iterator's saved next node, hlist_del_init()
clears its ->next and terminates the walk early. The reproducer triggers
this in both teardown walks, leaving port groups in the bridge mdb with
a dangling ->key.port after del_nbp() frees the port:

  BUG: KASAN: slab-use-after-free in __mdb_fill_info+0x1191/0x1320
   __mdb_fill_info+0x1191/0x1320
   br_mdb_dump+0x594/0xe40
   rtnl_mdb_dump+0x1cf/0x5d0

Use hlist_del_init_rcu() to unlink the group while preserving ->next.
br_multicast_del_pg() and the teardown walks run under
br->multicast_lock. The GC worker must acquire the same lock before
detaching the group for destruction, so the node remains alive while
the walk uses the preserved pointer.

Preserving ->next means a walk can now reach a group that an earlier
iteration already deleted as a side effect. That group is off mp->ports,
so br_multicast_find_del_pg() would fall through its port scan and hit
the trailing WARN_ON(1). Skip such groups at the top of that helper: a
port group is put on port->mglist when it is created and only unlinked
when it is deleted, so hlist_unhashed() identifies exactly this case.

Fixes: b08123684b ("net: bridge: mcast: install S,G entries automatically based on reports")
Cc: stable@vger.kernel.org
Suggested-by: Nikolay Aleksandrov <razor@blackwall.org>
Reported-by: TencentOS Corvus AI <corvus@tencent.com>
Signed-off-by: Jun Yang <junvyyang@tencent.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260831111330.199543-1-junvyyang@tencent.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 18:25:35 -07:00
Eric Dumazet
af602c7aa5 bonding: do not clear curr_active_slave prematurely when releasing all slaves
When releasing all slaves during bond destruction (all == true),
__bond_release_one() unconditionally clears bond->curr_active_slave to
NULL in every iteration.

If a backup slave is released before the active slave,
bond_alb_deinit_slave() triggers rlb_teach_disabled_mac_on_primary(),
which increments the active slave dev promiscuity counter and sets
bond_info->primary_is_promisc = 1.

Because bond->curr_active_slave was prematurely cleared to NULL when
releasing the backup slave, the subsequent iteration releasing the active
slave evaluates oldcurrent as NULL, so bond_change_active_slave(bond, NULL)
is skipped. Consequently, bond_alb_handle_active_change() is never called
to decrement the promiscuity counter, permanently leaking promiscuous
mode on the physical device after bond teardown.

When oldcurrent == slave, bond_change_active_slave(bond, NULL) already sets
bond->curr_active_slave to NULL. We only need to avoid selecting a new
active slave when all == true. Replace the if (all) branch with
if (!all && oldcurrent == slave).

Fixes: 0896341a44 ("bonding: fix bond_release_all inconsistencies")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jay Vosburgh <jv@jvosburgh.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260831203042.164466-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02 18:19:19 -07:00
Eduard Zingerman
ac0aaef0aa selftests/bpf: BPF_PSEUDO_FUNC reference to the main program
Add a test case for a BPF_PSEUDO_FUNC load instruction that references
the entry function of the program it belongs to. W/o the previous
patch the verifier accepts this program thus allowing a runtime call
at a bogus address. See previous patch for detailed description.

Main function needs to be marked with BTF_FUNC_STATIC for the test to
trigger the bug, the patch uses test_verifier harness instead of
test_prog because libbpf has no way to convey this.

Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260902233658.1186477-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-02 17:50:09 -07:00
Eduard Zingerman
374b2c5561 bpf: reject BPF_PSEUDO_FUNC reference to the main program
fixups.c:jit_subprogs() rewrites BPF_PSEUDO_FUNC loads to contain real
function addresses. This function is invoked from bpf_jit_subprogs()
only when env->subprog_cnt > 1. Meaning that for any program like
below:

  int main(void *ctx) {
    void *ptr = main;
    ...
    bpf_timer_set_callback(..., ptr);
    ...
  }

The 'ptr' won't be ever converted to contain an address.
In combination with e.g. bpf_timer_set_callback() this would lead to a
function call at a bogus address.

Instead of complicating the implementation, just assume that no useful
program needs main to be a sync or async callback and reject
BPF_PSEUDO_FUNC loads for the main subprogram.

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260902233658.1186477-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-02 17:50:09 -07:00
Masami Hiramatsu (Google)
0c4256196b kprobes: Protect kprobe_blacklist with RCU
__within_kprobe_blacklist() traverses kprobe_blacklist without holding
kprobe_mutex. When a module is unloaded, kprobe_remove_area_blacklist()
removes blacklist entries and immediately frees them with kfree().
A concurrent call to within_kprobe_blacklist() can therefore dereference
freed memory.

Furthermore, within_kprobe_blacklist() can be called in atomic or
non-preemptible contexts where the sleeping kprobe_mutex cannot be taken.

Protect kprobe_blacklist with RCU. Use guard(rcu)() and
list_for_each_entry_rcu() for traversal, list_add_tail_rcu() for
insertions, list_del_rcu() for deletions, and kfree_rcu() to reclaim
entries safely after a grace period.

Link: https://lore.kernel.org/all/178810004323.64882.16493230858653316962.stgit@devnote2/

Fixes: 376e242429 ("kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260807155802.F06041F000E9@smtp.kernel.org/
Assisted-by: Antigravity:gemini-3.7-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-09-03 09:04:25 +09:00
Henry Martin
86b7a239ec tracing/probes: Fix use-after-free on field name/type of events with multiple probes
The fields of a probe-based dynamic event (kprobe, uprobe, eprobe and
fprobe events) are created in traceprobe_define_arg_fields() by handing
the probe_arg name/type strings to trace_define_field(), which only
stores the pointers without copying. Those strings are owned by the
trace_probe and are freed when that probe is removed.

An event can have several probes attached. The field list is defined
only once, by the first probe that registers the event, but it is kept
alive by any surviving sibling probe. Deleting just that first probe by
symbol -

  # primary A: fields are defined from A's args
  echo 'p:kprobes/ev vfs_read  a1=$arg1' >  kprobe_events
  # append B: shares A's event call
  echo 'p:kprobes/ev vfs_write a1=$arg1' >> kprobe_events
  # delete only A (matched by symbol), B survives
  echo '-:kprobes/ev vfs_read'           >> kprobe_events

frees A's args (trace_probe_cleanup() -> traceprobe_free_probe_arg()),
but trace_probe_unlink() keeps the trace_probe_event because the probe
list is not empty. The event call stays registered via B while its
fields now reference freed memory. Any field lookup then reads it, e.g.

  echo 'a1 == 1' > events/kprobes/ev/filter

  BUG: KASAN: slab-use-after-free in strcmp+0xa7/0xb0
  Call Trace:
   strcmp
   trace_find_event_field
   parse_pred
   process_preds
   create_filter
   apply_event_filter
   event_filter_write

field->name references parg->name (kstrdup'd, freed with the probe) and,
for array arguments, field->type references parg->fmt (kmalloc'd, freed
with the probe) - the scalar type otherwise points at the static
fmttype rodata, which is safe.

Have traceprobe_define_arg_fields() duplicate the name and type strings
and anchor the copies on the trace_probe_event, which embeds the event
call and outlives every individual probe; trace_probe_event_free()
releases them.

The reproducer above triggers reliably; the field lookup and the delete
both run under event_mutex, so this is a dangling reference after
removal rather than a race.

The issue was found by the autokbug dynamic kernel fuzzer at Tencent
Yunding Lab.

Link: https://lore.kernel.org/all/20260826030009.1855331-1-bsdhenrymartin@gmail.com/

Fixes: ca89bc071d ("tracing/kprobe: Add multi-probe per event support")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-09-03 09:04:25 +09:00
Masami Hiramatsu (Google)
871e07b6e3 tracing/probes: Fix code indent in get_bitoffset_of_field()
Fix code block indentation introduced by commit f218345240
("tracing/probes: Support field specifier option for typecast").

Link: https://lore.kernel.org/all/178827252027.123716.7095571176291547259.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-09-03 09:04:25 +09:00
Masami Hiramatsu (Google)
47e93045a2 tracing/probes: Fix BTF kflag check for anonymous struct member access
btf_find_struct_member() traverses into nested anonymous structures and
unions to find a struct member. However, get_bitoffset_of_field() in
trace_probe.c checked btf_type_kflag(type) using the outer parent type
instead of the actual anonymous structure/union that directly contains
the found member.

If the parent structure and anonymous structure have mismatched kflags
(e.g., the parent has kflag=0 while the anonymous structure has kflag=1
because it contains bitfields), the bitfield size encoded in the upper
8 bits of member->offset is erroneously treated as part of the byte/bit
offset, corrupting the resolved offset and failing to set last_bitsize.
Similarly, btf_find_struct_member() pushed anonymous member offsets
onto anon_stack without masking BTF_MEMBER_BIT_OFFSET() when kflag is set.

To fix this problem, update btf_find_struct_member() to return actual
containing structure/union type via member_type, use appropriate
__btf_member_bit_offset() to get bit offset, and use member_type for
btf_type_kflag() in get_bitoffset_of_field().

Link: https://lore.kernel.org/all/178827250904.123716.17452648791331881284.stgit@devnote2/

Fixes: c440adfbe3 ("tracing/probes: Support BTF based data structure field access")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260822095110.0772E1F000E9@smtp.kernel.org/
Assisted-by: Antigravity:gemini-3.7-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-09-03 09:04:25 +09:00
Masami Hiramatsu (Google)
f36d94a20c tracing/probes: Fix anon_stack check for unnamed bitfields in btf_find_struct_member
btf_find_struct_member() traverses into nested anonymous structures
and unions by pushing members with !member->name_off onto anon_stack.
However, it does not consider the unnamed bitfields (e.g. `int : 5`
or `unsigned int : 0`) which also have member->name_off == 0.

If such an unnamed bitfield is pushed to anon_stack, the
btf_find_struct_member() return an error even if there are other
valid entries in anon_stack.

To fix this, only push unnamed struct/union members to anon_stack.
Also move the btf_type_is_struct() check to the entry of this function
because now it is sure only struct/union are pushed to anon_stack.

Link: https://lore.kernel.org/all/178827249775.123716.7813217688423513612.stgit@devnote2/

Fixes: 302db0f5b3 ("tracing/probes: Add a function to search a member of a struct/union")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260830143859.D56991F00A3D@smtp.kernel.org/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-09-03 09:04:25 +09:00
Linus Torvalds
940de590b8 hardening fix for v7.3-rc2
- Default randstruct off with rust for better allmodconfig coverage
   (Mark Brown)
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Merge tag 'hardening-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening fix from Kees Cook:

 - Default randstruct off with rust for better allmodconfig coverage
   (Mark Brown)

* tag 'hardening-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  hardening: Default randstruct off with rust for better allmodconfig support
2026-09-02 16:02:02 -07:00
Yogesh Mohan Marimuthu
13af55f713 drm/amdgpu/userq: fix struct drm_amdgpu_info_device padding for 32bit compile
need to pad before __u64 tcc_disabled_mask variable.

This patch fixes 64bit Kernel + 32 bit mesa combination. But at the same
time it will break 32bit Kernel(using this patch) + older 32bit mesa(not
using this patch).

This issue was discussd with alexander.deucher@amd.com,
christian.koenig@amd.com and pierre-eric.pelloux-prayer@amd.com.
Currently today 32 bit kernel + 32 bit userspace and 64 bit kernel and
64 bit userspace work.  Mixed 64 bit kernel and 32 bit userspace is
currently broken.  Since 32 bit kernel and userspace is probably pretty
rare these days and the data affected by this is not critical, Hence
we can go ahead with this patch.

Fixes: cf21e76a60 ("drm/amdgpu: return tcc_disabled_mask to userspace")
Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohanmarimuthu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 497b5090f2857ef8ad9a162aa31ada0de5814663)
2026-09-02 17:02:23 -04:00
Yuling Li
6293f2e143 drm/amd/display: Fix cursor disable with horizontally split planes
[WHY]
resource_can_pipe_disable_cursor() disables the hardware cursor on a
pipe when a higher layer fully covers that pipe's recout, to avoid
double-cursor and scaling artifacts.

When merging pipe-split halves of the same overlay layer, the inner
loop walks every pipe above the current one and looks for siblings
sharing test_pipe's layer_index. Because test_pipe itself satisfies
that condition, it can be treated as its own split partner. That
incorrectly doubles r2.width and makes the covering check succeed even
when the overlay does not fully contain the underlying pipe.

On horizontally split or multi-quadrant layouts this causes the cursor
to disappear over overlay regions while input/coordinate mapping remains
correct.

[HOW]
Skip test_pipe when searching for a pipe-split sibling on the same
layer, so only the other half of the split plane is merged into r2.

Signed-off-by: Yuling Li <yulingli@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 85ccd2c39cca9351d4db393e24acea8bf943d350)
2026-09-02 17:02:04 -04:00
Sunil Khatri
8b4a4193f3 drm/amdgpu/userq: dont overwrite the error of subsequent map call
If a queue fails to map that we need to return the error code back
to the caller and not overwrite with a success specifically.

Accumulate the failure and return that.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 42a0197d10039e9518c0324c43331eb22b44d5f8)
2026-09-02 17:01:16 -04:00
Kanala Ramalingeswara Reddy
a26301203a drm/amdgpu: Skip accessing psp rum time db for APUs
Psp runtime DB is for dGPUs only.

Signed-off-by: Kanala Ramalingeswara Reddy <Kanala.RamalingeswaraReddy@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit dce8195027f146467c9378efb2bb1b0859cb735e)
Cc: stable@vger.kernel.org
2026-09-02 17:00:42 -04:00
Sunil Khatri
49a74a2388 drm/amdgpu: update the fw version for gfx12 userqueues
Update to the latest stable fw versions where userqueues
is working as it is expected with major fixes.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 69fa36e3ac92f2544ee7a1b719ec212b8247a2da)
Cc: stable@vger.kernel.org
2026-09-02 17:00:16 -04:00
Sunil Khatri
c748dd03df drm/amdgpu: update the fw version for gfx11 userqueues
Update to the latest stable fw versions where userqueues
is working as it is expected with major fixes.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d50201b891604ab97f305d4a20d888ba93305b48)
Cc: stable@vger.kernel.org
2026-09-02 16:59:48 -04:00
Sunil Khatri
3b5c4f4a47 drm/amdgpu: fix byte/dword unit mismatch in coredump IB dump
In amdgpu_devcoredump_print_ibs(), the NO_CPU_ACCESS VRAM path passed
cursor.start/4 and cursor.size/4 to amdgpu_device_mm_access(), but that
function's pos/size parameters are byte offsets/lengths (confirmed by
amdgpu_ttm_vram_mm_access() and leading to wrong size calculation.

Similarly with that change the off index needs to be calculated
based on dword since that is a u32 type.

Fixes: 7b15fc2d1f ("drm/amdgpu: dump job ibs in the devcoredump")
Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 1bd613b0ed98a23575b18674c94b8b3392614681)
Cc: stable@vger.kernel.org
2026-09-02 16:59:25 -04:00
Mario Limonciello
012a026bae drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds
Reading /sys/kernel/debug/kfd/mqds while a process holds an active KFD
queue triggers a NULL pointer dereference because the for loop that
calls mqd_mgr->debugfs_show_mqd() is incorrectly placed outside the
if (pqn->q) block that initializes mqd_mgr.

The queue list can contain entries where pqn->q is NULL (kernel queues
where only pqn->kq is valid). In the original code:

  if (pqn->q) {
      ...
      mqd_mgr = q->device->dqm->mqd_mgrs[mqd_type];
      size = mqd_mgr->mqd_stride(...);
  }

  for (xcc = 0; xcc < num_xccs; xcc++) {  // WRONG: outside if block
      mqd = q->mqd + size * xcc;
      r = mqd_mgr->debugfs_show_mqd(m, mqd);
  }

When iterating over a queue node where pqn->q is NULL:
1. The if (pqn->q) block is skipped
2. mqd_mgr remains uninitialized (NULL from declaration)
3. The for loop executes anyway
4. mqd_mgr->debugfs_show_mqd(m, mqd) dereferences NULL

The crash manifests as:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor instruction fetch in kernel mode
  RIP: 0010:0x0
  Call Trace:
   pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu]
   kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu]
   seq_read_iter+0x132/0x4b0
   ...

Fix by moving the for loop inside the if (pqn->q) block, so mqd_mgr
and related variables are only used when properly initialized.

Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5689
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260831130051.2031435-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)
Cc: stable@vger.kernel.org
2026-09-02 16:58:54 -04:00
Hari Mishal
f63de9054d drm/amd/display: fix division by zero in get_estimated_bw()
get_estimated_bw() divides by link->dpia_bw_alloc_config.bw_granularity,
which is zeroed by reset_bw_alloc_struct() and only populated once
DP_TUNNELING_BW_ALLOC_CAP_CHANGED has been handled.

link_dp_dpia_handle_bw_alloc_status(), the DPCD interrupt handler,
calls get_estimated_bw() whenever DP_TUNNELING_ESTIMATED_BW_CHANGED
is set, independently of whether DP_TUNNELING_BW_ALLOC_CAP_CHANGED
has ever fired for that link. A connected USB4/DPIA tunneling device
that reports an estimated-bandwidth change before ever reporting a
capability change drives a division by zero in this IRQ path.

link_dpia_send_bw_alloc_request() already guards the same
bw_granularity division; add the identical guard here rather than
introducing a new pattern.

Fixes: 8e5cfe547b ("drm/amd/display: upstream link_dp_dpia_bw.c")
Reviewed-by: Alex Hung <alex.hung@amd.com>
Assisted-by: gkh_clanker_t1000
Signed-off-by: Hari Mishal <harimishal1@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit f2a961457c33dc34223aad5c9e8971de34a4eed3)
Cc: stable@vger.kernel.org
2026-09-02 16:57:38 -04:00
Melissa Wen
4278d65a41 drm/amd/display: use halving distribution for all encode-to-linear curves
In encode-to-linear conversions, LUT entries should be uniformly
distributed across the input range: non-linear encodings are already
approximately perceptually uniform, so every input code carries the same
weight. A fixed count per region does the opposite, concentrating
entries on the darker values and leaving few for the bright end, whereas
halving distribution spaces all 256 entries uniformly. This holds for
any encoded input, so remove the PQ/sRGB condition from commit
"drm/amd/display: use halving distribution for PQ/sRGB linearizing LUT"
and apply halving to all encode-to-linear operations
(pre-defined TF or user LUTs).

It fixes the following IGT kms_colorop subtests:
- plane-XR30-XR30-srgb_inv_eotf_lut-srgb_eotf_lut
- plane-XR30-XR30-gamma_2_2-gamma_2_2_inv-gamma_2_2

Fixes: a71d2b051f ("drm/amd/display: use halving distribution for PQ/sRGB linearizing LUT")
Reviewed-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6df7c9c307e72e7f13829e94edc89134f0764775)
2026-09-02 16:54:09 -04:00
Roman Li
5a67d2e055 drm/amd/display: Fix backlight control for luminance-capable OLED
[WHY]
For some eDP panels VESA aux backlight control is necessary,
otherwise they stay black.

[HOW]
When AUX backlight control is used, select BACKLIGHT_CONTROL_VESA_AUX for
panels that advertise panel_luminance_control.

Reviewed-by: Hansen Dsouza <hansen.dsouza@amd.com>
Signed-off-by: Roman Li <Roman.Li@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 42f698bd061d76d5f4c84a195e465cfbeec775e4)
2026-09-02 16:51:47 -04:00
Austin Zheng
93a77d353c drm/amd/display: Remove const Qualifier From Non-Pointer Fields
[WHY/HOW]
Integer values for
dml2_core_calcs_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport_params
should not have the const qualifier.
This prevents using different values of the inputs when the
function is called again.

Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 342280aae4f33816e8d07c15cb538a3b375a7f8f)
Cc: stable@vger.kernel.org
2026-09-02 16:49:34 -04:00
Roman Li
9ce3169430 drm/amd/display: Set gpuvm min page size to 4K on dcn35/36
[WHY]
Splash screen corruption on some 8K monitors.

[HOW]
Set GPUVM min page size to 4K for DCN35/36 to use the correct DML2
calculations, avoiding the corruption path observed during splash.

Fixes: 115009d11c ("drm/amd/display: Add DCN35 DML2 support")
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Roman Li <Roman.Li@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 2cbfb03dead5088a7bdfe2ce392a5caa3d1b3719)
Cc: stable@vger.kernel.org
2026-09-02 16:47:56 -04:00
Ivan Lipski
ef0e9d1272 drm/amd/display: Fix DCN5/6 DML2 compilation warnings
[WHY]
A kernel compilation warning was reported caused by upstream of DCN5/6.

[HOW]
Using plain integer as NULL pointer. Assign NULL to the
VActiveLatencyHidingMargin/VActiveLatencyHidingUs pointer members in
dml2_core_dcn5_funcs_mode_programming.c, and pass NULL for the pointer
arguments to calculate_first_second_splitting() in
dml2_pmo_dcn6_stage_optimizers.c.

Fixes: 7f7d7ea1fa ("drm/amd/display: Add new sources for DCN6")
Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d96880560e9f35ba7f8de1b3f90032c8c3eaea88)
2026-09-02 16:47:00 -04:00
Sunil Khatri
90ce19bd11 drm/amdgpu: fix Idle BOs list in VM debugfs status info
amdgpu_debugfs_vm_bo_status_info() prints the "Idle BOs" section by
iterating lists->needs_update, the same list already printed just
above under "Moved BOs". struct amdgpu_vm_bo_status has a dedicated
idle list, populated whenever a BO's state machine settles, but it
was never read here, so genuinely idle BOs never show up in the
debugfs output and the "Idle BOs" section duplicates "Moved BOs"
instead.

Iterate lists->idle for the "Idle BOs" section.

Fixes: 4cdbba5a16 ("drm/amdgpu: restructure VM state machine v4")
Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 451bfc778a8c364841837def00ba15936f72762b)
Cc: stable@vger.kernel.org
2026-09-02 16:34:08 -04:00
Sunil Khatri
d6e16df7df drm/amdgpu: use AMDGPU_GPU_PAGE_SHIFT instead of PAGE_SHIFT
For different address types the variable PAGE_SHIFT might
not work well and it's better to use the GPU specific one

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 3494b77d10375e0f9ab784e9b20763339844b55b)
Cc: stable@vger.kernel.org
2026-09-02 16:33:37 -04:00
Amber Lin
b428f83c7c drm/amdgpu: Update queue reset support version
Update queue reset required MES version for MES 12.1 to 0x7b since we
change the implementation from detect-and-reset method to
per-queue-reset method.

Signed-off-by: Amber Lin <amber.lin@amd.com>
Reviewed-by: Michael Chen <michael.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 2160a5cbf0b7917adce4b55421306b614b4a2c8f)
2026-09-02 16:32:47 -04:00
Alex Deucher
7346a046c6 drm/amdgpu/gfx8: only apply compute quantums to KCQs
Don't apply to KIQ.  Seems to cause problems on KIQ
on some ARM platforms.

Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5658
Fixes: 91cf34bc5a ("drm/amdgpu/gfx8: align mqd settings with KFD")
Reviewed-by: Jesse Zhang <jesse.zhang@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6aae7bab029cdccae9a7157facfe36bfc35fc940)
Cc: stable@vger.kernel.org
2026-09-02 16:31:18 -04:00
Mario Limonciello
bd1f08246b drm/amdgpu: restrict BAR0 fallback read to SR-IOV VFs only
The BAR0 fallback read path was introduced as a workaround for SR-IOV VFs
where the VRAM aperture is not available during early init. Restrict this
workaround to only SR-IOV VFs where it's needed.

Reported-by: gloveless@jqluv.com
Fixes: cba4928cdf ("drm/amdgpu: reduce early full GPU access during SR-IOV init")
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260826185102.2269511-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d8a0affd207c813bd063fa2c27786f449eaf92b8)
2026-09-02 16:29:24 -04:00
Priya Hosur
94e25cb6ab drm/amdkfd: Add TLB flush after MES queue eviction/suspension
MES (Micro Engine Scheduler) does not perform heavy-weight TLB
invalidation after unmapping queues, unlike HWS which does this
automatically. This causes a race condition where in-flight DMA
descriptors can access memory that has been unmapped, leading to page
faults and GPU queue hangs during SVM page migration.

The issue manifests as KFDSVMRangeTest.MultiThreadMigrationTest
failures on gfx1151 (Strix Point) with XNACK mode 1 enabled - the GPU
compute queue hangs with packets submitted but never consumed.

Add kfd_flush_tlb() calls after MES queue removal in two locations:
- evict_process_queues_cpsch(): after all queues removed during eviction
- suspend_queues(): after debug/criu queue suspension (with mem_fence barrier)

This ensures all in-flight memory accesses from unmapped queues are
flushed before memory is freed or migrated.

Signed-off-by: Priya Hosur <Priya.Hosur@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit f5c4f88e0f9c45a8fb9dfac0c1df726c95e41b77)
Cc: stable@vger.kernel.org
2026-09-02 16:20:48 -04:00
Chris Mason
6a7a45b1d9 MAINTAINERS: update Chris Mason's email address
David Sterba has been doing the Btrfs maintainership work for years, and
my email update to mason@kernel.org seems like a good time to make the
MAINTAINERS file a little more accurate.

Link: https://lore.kernel.org/all/20260827193032.786461-1-clm@meta.com/
Signed-off-by: Chris Mason <clm@meta.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
Qu Wenruo
0c1032c8c3 btrfs: tests: do not touch page cache if root/inode allocation failed
Inside test_find_delalloc() of extent-io-tests.c, if we fail to allocate
a dummy root or the test inode, we go to out label to clean up.

But at that stage, @inode is still NULL and we will call
process_page_range() to access the page cache of the inode, this will
cause NULL pointer dereference.

This is a very minor bug, as it only affects selftests which are not
compiled in by default for most distros, and very hard to trigger.

Fix it by adding a new out_root_info label to handle root and inode
allocation failure.

This is a pre-existing bug reported by Sashiko while reviewing another
patch.

Link: https://sashiko.dev/#/patchset/cover.1786095309.git.wqu%40suse.com
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
FAN YE
2acb9f3d1c btrfs: zstd: fix lost wakeup when waiting for a workspace
A writer can sleep forever in zstd_get_workspace() even though a workspace
is free.  When zstd_alloc_workspace() fails, the task is queued on
zwsm->wait and schedules unconditionally, never re-testing the pool.
zstd_put_workspace() publishes the workspace and then calls cond_wake_up(),
which only wakes when a sleeper is already visible, so a workspace returned
between the failed allocation and prepare_to_wait() wakes nobody.  The
window is wide: zstd_alloc_workspace() goes through kvmalloc() and may
enter reclaim.

Only a max level workspace triggers the wakeup and one is deliberately kept
allocated as the fallback every waiter waits for, so once its wakeup is
lost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens
to return one.  Re-check the pool after prepare_to_wait() has published the
waiter, and use the workspace if one turned up.

Fixes: 3f93aef535 ("btrfs: add zstd compression level support")
Assisted-by: Claude:claude-opus-5
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: FAN YE <fy15309206903@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
Qu Wenruo
cacf358322 btrfs: do not force reloc root creation during qgroup_account_snapshot()
[BUG]
When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota",
it has a high chance to trigger the following kernel warning and flips
the fs RO:

  BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup
  ------------[ cut here ]------------
  WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173
  CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full)  3adc6528fb66f7a55fe1095385818e742f200aab
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
  RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs]
  Call Trace:
   <TASK>
   insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   __btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   __btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
   __x64_sys_ioctl+0x416/0x9a0
   do_syscall_64+0xe1/0x790
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
   </TASK>
  ---[ end trace 0000000000000000 ]---
  BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2
  BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173
  	item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33
  		extent refs 1 gen 222 flags 2
  		ref#0: tree block backref root 266
         [ Skip the tree dump ]
  	item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33
  		extent refs 1 gen 162 flags 258
  		ref#0: tree block backref root 267
  BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0
  BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117

[CAUSE]
The above error is showing that there is a tree reference to a metadata
extent that is no longer there.

With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is
some extra debug output:

  BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0
  BTRFS error (device dm-2):   root entry 256, num_refs 18446744073709551615
  BTRFS error (device dm-2):   root entry 273, num_refs 18446744073709551615
  BTRFS error (device dm-2):   Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1
     btrfs_force_cow_block+0x129/0x7d0 [btrfs]
     btrfs_cow_block+0x10a/0x250 [btrfs]
     btrfs_search_slot+0x5eb/0xf40 [btrfs]
     btrfs_insert_empty_items+0x3a/0x70 [btrfs]
     insert_with_overflow+0x53/0x130 [btrfs]
     btrfs_insert_dir_item+0x125/0x290 [btrfs]
     btrfs_add_link+0xaa/0x410 [btrfs]
     btrfs_rename+0x5ea/0xcd0 [btrfs]
     btrfs_rename2+0x28/0x60 [btrfs]
     vfs_rename+0x5b2/0xe10
     filename_renameat2+0x244/0x430
     __x64_sys_rename+0x48/0x70
     do_syscall_64+0xe1/0x790
     entry_SYSCALL_64_after_hwframe+0x4b/0x53
  BTRFS error (device dm-2):   Ref action 2, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 18446744073709551615
     btrfs_force_cow_block+0x327/0x7d0 [btrfs]
     btrfs_cow_block+0x10a/0x250 [btrfs]
     btrfs_search_slot+0x5eb/0xf40 [btrfs]
     btrfs_lookup_file_extent+0x4d/0x70 [btrfs]
     btrfs_drop_extents+0x151/0xf00 [btrfs]
     insert_reserved_file_extent+0xfe/0x3e0 [btrfs]
     btrfs_finish_one_ordered+0x549/0xc40 [btrfs]
     btrfs_work_helper+0xde/0x350 [btrfs]
     process_one_work+0x198/0x380
     worker_thread+0x1c8/0x330
     kthread+0xee/0x120
     ret_from_fork+0x28f/0x310
     ret_from_fork_asm+0x11/0x20
  BTRFS error (device dm-2):   Ref action 1, root 273, ref_root 0, parent 4594335744, owner 0, offset 0, num_refs 1
     __btrfs_mod_ref+0x1c5/0x2d0 [btrfs]
     btrfs_copy_root+0x262/0x390 [btrfs]
     create_reloc_root+0xb9/0x370 [btrfs]
     btrfs_init_reloc_root+0xb0/0x1b0 [btrfs]
     record_root_in_trans+0xa6/0xd0 [btrfs]
     create_pending_snapshot+0x383/0xf00 [btrfs]
     create_pending_snapshots+0x9b/0xc0 [btrfs]
     btrfs_commit_transaction+0x280/0xeb0 [btrfs]
     prepare_to_relocate+0x147/0x200 [btrfs]
     relocate_block_group+0x6b/0x5e0 [btrfs]
     btrfs_relocate_block_group+0x92c/0x2380 [btrfs]
     btrfs_relocate_chunk+0x3f/0x1a0 [btrfs]
     btrfs_balance+0xa2c/0x19c0 [btrfs]
     btrfs_ioctl+0x2839/0x2d30 [btrfs]
     __x64_sys_ioctl+0x416/0x9a0
     do_syscall_64+0xe1/0x790

The above shows the direct cause, Ref action 3 is the oldest operation,
which shows the tree block is created by COW.  Then ref action 2 shows
it's COWed away, by a metadata update, meaning the tree block is already
released, should not be referred any more.

Then the final one, is trying to create a reloc tree for subvolume 273,
and that reloc root creation is referring to the already dropped tree
block.

The root cause is that, during qgroup_account_snapshot(), we are calling
record_root_in_trans() with "force = true".
So if the root has no reloc root, we will create one, but at that
timing it's already too late.

Normally reloc root should be created before the commit and current
roots diverge, to avoid the same problem we are hitting.

But during relocation initialization, we are committing the current
running transaction, with a new reloc_control attached halfway.

And if qgroup is enabled, the record_root_in_trans() with "force = true"
calls will force reloc root creation even if we do not and should not
create reloc root at that timing.

[FIX]
Do not force reloc root creation during record_root_in_trans() with
"force = true" cases, which is only called by qgroup_account_snapshot().

If we're really under relocation, the reloc root should be created way
early, before the commit and current root diverge.  If the root has no
reloc tree yet, it means we're still initializing the reloc, and do not
need a reloc root.

So skipping the reloc tree creation in qgroup_account_snapshot() should
be safe.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1275740
Fixes: 4d31778aa2 ("btrfs: qgroup: Fix root item corruption when multiple same source snapshots are created with quota enabled")
Assisted-by: LLM (initial analysis, but incorrect conclusion with too many burnt tokens)
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
Avi Weiss
d0285dfbc3 btrfs: send: fix lost error return value in will_overwrite_ref()
The direct-return refactoring in commit b3047a42f5 ("btrfs: send:
directly return from will_overwrite_ref() and simplify it") changed
will_overwrite_ref() to return directly instead of going through the
common out label.

That resulted in a negative return value from is_inode_existent() to
start being converted to 0, making lookup errors unable to be
distinguished from the inode not existing.

process_recorded_refs() expects negative errors from
will_overwrite_ref() and aborts processing when it receives one.

Return the value from is_inode_existent() to restore the previous error
propagation behavior as it was before the refactor.

Fixes: b3047a42f5 ("btrfs: send: directly return from will_overwrite_ref() and simplify it")
Signed-off-by: Avi Weiss <thnkslprpt@gmail.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
Leo Martins
529c01c3dc btrfs: abort transaction before releasing tree_log_mutex on commit failure
When transaction metadata writeout fails in btrfs_commit_transaction(),
the current code only logs the error, drops tree_log_mutex and then goes
through cleanup_transaction(), which aborts the transaction and records
the fs error.

That is too late for the tree log side. A log sync can already be
waiting on tree_log_mutex, because the committing transaction is moved
to TRANS_STATE_UNBLOCKED while that mutex is held, which lets fsyncs
join the next transaction and queue up in btrfs_sync_log(). Once the
failed commit drops tree_log_mutex, such a log sync acquires it, sees
BTRFS_FS_ERROR() still clear, and writes super_for_commit. That
superblock holds the roots prepared for the transaction that has just
failed to write out its metadata, so it can point at tree blocks that
never reached the disk, and the next mount fails with a parent transid
mismatch.

Commit 165ea85f14 ("btrfs: do not write supers if we have an fs
error") fixed this class of problem by making btrfs_sync_log() check for
an fs error right after taking tree_log_mutex. That check only works if
the commit path publishes the fs error before it releases the same
mutex, and commit 68d4ece9c3 ("btrfs: don't call
btrfs_handle_fs_error() in btrfs_commit_transaction()") removed the only
thing that did so.

Restore the ordering by aborting the transaction while tree_log_mutex is
still held. We have a transaction handle here, so this does not need to
bring back the btrfs_handle_fs_error() call: __btrfs_abort_transaction()
records the fs error itself, which is all btrfs_sync_log() looks at, and
the error message put in its place is kept.

This is what commit 3810ab40af ("btrfs: abort transaction on error in
write_all_supers()") already does for the next call in this function.

This is reproducible on an unmodified kernel by failing the first
couple of bios of a transaction commit with fail_make_request while a
concurrent fsync workload keeps log syncs queued on tree_log_mutex.

Fixes: 68d4ece9c3 ("btrfs: don't call btrfs_handle_fs_error() in btrfs_commit_transaction()")
CC: stable@vger.kernel.org # 7.0+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: jlayton@meta.com <jlayton@meta.com>
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:30 +02:00
Johannes Thumshirn
c428b763f2 btrfs: zoned: propagate do_zone_finish() error in btrfs_zone_finish_endio()
btrfs_zone_finish_endio() ignored the return value of do_zone_finish()
and always returned 0, silently dropping a failed zone finish.

Instead propagate any error from do_zone_finish() as the caller
btrfs_finish_ordered_io() already handles it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02 22:19:29 +02:00