The interface name is passed in a fixed length (TIPC_MAX_IF_NAME) buffer.
Replace the strcpy(data, l->if_name) with memcpy() so that the
pad bytes are actually written (l->if_name[] is zero padded)
rather than sending random bytes from the skb to the remote system.
Replace two other strcpy() with strscpy().
Fixes: e74a386d70 ("tipc: remove pre-allocated message header in link struct")
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Link: https://patch.msgid.link/20260829115813.188600-1-david.laight.linux@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
User-space applications can bind a large number of service addresses to
one or more sockets. Each binding of a local-scope service address inserts
one entry (publication) into the TIPC name table. If the number of these
publications exceeds TIPC_MAX_PUBL (65535), protocol service types
(such as node state and link state) are no longer inserted into the name
table. This causes two issues:
1. User-space applications subscribing to node or link up/down events
stop receiving notifications.
2. A NULL pointer dereference can occur:
BUG: kernel NULL pointer dereference, address: 00000000000000d0
...
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc4-default+ #5 PREEMPT(full)
...
RIP: 0010:tipc_named_node_up (./include/linux/skbuff.h:2251 net/tipc/name_distr.c:195 net/tipc/name_distr.c:221)
...
Call Trace:
<IRQ>
tipc_node_write_unlock (net/tipc/node.c:428)
tipc_rcv (net/tipc/node.c:934 net/tipc/node.c:2189)
tipc_udp_recv (net/tipc/udp_media.c:389)
Thread 1 (tipc_net_finalize) | Thread 2 (named_distribute)
-----------------------------|-----------------------------
| ...
| list_for_each_entry(publ, pls, binding_node) {
| ...
| __skb_queue_tail(list, skb);
| ...
| }
| ...
| hdr = buf_msg(skb_peek_tail(list));
... |
tipc_nametbl_publish(); |
If 'tipc_nametbl_publish()' (Thread 1) fails because the number of
local publications reaches TIPC_MAX_PUBL, list (Thread 2) will be empty. As a
result, NULL is passed to 'buf_msg()', leading to a NULL pointer dereference.
Fix these issues by allowing protocol service types (node state, link state,
and topology server) to be inserted into the name table unconditionally.
This ensures that users subscribing to these types always receive
notifications. In addition, the maximum number of local user publications is
reduced to (TIPC_MAX_PUBL - 1). This ensures that the maximum bulk size
calculated in tipc_link_set_queue_limits() remains valid.
Fixes: a5e7ac5ce1 ("tipc: fix regression bug where node events are not being generated")
Reported-by: Xiang Mei <xmei5@asu.edu>
Tested-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Link: https://patch.msgid.link/20260827111418.164957-1-tung.quang.nguyen@est.tech
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ido Schimmel says:
====================
Mitigate a side channel in routing exception caches
When an ICMP error that quotes a UDP packet is locally delivered, the
kernel only creates a routing exception if the quoted packet matches
a socket. This allows an off-path attacker to conduct a side-channel
attack on the routing exception caches in order to discover the
ephemeral ports used by connected UDP sockets.
Previous mitigations tried to make it harder for attackers to find hash
collisions in these caches and make the eviction of exceptions less
predictable. Amit Klein and Noam Caspi demonstrated that both of these
mitigations can be bypassed.
This patchset tries to mitigate such attacks by always creating an
exception, even before trying to find a matching socket. The exception
is created by the same helpers that are used when the quoted packet did
not originate from a socket, so that guesses (right or wrong) from an
off-path attacker always result in an exception being created or updated
in the cache that the attacker can observe.
Note that this mitigation does not make it easier for attackers to fill
these caches, since they can already create exceptions with little to no
validation. For example, by sending an ICMP error that quotes an ICMP
Echo Reply or one that quotes a UDP source port that matches a wildcard
socket.
In the good case (matched socket) this comes at the cost of an extra
route lookup, as the exception is created before the one performed by
the socket path. When the two lookups resolve to different nexthops,
an exception is created in the cache of each.
Patch #1 fixes a pre-existing bug in the handling of ICMPv6 Redirect
Message packets. Discovered while writing the selftest.
Patch #2 creates an exception from the IPv4 UDP code even before socket
matching. Other socket types do not need this: raw sockets have no
ports, and for TCP the ICMP error is discarded unless the quoted
sequence number is in window.
Patch #3 does the same for IPv6.
Patch #4 adds a selftest.
v1: https://lore.kernel.org/netdev/20260826143735.1819315-1-idosch@nvidia.com/
====================
Link: https://patch.msgid.link/20260828192344.2596928-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a test for the IPv4 and IPv6 exception caches, covering the
exceptions that are created in response to ICMP errors quoting a UDP
packet.
The topology consists of a host (h1) that reaches a remote host (h2)
via a router (r1), with a second router (r2) attached to the segment
shared by h1 and r1. UDP packets are injected using a packet socket, so
that an ICMP error quoting them is only matched to a socket when one was
opened separately with the same source port. PMTU errors are provoked by
lowering the MTU of the far end of the path and redirects by pointing
r1's route towards h2 back over the segment it received the packet from.
The following is tested for both address families and for both PMTU and
redirect exceptions:
* An error that is not matched to a socket creates an exception that
carries the new MTU or gateway.
* An error that is matched to a socket creates the same exception.
The PMTU tests further verify that a lower PMTU replaces the one stored
in the exception whereas a higher one does not, and that a socket which
disabled PMTU discovery using IP{,V6}_PMTUDISC_OMIT gets the same
exception as the other cases.
Without "ipv4: udp: Create exceptions before socket matching" and "ipv6:
udp: Create exceptions before socket matching", the tests that do not
open a socket fail:
# ./exception_cache.sh
TEST: IPv4: PMTU: exception without a matching socket [FAIL]
No socket: exception does not carry an MTU of 1400
TEST: IPv6: PMTU: exception without a matching socket [FAIL]
No socket: exception does not carry an MTU of 1400
TEST: IPv4: PMTU: exception with a matching socket [ OK ]
TEST: IPv6: PMTU: exception with a matching socket [ OK ]
TEST: IPv4: PMTU: exception with a socket ignoring it [FAIL]
PMTU discovery disabled: exception does not carry an MTU of 1400
TEST: IPv6: PMTU: exception with a socket ignoring it [FAIL]
PMTU discovery disabled: exception does not carry an MTU of 1400
TEST: IPv4: Redirect: exception without a matching socket [FAIL]
No socket: exception does not carry the new gateway
TEST: IPv6: Redirect: exception without a matching socket [FAIL]
No socket: exception does not carry the new gateway
TEST: IPv4: Redirect: exception with a matching socket [ OK ]
TEST: IPv6: Redirect: exception with a matching socket [ OK ]
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828192344.2596928-5-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, when ICMPv6 Packet Too Big and Redirect Message packets are
locally delivered and quote a UDP packet, an exception is only created
in the IPv6 exception cache if the kernel can match the UDP packet to an
existing socket.
This behavior allows off-path attackers to conduct a side-channel attack
on the exception cache in order to discover the ephemeral port used by a
connected UDP socket.
Commit 4785305c05 ("ipv6: use siphash in rt6_exception_hash()") and
commit a00df2caff ("ipv6: make exception cache less predictible") tried
to mitigate such attacks by making it harder for attackers to discover
hash collisions in the exception cache and by randomizing the number of
exceptions a hash bucket can hold, respectively. Unfortunately, both of
the mitigations can be bypassed.
Instead, mitigate such attacks by always creating an exception, even
before trying to find a matching socket. Do that by calling
ip6_update_pmtu() and ip6_redirect(), the helpers used when the quoted
packet did not originate from a socket.
This means that guesses (right or wrong) from an off-path attacker will
always result in an exception being created or updated in the cache that
the attacker can observe.
Pass the ifindex of the ingress device and the default uid, in a similar
fashion to icmpv6_err(). Unlike IPv4, an oif of 0 would not match any
nexthop in ip6_redirect_nh_match() and no exception would be created in
response to a Redirect Message.
Note that this does not allow attackers to create exceptions that they
could not create before, as both helpers can already be reached with
little to no validation. For example, by sending an ICMPv6 error that
quotes an ICMPv6 Echo Reply or one that quotes a UDP source port that
matches a wildcard socket.
Also note that in the good case (matched socket) the above scheme comes
at the cost of an extra route lookup, as the no socket helpers perform
their own lookup before the one performed by ip6_sk_update_pmtu() /
ip6_sk_redirect(). When the two resolve to different nexthops, it also
results in two exceptions being created for the same destination IP. One
in the exception cache of the nexthop resolved by the no socket helpers
and another in the exception cache of the nexthop used by the socket.
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Cc: stable@vger.kernel.org
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Noam Caspi <noam.caspi@mail.huji.ac.il>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260828192344.2596928-4-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, when ICMP Fragmentation Needed and Redirect Message packets
are locally delivered and quote a UDP packet, a FIB nexthop exception
(FNHE) is only created if the kernel can match the UDP packet to an
existing socket.
This behavior allows off-path attackers to conduct a side-channel attack
on the FNHE cache in order to discover the ephemeral port used by a
connected UDP socket.
Commit 6457378fe7 ("ipv4: use siphash instead of Jenkins in
fnhe_hashfun()") and commit 67d6d681e1 ("ipv4: make exception cache
less predictible") tried to mitigate such attacks by making it harder
for attackers to discover hash collisions in the FNHE cache and by
randomizing the number of exceptions a hash bucket can hold,
respectively. Unfortunately, both of the mitigations can be bypassed.
Instead, mitigate such attacks by always creating a FNHE, even before
trying to find a matching socket. Do that by calling ipv4_update_pmtu()
and ipv4_redirect(), the helpers used when the quoted packet did not
originate from a socket.
This means that guesses (right or wrong) from an off-path attacker will
always result in a FNHE being created or updated in the cache that the
attacker can observe.
Pass an oif of 0, in a similar fashion to icmp_err(). This is also the
oif used by the socket path for sockets that are not bound to a device.
Note that this does not allow attackers to create FNHEs that they could
not create before, as both helpers can already be reached with little to
no validation. For example, by sending an ICMP error that quotes an ICMP
Echo Reply or one that quotes a UDP source port that matches a wildcard
socket.
Also note that in the good case (matched socket) the above scheme comes
at the cost of an extra route lookup, as the no socket helpers perform
their own lookup before the one performed by ipv4_sk_update_pmtu() /
ipv4_sk_redirect(). When the two resolve to different nexthops, it also
results in two exceptions being created for the same destination IP. One
in the FNHE cache of the nexthop resolved by the no socket helpers and
another in the FNHE cache of the nexthop used by the socket.
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Cc: stable@vger.kernel.org
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Noam Caspi <noam.caspi@mail.huji.ac.il>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260828192344.2596928-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an ICMP Redirect Message is matched to a socket, both IPv4 and IPv6
verify that the source IP of the ICMP packet is the current gateway for
the quoted packet. Both also pass the socket's bound device as the
expected nexthop device.
The difference is that IPv4 treats "oif=0" as "any", whereas IPv6 always
requires an exact match (see ip6_redirect_nh_match()), since the gateway
address is usually a link-local address.
Therefore, when an IPv6 UDP/RAW socket is not bound to a device, the
above verification fails and an exception is not created. This also
happens when the socket is bound to a VRF, as l3mdev_update_flow()
resets the oif to 0.
Fix this by passing the ifindex of the ingress device as the expected
nexthop device. This is consistent with the existing callers of
ip6_redirect(). Note that for ICMPv6 Redirect Message packets the VRF
driver does not reset skb->dev to the VRF device, so skb->dev is
correct, even when it is a VRF port.
Fixes: b55b76b221 ("ipv6:introduce function to find route for redirect")
Cc: stable@vger.kernel.org
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828192344.2596928-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Shuangpeng Bai reported a KASAN slab-use-after-free in
ip6gre_tunnel_xmit().
The precise KASAN bug was caused by ip6_tnl_xmit() consuming the
skb during headroom expansion and returning an error, while
ip6gre_tunnel_xmit() still held the stale pointer and called
skb_tunnel_info_txcheck(skb) at tx_err. That specific bug was fixed by
commit 87f21b59dd ("ip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()").
However, calling skb_tunnel_info_txcheck(skb) at the tx_err label
after the transmission attempt remains problematic:
Downstream helpers like ip6_tnl_xmit() call skb_scrub_packet(),
which drops the skb's metadata_dst before transmission. If an error
occurs later during transmit, inspecting skb at tx_err sees a scrubbed
dst and misclassifies tx_errors vs tx_dropped.
Commit e5f7e211b6 ("ip6gre: avoid tx_error when sending MLD/DAD on
external tunnels") already handled this correctly in
ip6erspan_tunnel_xmit() by checking and caching tun_info before
transmit.
Align ip6gre_tunnel_xmit() with ip6erspan_tunnel_xmit() by caching
tun_info before xmit and checking it at tx_err.
Fixes: e5f7e211b6 ("ip6gre: avoid tx_error when sending MLD/DAD on external tunnels")
Reported-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Closes: https://lore.kernel.org/netdev/20260819062224.3197349-1-shuangpeng.kernel@gmail.com/
Cc: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828103731.1951815-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Eric Dumazet says:
====================
ipv6: mcast: RCU and timer fixes
This series addresses several RCU synchronization and timer calculation
issues identified in IPv6 multicast (MLD) handling within net/ipv6/mcast.c
while I was working on fixing a syzbot report in net/ipv4/icmp.c.
Patch 1 fixes an RCU reader diversion in ip6_mc_del1_src() where mutating
psf->sf_next to insert an unlinked source node into the tombstone list
diverted concurrent lockless readers (e.g. ipv6_chk_mcast_addr()) into
pmc->mca_tomb, causing them to miss remaining active sources.
Patch 2 converts ip6_mc_source() to use copy-on-write RCU updates.
Previously, source additions and deletions modified the socket's
psl->sl_addr array in-place, causing concurrent lockless readers in
inet6_mc_check() (UDP/RAW receive path) to observe torn 16-byte IPv6
addresses or duplicated/missed sources.
Patch 3 fixes delay calculation in igmp6_join_group() when canceling an
existing delayed work, preventing unsigned jiffies underflows when the
timer has already expired and clamping the delay to the unsolicited report
interval.
Patch 4 ensures rcu_assign_pointer() is consistently used for __rcu list
updates in __ipv6_dev_mc_dec(), ipv6_sock_mc_drop(), __ipv6_sock_mc_close(),
and related helpers.
Patch 5 switches igmp6_mc_seq_show() to use jiffies_delta_to_clock_t()
with a signed long delta, preventing underflows in /proc/net/igmp6 timer
duration reporting.
====================
Link: https://patch.msgid.link/20260828084531.1826790-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If a multicast group timer has expired but the delayed work has
not yet run to clear MAF_TIMER_RUNNING, expires - jiffies produces
a negative value.
Because unsigned arithmetic was used with jiffies_to_clock_t(),
expires - jiffies underflows to a huge value and reports invalid
timer durations in /proc/net/igmp6.
Use jiffies_delta_to_clock_t() with a signed long delta to properly
cap expired deltas to 0, matching IPv4 igmp_mc_seq_show() and commit
a399a80531 ("time: jiffies_delta_to_clock_t() helper to the rescue").
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828084531.1826790-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Several places in net/ipv6/mcast.c update RCU-protected lists
(np->ipv6_mc_list, idev->mc_list, idev->mc_tomb) using direct pointer
assignments instead of rcu_assign_pointer():
1. In __ipv6_dev_mc_dec(), unlinking a group from idev->mc_list did:
*map = ma->next;
without rcu_assign_pointer() while concurrent readers traverse
idev->mc_list locklessly under rcu_read_lock().
2. In ipv6_sock_mc_drop() and __ipv6_sock_mc_close(), unlinking a group
from np->ipv6_mc_list directly assigned *lnk = mc_lst->next and
np->ipv6_mc_list = mc_lst->next without rcu_assign_pointer(), racing
with lockless readers in inet6_mc_check().
3. In __ipv6_sock_mc_join(), mc_lst->next was initialized to
np->ipv6_mc_list via raw assignment before publishing mc_lst.
4. In mld_del_delrec() and __ipv6_dev_mc_inc(), __rcu source pointers
passed into rcu_assign_pointer() lacked explicit dereference helpers.
Fix these by consistently using rcu_assign_pointer() along with
mc_dereference() / sock_dereference().
Fixes: 456b61bca8 ("ipv6: mcast: RCU conversion")
Fixes: 88e2ca3080 ("mld: convert ifmcaddr6 to RCU")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828084531.1826790-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When joining a multicast group, if a report work is already pending
(e.g. scheduled by a query or a previous join), igmp6_join_group()
cancels the delayed work and recalculates the delay:
if (cancel_delayed_work(&ma->mca_work)) {
refcount_dec(&ma->mca_refcnt);
delay = ma->mca_work.timer.expires - jiffies;
}
Unlike igmp6_group_queried(), igmp6_join_group() did not check
if delay >= interval. This leads to two issues:
1. If the timer has already expired (timer.expires <= jiffies), the
stale expiry is reused by mod_delayed_work(), causing the second
unsolicited report to fire on the very next tick without a
randomized delay.
2. If the timer was originally armed by a query with a large
maximum response delay, delay could exceed
unsolicited_report_interval(ma->idev).
Fix this by initializing delay to unsolicited_report_interval(ma->idev)
and re-randomizing it with get_random_u32_below(interval) when
delay >= interval, mirroring the logic in igmp6_group_queried().
Fixes: 2d9a93b490 ("mld: convert from timer to delayed work")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://patch.msgid.link/20260828084531.1826790-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pmc->sflist is read locklessly under rcu_read_lock() by
inet6_mc_check() during packet reception in the UDP and RAW
multicast receive paths.
ip6_mc_source() mutated psl->sl_addr and psl->sl_count in-place
when adding or removing a source filter. Additionally, when expanding
the filter buffer, newpsl was published via rcu_assign_pointer()
before writing the new source into the array.
Because 16-byte struct in6_addr writes are not atomic and array
shifting is not synchronized with RCU readers, concurrent readers in
inet6_mc_check() could read torn IPv6 addresses or observe
duplicated/missed source entries.
Fix this by switching ip6_mc_source() to copy-on-write RCU updates:
allocate and fully populate newpsl before publishing it via
rcu_assign_pointer(), and reclaim the old filter via kfree_rcu(),
matching ip6_mc_msfilter().
Also remove the now unused IP6_SFBLOCK macro.
Fixes: 882ba1f73c ("mld: convert ipv6_mc_socklist->sflist to RCU")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828084531.1826790-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When removing a source filter whose count reaches zero, ip6_mc_del1_src()
unlinks psf from pmc->mca_sources. If the filter was previously active,
the code moved psf directly into pmc->mca_tomb by updating psf->sf_next.
Because pmc->mca_sources is traversed locklessly under RCU (e.g. by
ipv6_chk_mcast_addr()), mutating psf->sf_next before a grace period
elapses diverts concurrent readers to the tombstone list. Consequently,
readers miss remaining active sources in pmc->mca_sources and improperly
examine deleted tombstone entries.
Fix this by allocating a new tombstone node for pmc->mca_tomb (as done
in sf_setstate()) and retiring the original psf via kfree_rcu().
Fixes: 4b200e3989 ("mld: convert ip6_sf_list to RCU")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260828084531.1826790-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tty_ldisc_hangup() invokes the hangup callback while holding only a read
lock on tty->ldisc_sem, so it can run concurrently with other line
discipline callbacks. This currently forces async PPP to maintain
separate lifetime protection around tty->disc_data.
Line discipline close is called under the write lock during hangup
processing. Remove the hangup callback and rely on close for teardown,
as done for SLIP by commit 23c53269f2 ("slip: remove slip_hangup() to
fix use-after-free in slip_receive_buf()"). This serializes teardown
with all other line discipline operations.
disc_data_lock, refcount and completion are redundant with that
serialization. Remove them and access tty->disc_data directly.
This also eliminates a lockdep warning reported by syzbot. The warning
does not indicate a real deadlock because the write side runs only in
process context with hardirqs disabled.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+8e808eb853386f575d86@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/0000000000002fbad30611e25849@google.com/
Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260828073245.126804-1-qingfang.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 23d2b94043 ("igmp: Add ip_mc_list lock in ip_check_mc_rcu")
added spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a
use-after-free while iterating im->sources during concurrent deletions.
However, ip_check_mc_rcu() is called from RCU read-side critical
sections in packet receive and route lookup fast paths (e.g.
__mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()).
When igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and
calls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(),
an XFRM policy matching a multicast destination triggers
xfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() ->
ip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock
is already held on the same CPU, triggering a lockdep recursive locking
warning / deadlock.
Fix this by converting IPv4 struct ip_sf_list to RCU, mirroring the
IPv6 implementation in net/ipv6/mcast.c:
1. Add struct rcu_head to struct ip_sf_list and annotate sf_next,
sources, and tomb as __rcu pointers.
2. Use rcu_assign_pointer() and kfree_rcu() for list updates and
deletions.
3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse
im->sources locklessly with for_each_psf_rcu(), reading and writing
counter fields with READ_ONCE() and WRITE_ONCE().
Note: RCU conversion of /proc/net/mcfilter will be done in a
separate patch.
Fixes: 23d2b94043 ("igmp: Add ip_mc_list lock in ip_check_mc_rcu")
Reported-by: syzbot+3d99fb01bcd740f2fc1e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3d99fb01bcd740f2fc1e
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260827160656.903003-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fl_set_enc_opt() iterates the key's nested tunnel-option attributes
with nla_for_each_attr() while advancing a single mask pointer via
nla_next() at the bottom of each loop, so the mask cursor is driven
by the number of key attributes rather than by the mask's own
attributes. The nla_ok() added by commit c96adff956 ("cls_flower:
call nla_ok() before nla_next()") only validates the mask pointer
that was just consumed; the pointer produced by nla_next() is used by
the next iteration (fl_set_geneve_opt() and siblings) without any
validation.
The mask's nested attributes are validated with NL_VALIDATE_LIBERAL,
which merely warns on trailing bytes that do not form a complete
attribute. A mask carrying one valid attribute plus 1-3 residue
bytes (or a non-aligned attribute length making msk_depth negative)
therefore reaches the next iteration with msk_depth != 0, so neither
the !msk_depth check in fl_set_enc_opt() nor the !depth check in the
per-type helpers fires. nla_type() then reads past the mask payload
and nla_parse_nested_deprecated() iterates with an nla_len taken
from those bytes, reading well beyond the mask attribute (KASAN:
slab-out-of-bounds read in __nla_validate_parse from fl_change()).
Validate the advanced mask pointer as well: when the mask is not
legitimately exhausted (msk_depth != 0) and the new pointer fails
nla_ok(), reject the filter with -EINVAL. An exactly exhausted mask
still skips the check, preserving exact-match behaviour for the
remaining key attributes.
Fixes: c96adff956 ("cls_flower: call nla_ok() before nla_next()")
Reported-by: TencentOS Corvus AI <corvus@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Aohan Mei <henrymei@tencent.com>
Link: https://patch.msgid.link/20260826025123.62758-1-ljp1205831794@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daehyeon Ko says:
====================
vsock: validate packet sources after bound lookup fallback
Both virtio and VMCI look up connected sockets by the full tuple before
falling back to a destination-only bound lookup. The fallback can select a
non-listening socket without validating the packet source.
V2 covered only the virtio path. Following Stefano's review, this series
moves the source and transport validation into a documented AF_VSOCK helper
and uses it for both virtio and VMCI. The VMCI patch checks both its
bottom-half and deferred workqueue receive paths.
V4 preserves VMCI's existing RST behavior when source validation fails.
The reset is addressed from the received packet so that a bound but
non-listening or concurrently closed socket still notifies the sender,
without directing the reset to a connected socket's stored peer.
The v3 regression was reproduced in three x86_64 KASAN boots: a REQUEST to
a bound but non-listening socket returned VMCI_ERROR_NO_ACCESS but no RST
arrived within one second. With v4, the sending context received the
expected RST in all three boots. The original VMCI source-validation oracle
also passed in three v4 boots: a matched RST reset the pending socket while
a mismatched-context RST left it pending. No KASAN report occurred.
Patch 1 is unchanged from v3 (identical stable patch-id) and carries
Bobby's Reviewed-by for that revision. Its v3 validation covered the
cross-UID injection oracle, local CID aliases, selected VSOCK selftests,
and W=1 changed-object builds under allmodconfig and allyesconfig.
The current-tree guest-CID vhost probe could not be rerun because the test
user lacks access to /dev/vhost-vsock.
====================
Link: https://patch.msgid.link/20260826003929.966160-1-4ncienth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vmci_transport_recv_stream_cb() looks up sockets first by the full source
and destination tuple, then by destination only in the bound table. The
fallback can select a non-listening socket without checking whether the
packet came from its stored peer.
This was reproduced with two VMCI contexts. A RST from the context not
stored in a TCP_SYN_SENT socket reset that socket after it was selected by
the destination-only lookup.
VMCI can process notification packets in bottom-half context when the
socket is not owned by user context, or defer packets to a workqueue. Use
vsock_check_source() after taking the socket lock in the bottom-half path,
and recheck after lock_sock() in the workqueue path. Listening sockets
continue to accept packets from any source.
Reply with a RST addressed from the received packet before dropping a
source that fails validation. This preserves the existing reset behavior
for bound non-listening and concurrently closed sockets without directing
the reset to a connected socket's stored peer.
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/netdev/20260814121255.6B5001F000E9@smtp.kernel.org/
Cc: stable@vger.kernel.org
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Reviewed-by: Vishnu Dasa <vishnu.dasa@broadcom.com>
Link: https://patch.msgid.link/20260826003929.966160-3-4ncienth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
virtio_transport_recv_pkt() looks up sockets first by the full source and
destination tuple, then by destination only in the bound table. The
fallback is needed for listening and connecting sockets, but sockets remain
in the bound table after connect(), so it can also return a non-listening
socket.
The fallback does not validate the source address. In TCP_SYN_SENT, a
RESPONSE from an unrelated source can transition the victim socket to
TCP_ESTABLISHED while its stored remote address remains unchanged.
Subsequent RW packets from that source are delivered through the same
destination-only fallback.
This was reproduced with capability-empty processes under different UIDs.
The attacker discovered the target tuple through unprivileged AF_VSOCK
sock_diag and caused the victim socket to read 16 attacker-chosen bytes;
the intended peer-side socket read 0 of those 16 bytes.
Add vsock_check_source() to validate the transport, source port and source
CID against the peer stored in a non-listening socket. The local transport
is the CID exception because its packets are generated internally with
VMADDR_CID_LOCAL as their source, including connections using CID aliases.
Use the helper after lock_sock() in the virtio receive path.
Fixes: 06a8fc7836 ("VSOCK: Introduce virtio_vsock_common.ko")
Closes: https://lore.kernel.org/netdev/20260813121236.2328599-1-4ncienth@gmail.com/
Cc: stable@vger.kernel.org
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Link: https://patch.msgid.link/20260826003929.966160-2-4ncienth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
page_pool_alloc_frag_netmem() rounds the requested fragment size with
size = ALIGN(size, dma_get_cache_alignment());
dma_get_cache_alignment() returns 1 unless the architecture defines
ARCH_DMA_MINALIGN, which DMA-coherent architectures such as x86 do not.
There the ALIGN() is a no-op and pool->frag_offset advances by the raw,
unrounded size.
A single caller asking for an odd size then leaves frag_offset misaligned
for every fragment carved out of that page afterwards. The pool is shared,
so the damage is not confined to the caller that caused it.
The per-cpu system_page_pool used by generic XDP hits this.
skb_pp_cow_data() allocates its fragments with the raw packet length:
size = min_t(u32, len, PAGE_SIZE);
truesize = size;
page = page_pool_dev_alloc(pool, &page_off, &truesize);
leaving frag_offset odd for whatever is carved out of that page next. Its
own head allocation is already aligned -- SKB_HEAD_ALIGN(size) plus the
XDP_PACKET_HEADROOM its callers pass -- so it is a later user of the shared
pool that pays: page_pool_dev_alloc_va() returns a misaligned buffer,
napi_build_skb() installs it as skb->head, and skb_shinfo(skb) ==
skb->head + skb->end is misaligned with it.
skb_shinfo()->dataref is a 4-byte atomic_t at offset 0x20, so the
atomic_inc() in __skb_clone() straddles a cache line. On x86 with split
lock detection -- fatal for kernel split locks by default -- this panics
the machine:
Oops: Split lock detected
RIP: 0010:skb_clone+0x154/0x1e0
Call Trace:
<IRQ>
raw_local_deliver+0x1ed/0x2c0
ip_protocol_deliver_rcu+0x54/0x1c0
ip_local_deliver_finish+0x85/0x100
ip_local_deliver+0x67/0x100
__netif_receive_skb_one_core+0x85/0xa0
process_backlog+0x87/0x130
Reproduced by attaching any generic-mode XDP program to loopback and
opening a RAW IPPROTO_UDP socket, which makes raw_local_deliver() clone
every locally delivered UDP packet; ordinary DNS traffic then triggers it,
roughly once per 2500 clones. Observed on 6.12.101 and 7.1.8.
Tracing page_pool_alloc_frag_netmem() over one such run shows the
amplification -- two odd-sized requests, nine misaligned offsets:
requested size & 7: 0: 17035 5: 1 7: 1
frag_offset & 7: 0: 17028 3: 1 4: 1 5: 1 6: 1 7: 5
and skb_pp_cow_data() returning heads that were aligned on entry:
head 0xffff8f4c86aeac00 -> 0xffff8f4c53a9a9c4 (&7=4)
head 0xffff8f4d6a8a42c0 -> 0xffff8f4c4f7b7a45 (&7=5)
Round the fragment size up to at least the alignment struct skb_shared_info
requires, so fragments are always suitably aligned for the objects callers
build on them. Architectures needing a larger DMA alignment keep it.
This also makes the remainder computed in page_pool_alloc_netmem(),
*size = max_size - *offset;
aligned, since max_size is a power of two -- which fixes the matching
misalignment of skb->end.
Verified with a controlled A/B under QEMU/KVM: same tree, same config,
same compiler, same rootfs and identical traffic, differing only by this
patch. A SEC("xdp.frags") XDP_PASS program on lo plus UDP datagrams
larger than max_head_size drives skb_pp_cow_data()'s fragment loop, which
passes raw packet lengths to the pool. Measured at the return of
skb_pp_cow_data():
unpatched patched
skb_pp_cow_data calls 40800 40800
misaligned skb->head 1120 0
dataref at line offset >60 80 0
The last row counts the accesses that actually fault:
skb_shinfo()->dataref sits at head+end+0x20 and is a 4-byte atomic, so
`lock incl` splits a 64-byte cache line only when that address lands at
offset 61..63. All 80 occurrences were at offset 61; the panic reported
above was at offset 62. Eliminating the misalignment removes every one
of them.
Same class of bug as commit 3bed3cc415 ("net: Do not allocate page
fragments that are not skb aligned"), which fixed the older
netdev_alloc_frag()/napi_alloc_frag() allocators.
Fixes: 53e0961da1 ("page_pool: add frag page recycling support in page pool")
Cc: stable@vger.kernel.org
Signed-off-by: Florian Schauer <florian@schauer.to>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260828060822.2628276-1-florian@schauer.to
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a tdc test case that fills the u32 node ID space with 4095
auto-generated handles, then attempts to add a 4096th. On the fixed
kernel the 4096th filter is rejected with ENOSPC (exit 2). On the
unfixed kernel it silently succeeds with a duplicate handle.
The setup pipes the 4095 add commands directly into `tc -b -` inside a
single bash -c (matching the existing test id 1234 pattern), avoiding
any temp file.
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260825081052.133898-2-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gen_new_kid() falls back to returning max (htid | 0xFFF) when both
idr_alloc_u32() ranges are full, instead of reporting an error.
u32_change() trusts that value and inserts a new knode with a handle
that is already live in the hash table, breaking handle uniqueness
within the table's node ID space.
The handle was never reserved in ht->handle_idr, so every later error
path that does idr_remove(&ht->handle_idr, handle) removes the
reservation of a different, live knode, which is then reused — one
failed add compounds into further duplicates.
The 4095 limit is per (table, bucket) — ht->handle_idr is per hash
table and the range is derived from htid (bucketid), so a table with
divisor 256 can legitimately hold 256*4095 knodes.
The sibling helper gen_new_htid() has the same silent in-band failure:
it returns 0 when the tp_c handle pool (1..0x7FF) is full, and
u32_init() publishes the root hash table with handle 0 without
checking. Two root tables with handle 0 alias in u32_lookup_ht(),
allowing cross-tcf_proto knode add/lookup/delete. Add the same
exhaustion check that the divisor path already has.
Return an error so u32_change() fails with ENOSPC/ENOMEM when the
node ID space is exhausted, and so u32_init() fails with -ENOMEM
when the hash table ID space is exhausted. The extack message
distinguishes pool exhaustion (-ENOSPC) from a transient allocation
failure (-ENOMEM).
Conditions to recreate the bug:
- CONFIG_NET_SCHED=y, CONFIG_CLS_U32=y (or =m with module loaded)
- Create a clsact qdisc on a device, then add 4095 u32 filters with
auto-generated handles to fill the node ID space for the root hash
table (single bucket). The 4096th auto-handle filter add triggers
the duplicate handle (fh 800::fff reused). Reachable at Level 2
(unshare -Urn, namespace-local CAP_NET_ADMIN).
- For gen_new_htid: create 2047 u32 proto entries on the same block
to fill the tp_c handle pool, then create one more. The root table
gets handle 0 and aliases with other handle-0 root tables.
Fixes: 7801db8aec ("net_sched: avoid generating same handle for u32 filters")
Reported-by: vega@nebusec.ai
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260825081052.133898-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Selvamani Rajagopal says:
====================
Fix to possible skb leak due to race condtion in tx path
Now the traffic is handled in threaded IRQ, and the
disable_traffic flag is checked before handling the
data, new race condition is exposed, in which
buffer may leak, if threaded IRQ interrupts the
trasmit path midway.
With this change, disable_traffic and waiting_tx_skb
pointer are protected by spin lock/unlock pair.
This is highlighted in Sashiko review
https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260611-level-trigger-v5-0-4533a9e85ce2%40onsemi.com
Also on buffer overrun condition, probably due to loss of
SPI data chunks, receive path doesn't see the expected
data chunk with end_valid bit set. As a result, driver
keeps adding data chunks to the skb before running out
of space and kernel panic is seen.
With this change, before adding data to the skb, if there
is no space, skb is freed and driver starts looking for
new frame by looking for a data chunk with start_valid
bit set.
[ 705.405490] skbuff: skb_over_panic: text:ffffffd2eb72a264 len:1600 put:64 head:ffffff804e5cdc40 data:ffffff804e5cdc80 tail:0x680 end:0x640 dev:eth1
[ 705.405569] ------------[ cut here ]------------
[ 705.405575] kernel BUG at net/core/skbuff.c:214!
[ 705.405589] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
[ 6703.427690] Call trace:
[ 705.925157] skb_panic+0x58/0x68 (P)
[ 705.928726] skb_put+0x74/0x80
[ 705.931772] oa_tc6_update_rx_skb+0x44/0x98 [oa_tc6_mod]
[ 705.937084] oa_tc6_macphy_threaded_irq+0x3f4/0x900 [oa_tc6_mod]
[ 705.943084] irq_thread_fn+0x34/0xb8
[ 705.946654] irq_thread+0x1a0/0x300
[ 705.950134] kthread+0x138/0x150
[ 705.953356] ret_from_fork+0x10/0x20
====================
Link: https://patch.msgid.link/20260824-fix-race-condition-and-crash-v7-0-4323279b18f2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Inadvertently bool data type is used where int is supposed to
be used. This might turn a negative error code into true or
false and sign of the return code would be lost.
Fixes: 8f9bf857e4 ("net: ethernet: oa_tc6: implement internal PHY initialization")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260824-fix-race-condition-and-crash-v7-4-4323279b18f2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Previously, TX queue interface was stopped when
disable_traffic flag was set, which would indicate fatal
error. It is more appropriate to disable the queue as,
unless driver is unloaded and reloaded, there is no recovery
after disable_traffic is set.
Queues may be re-enabled inadvertently by other layers.
Intention of disable_traffic is only to stop the traffic
from flowing on fatal error.
Fixes: b542d13fab ("net: ethernet: oa_tc6: Interrupt is active low, level triggered.")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260824-fix-race-condition-and-crash-v7-3-4323279b18f2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When oversubscribed traffic causes lot of buffer overflow errors,
probably due to loss of data chunks, driver fails to find a
data chunk with end_valid bit set, before it runs out of sk buffer
space. As a result, assert is seen during skb_put.
Now, check is made if skb buffer has enough tailroom for the
incoming data before accepting. If there is no room, current
frame is abandoned and it will start looking for a data chunk
with start_valid bit, that is a new frame.
SK buffer allocation error is considered as recoverable error.
rx_buf_overflow flag is too specific and no longer the only
condition this flag is used for. Therefore it is renamed as
wait_until_start_valid. This is more appropriate as this flag
is used to look for the next data chunk with SV bit set, after
failures like buffer overflow, buffer allocation failure, skb pointer
validity besides buffer overflow error.
Not writing to status0 if it reads 0.
Fixes: d70a0d8f2f ("net: ethernet: oa_tc6: implement receive path to receive rx ethernet frames")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260824-fix-race-condition-and-crash-v7-2-4323279b18f2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Threaded IRQ uses waiting_tx_skb. Transmit path also uses this pointer
without any mutual exclusion protection. As a result, it might leak skb
buffer, particularly if threaded IRQ sets disable_traffic true after
start_xmit already checked and found that disable_traffic being false,
if they happen to run on different cores.
On fatal error, where disable_traffic is set, transmit function drops the
packet and return NETDEV_TX_OK. Due to this change, skb_linearize call
is moved up to the beginning of the transmit function.
Since skb buffer may be freed from different contexts, dev_kfree_skb_any
is used to free skb buffer now, replacing one of the kfree_skb call.
oa_tc6_exit disables the irq before setting disable_traffic true.
Fixes: b542d13fab ("net: ethernet: oa_tc6: Interrupt is active low, level triggered.")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260824-fix-race-condition-and-crash-v7-1-4323279b18f2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
iucv_sock_recvmsg() sends the HiperSockets-only AF_IUCV_FLAG_WIN without
testing the transport, so on a classic z/VM socket iucv_send_ctrl() sizes
the skb through a NULL iucv->hs_dev. SO_MSGLIMIT accepts 1, so msglimit / 2
is zero and one recvmsg() on its own socket is enough for an unprivileged
process to take a spurious disconnect.
It also calls iucv_send_ctrl() under spin_lock_bh(&message_q.lock), which
allocates GFP_KERNEL inside a section the code treats as atomic. Sending
outside that lock lets two recvmsg() reach afiucv_hs_send() at once, where
msg_recv is sampled for the advertised window and subtracted after
dev_queue_xmit() -- and sendmsg reaches that counter under lock_sock()
while recvmsg holds no socket lock, so both can subtract the same value,
the counter goes negative and the credit reaches the peer twice.
Test the transport, claim the credit with atomic_xchg() after the last
error exit and hand it back if the transmit fails, and send once the lock
is dropped.
Fixes: 3881ac441f ("af_iucv: add HiperSockets transport")
Fixes: 238965b71b ("net/af_iucv: build proper skbs for HiperTransport")
Cc: stable@vger.kernel.org
Tested-by: Aswin Karuvally <aswin@linux.ibm.com>
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://patch.msgid.link/20260828-b4-disp-33fac0ed-v3-1-e6d061880ee0@proton.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
wait_on_bit_timeout() returns 0 if the bit was cleared, -EINTR if the
process received a signal and the mode permitted wake up on that signal,
or -EAGAIN if the timeout elapsed. It never returns 1.
Hence the check "err == 1" in mrvl_load_firmware() is dead code: when
the waiting task is interrupted by a signal (-EINTR), the code falls
into the "else if (err)" branch and misreports it as "Firmware request
timeout" with -ETIMEDOUT instead of propagating -EINTR.
Fix this by testing for -EINTR so that an interrupted firmware load is
properly detected and reported.
Fixes: 162f812f23 ("Bluetooth: hci_uart: Add Marvell support")
Signed-off-by: Gongwei Li <ligongwei@kylinos.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_ecred_defer_connect() clears FLAG_DEFER_SETUP also for channels
with different PID/PSM, which will not be added to the same
ECRED_CONN_REQ in any case. Consequently, only one ECRED connection
group can work at a time although it appears intended they would be
separate for each PID/PSM combination.
Fix by clearing FLAG_DEFER_SETUP only for the connections that could be
added in the request. Retain test_bit(FLAG_DEFER_SETUP) before calling
get_peer_pid as it may be NULL otherwise.
Fixes: da49b602f7 ("Bluetooth: L2CAP: Use DEFER_SETUP to group ECRED connections")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_chan_connect() tries to ensure there are no more than
L2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the
same L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs.
However, the check only counts deferred channels. If 6 L2CAP sockets
are connected at the same time in order DDDDND (D=deferred,
N=non-deferred), the last can bump the total to max+1. It results to
one __le16 written out of bounds of the scid array, and an invalid
ECRED_CONN_REQ being sent.
Fix by leaving room for the non-deferred pending ECRED channels in the
counting in l2cap_chan_connect(), so the limit can't be exceeded.
Move counting under same critical section where the channel is added.
Although race conditions involving this appear unreachable, it's easier
to see.
Also add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this
less brittle.
Fixes: da49b602f7 ("Bluetooth: L2CAP: Use DEFER_SETUP to group ECRED connections")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_new_connection() sets default value of channel mode to match the
parent channel. l2cap_le_connect_req() left this at the default, and
created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that
mode. This causes FLAG_DEFER_SETUP channels to reply to
L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect.
It can also result to stack OOB write (of l2cap_alloc_cid determined
values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not
limit maximum number of deferred channels or check for duplicate ident.
Fix by setting chan->mode correctly in l2cap_le_connect_req().
Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE
instead of OOB write to make it less brittle.
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
In hci_register_dev(), the power_on work item is queued to
hdev->req_workqueue before initializing hdev->adv_monitors_idr and
registering the MSFT extension via msft_register(). For devices marked with
quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on
the device. When the power_on work item runs concurrently on another CPU,
hci_power_on() detects that the device is unconfigured and immediately
invokes hci_dev_do_close(), which calls msft_do_close().
Concurrently, msft_register() allocates the msft structure and exposes it
to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If
msft_do_close() executes while hdev->msft_data is already assigned but the
mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates
on an uninitialized mutex, triggering a DEBUG_LOCKS warning:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common
kernel/locking/mutex.c:625 [inline]
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550
kernel/locking/mutex.c:821
...
Call Trace:
<TASK>
msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693
hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522
hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
kthread+0x388/0x470 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>
Fix this by moving the queue_work() call in hci_register_dev() to after
idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device
structures and extensions are fully initialized before asynchronous tasks
can access them. Additionally, assign hdev->msft_data in msft_register()
only after mutex_init(&msft->filter_lock) has completed.
Fixes: 9e14606d8f ("Bluetooth: msft: Extended monitor tracking by address filter")
Assisted-by: Gemini:gemini-3.7-flash Gemini:gemini-3.1-pro-preview syzbot
Reported-by: syzbot+14ce1b05b7d5a989abbe@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=14ce1b05b7d5a989abbe
Link: https://syzkaller.appspot.com/ai_job?id=2bc9e8aa-ca6d-43e2-be2c-fd5d9f649d7e
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
btintel_read_version_tlv() ignores the parser return value, so setup
continues with partially initialized version data after a malformed TLV
causes parsing to stop.
Return the parser error to the caller so an invalid response fails setup
instead of being treated as successful. Keep this behavioral change
separate from the bounds checks so it can be reverted independently if
an existing controller sends malformed data.
Signed-off-by: Laxman Acharya Padhya <acharyalaxman8848@gmail.com>
Reviewed-by: Ali Ahmet Memis <ali@iusegentoo.com>
Tested-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The firmware ID is treated as a NUL-terminated string even though the
TLV length is its only boundary. If the value does not contain a NUL
terminator, snprintf() can read beyond the received response.
Limit the conversion to the advertised TLV value length.
Fixes: 164c62f958 ("Bluetooth: btintel: Add firmware ID to firmware name")
Reviewed-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Laxman Acharya Padhya <acharyalaxman8848@gmail.com>
Tested-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
btintel_parse_version_tlv() verifies that a complete TLV is present in
the response, but it does not ensure that the value is long enough for
the specific TLV type. A short value can therefore cause an
out-of-bounds read through get_unaligned_le16(), get_unaligned_le32(),
or memcpy().
Reject values shorter than the minimum required by each known TLV type.
Also reject responses that do not contain the Command Complete Status
field.
Fixes: 57375beef7 ("Bluetooth: btintel: Add infrastructure to read controller information")
Reviewed-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Laxman Acharya Padhya <acharyalaxman8848@gmail.com>
Tested-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
On spurious interrupt where the TX and RX causes are not set, driver was
not clearing the auto mask which can block all the interrupts. Driver
needs to clear the automask even if no causes are set.
Fixes: c2b636b3f7 ("Bluetooth: btintel_pcie: Add support for PCIe transport")
Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
npc_mcam_free_all_entries() disables every MCAM entry mapped to a
port before freeing it. On CN20K, that also disables the default
broadcast, multicast, promiscuous, and unicast rules, which causes
packet drops when all rules are removed per port.
Only disable and free non-default entries. Leave CN20K default rules
enabled when freeing the remaining port entries.
Fixes: 013717353c ("octeontx2-af: npc: cn20k: Tear down default MCAM rules explicitly on free")
Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot reported the following circular locking dependency:
xs->mutex -> netdev lock -> pnodes_lock -> net->xdp.lock -> xs->mutex
The pnodes_lock -> net->xdp.lock edge is recorded when
ipvlan_device_event(NETDEV_UNREGISTER) calls unregister_netdevice_many()
while holding pnodes_lock. A nested NETDEV_UNREGISTER notification for
an IPvlan device enters xsk_notifier(), which acquires net->xdp.lock.
Keep pnodes_lock only while marking the upper devices as dying, removing
them from port->ipvlans, and queueing them for unregistration. Once the
devices have been detached from the protected list, release pnodes_lock
before unregister_netdevice_many() invokes notifier callbacks.
The port remains alive across unregistration because
ipvlan_device_event() holds the reference acquired by ipvlan_port_get().
The dying flag prevents a concurrent ->dellink() callback from deleting a
queued device again.
Fixes: 35add1093e ("ipvlan: Protect ipvl_port.ipvlans with mutex.")
Reported-by: syzbot+aa48b5fe7bfda62d1682@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=aa48b5fe7bfda62d1682
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260828164918.451364-1-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every
MDBE_ATTR_SRC_LIST member, accepts the all-zeros address.
A source list is only accepted on a (*, G) entry, whose source is the
all-zeros address, and for each member of the list an (S, G) entry is
derived from it by substituting the source. Entries are keyed by a plain
memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present
and holds the all-zeros address and the source list holds it as well, the
derived (S, G) key is byte-identical to the (*, G) key and resolves to the
same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is
then left with a zero address family.
vxlan_mdb_remote_src_del() removes the forwarding entry of a source before
freeing the source entry:
vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr);
vxlan_mdb_remote_src_entry_del(ent);
With the keys aliased, the first call deletes the remote of the entry that
owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second
call then runs on the freed entry, and its hlist_del() reads ->pprev and
->next out of it and writes through them.
Adding the (*, G) entry with NLM_F_REPLACE and no source list marks the
all-zeros source for deletion and reaches this from the sweep at the end
of vxlan_mdb_remote_srcs_replace().
BUG: KASAN: slab-use-after-free in __vxlan_mdb_add+0x1cd/0xd70
Read of size 8 at addr ffff888102852500 by task poc/84
__vxlan_mdb_add+0x1cd/0xd70
vxlan_mdb_add+0xc0/0x140
rtnl_mdb_add+0x157/0x2a0
rtnetlink_rcv_msg+0x207/0x5a0
Allocated by task 84:
__kmalloc_cache_noprof+0x153/0x360
vxlan_mdb_remote_srcs_add+0x2eb/0x440
__vxlan_mdb_add+0x803/0xd70
Freed by task 84:
kfree+0x14c/0x3b0
vxlan_mdb_remote_del+0x129/0x1a0
__vxlan_mdb_del+0x4f/0xe0
vxlan_mdb_remote_src_fwd_del.isra.0+0x162/0x1b0
__vxlan_mdb_add+0x1c5/0xd70
The MDB operations are netns-scoped, so an unprivileged user can perform
them in a new user and network namespace.
Reject the all-zeros address in vxlan_mdb_is_valid_source(), which covers
both call sites. A (*, G) entry is expressed by omitting the source, so
nothing legitimate is refused.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
Fixes: a3a48de5ea ("vxlan: mdb: Add MDB control path support")
Signed-off-by: Baul Lee <baul.lee@xbow.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260826173604.90158-1-baul.lee@xbow.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
SCTP chunks always include a four-byte generic header, but
sctp_inq_pop() currently accepts shorter declared lengths. A zero-length
chunk leaves chunk_end at the current header.
When ASCONF is covered by the association's SCTP-AUTH policy,
sctp_assoc_bh_rcv() can continue before the state machine performs its
normal chunk-length check. sctp_inq_pop() then returns the same malformed
chunk repeatedly and the receive softirq can lock up.
A remote SCTP peer can trigger this after establishing an association on
a kernel built with CONFIG_IP_SCTP and configured with
net.sctp.addip_enable=1 and net.sctp.auth_enable=1. The reproducer did
not require application credentials, a shared SCTP AUTH key, or
net.sctp.addip_noauth_enable=1.
On commit f967455fb2 ("seg6: reset IP6CB after IPv6 decapsulation"),
one zero-length ASCONF caused repeated
watchdog soft-lockup reports in a two-vCPU KVM guest. All 3 pre-trigger
health probes succeeded, while 36 of 37 post-trigger probes failed. With
this change, all 37 post-trigger probes succeeded and no equivalent
soft-lockup signature appeared.
Reject chunks shorter than the generic SCTP header at the shared inqueue
parser boundary. Mark the packet for discard before either caller can
continue processing it, while preserving the four-byte generic minimum.
Declared-length 1 through 4 controls and kernel-generated ASCONF traffic
remained healthy. The patched sctp_hello selftest passed for IPv4 and
IPv6.
The complete private reproducer and validation evidence are available
directly to maintainers on request.
Fixes: bbd0d59809 ("[SCTP]: Implement the receive and verification of AUTH chunk")
Cc: stable@vger.kernel.org
Signed-off-by: Charles Vosburgh <theminershive@gmail.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260827-sctp-zero-chunk-inqueue-v2-1-2e7669c6a6cb@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
amd-xgbe driver currently sets the MAC_RCR.DCRCC bit whenever
RX is enabled. This disables hardware FCS validation, causing packets
with bad FCS to be accepted unconditionally.
This change unsets DCRCC so that packets with bad FCS will be dropped,
in-line with typical behaviours of many other network controllers.
Tests:
- Verified that packets with bad FCS are now dropped.
- Verified that receiving packets with bad FCS will increment the
`rx_crc_errors` counter.
Fixes: c5aa9e3b81 ("amd-xgbe: Initial AMD 10GbE platform driver")
Signed-off-by: James Nugraha <aslan.jnn@gmail.com>
Link: https://patch.msgid.link/20260827232220.69907-1-aslan.jnn@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
raw_v4_match() reads inet_daddr, inet_rcv_saddr and
sk_bound_dev_if locklessly under RCU. Bind and connect writers are
annotated, but __udp_disconnect() still clears the same fields using
plain stores.
Commit 18f116931f ("raw: annotate lockless match fields in
raw_v4_match()") added the lockless readers and annotated the raw bind
and datagram connect writers. Its v4 revision intentionally left the
shared disconnect-side IPv4 writers for follow-up cleanup.
Complete that follow-up by using WRITE_ONCE() for the disconnect-side
stores, including the inet_rcv_saddr reset in inet_reset_saddr(), to
pair with the lockless raw socket matcher.
Fixes: 0daf07e527 ("raw: convert raw sockets to RCU")
Link: https://lore.kernel.org/netdev/20260716142958.3064224-1-runyu.xiao@seu.edu.cn/
Suggested-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260828012918.1461-1-xuanqiang.luo@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sctp_verify_asconf() walks ASCONF-ACK parameters with
sctp_walk_params(), which advances by SCTP_PAD4(length), while the
consumer sctp_get_asconf_response() iterates the same parameters
advancing by the raw length, without padding. A single odd-length
parameter desynchronises the two walks and makes the consumer
interpret attacker-controlled bytes at a misaligned offset.
When those bytes yield a length of zero, the while loop over
asconf_ack_len makes no progress, spinning forever in softirq
context, and the watchdog reports a soft lockup. All reads stay
within the received skb, so the lockup is a pure remote denial of
service. A remote peer can trigger it with a crafted ASCONF-ACK on
an ADD-IP enabled association with an outstanding ASCONF (RFC 5061
section 4.1.2 requires the chunk to be authenticated, but the
predefined empty key id 0 allows the peer to compute the same
association HMAC from publicly exchanged parameters, so the gate
does not help).
The SCTP_PARAM_ERR_CAUSE case of sctp_verify_asconf() also performs
no length check, letting a parameter without a complete error
header reach the consumer, which reads errhdr.cause past the end of
the parameter, an out-of-bounds read.
Reject SCTP_PARAM_ERR_CAUSE parameters shorter than
sizeof(struct sctp_addip_param) + sizeof(struct sctp_errhdr) at the
verifier, and advance the consumer iterator with the same padding
rule as the verifier to keep the two walks in lockstep. The verifier
change guarantees a complete error header in every ERR_CAUSE
parameter the consumer can see, so the consumer's asconf_ack_len
check is dropped and it returns err_param->cause directly. The
consumer padding fix is still required because odd lengths remain
valid for SCTP_PARAM_ERR_CAUSE per RFC 5061.
The issue was found by ZeroHive, a vulnerability hunting agent at
Tencent Yunding Lab.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260828042431.3873725-1-bsdhenrymartin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The SCTP_CMD_TIMER_START handler checks timer_pending() before calling
timer_reduce(). The timer can expire and detach between these operations,
causing timer_reduce() to rearm the timer without taking the association
reference required for the newly armed timer.
The timer callback later unconditionally drops its association reference,
which can leave the association reference count unbalanced and result in
use-after-free during association teardown.
Use the return value of timer_reduce() to determine whether the timer was
actually armed. Take the association reference only when timer_reduce()
successfully starts a new timer, closing the race between checking the
timer state and rearming it.
This issue was reported by Nico Yip (@_cyeaa_) working with TrendAI Zero
Day Initiative.
Fixes: 20a785aa52 ("sctp: Don't add the shutdown timer if its already been added")
Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/9d8f1b5c50329d5ea7c642128d35681abaa9ed20.1787773744.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cen Zhang says:
====================
tcp: fix use-after-free in do_tcp_getsockopt()
do_tcp_getsockopt() has two lockless reads of icsk_ca_ops. Since BPF
struct_ops congestion control made icsk_ca_ops point to dynamically
allocated memory, a concurrent setsockopt(TCP_CONGESTION) can replace
the pointer and free the old object while either reader is using it.
Patch 1 fixes the TCP_CONGESTION path by copying ca_ops->name to a
stack buffer while holding rcu_read_lock(). It also uses READ_ONCE()
for the lockless load and annotates the relevant icsk_ca_ops stores
with WRITE_ONCE().
Patch 2 fixes the TCP_CC_INFO path by keeping the READ_ONCE() load,
ca_ops->get_info lookup, and call inside an RCU read-side critical
section.
====================
Link: https://patch.msgid.link/cover.1787870710.git.blbllhy@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
do_tcp_getsockopt() reads icsk->icsk_ca_ops and dereferences the
get_info function pointer without rcu_read_lock(). With BPF struct_ops
congestion control, ca_ops can point to dynamically allocated memory
that is freed concurrently, resulting in a use-after-free when the
kernel dereferences or calls through the stale pointer.
BUG: KASAN: slab-use-after-free in do_tcp_getsockopt+0x2037/0x23e0
Read of size 8 at addr ffff888013701258 by task exploit/149
do_tcp_getsockopt+0x2037/0x23e0 (net/ipv4/tcp.c:4564)
tcp_getsockopt+0x91/0xf0
__sys_getsockopt+0xf7/0x170
Fix this by wrapping the ca_ops load and get_info call within
rcu_read_lock()/rcu_read_unlock(), and using READ_ONCE() to load
the icsk_ca_ops pointer.
Fixes: 0baf26b0fc ("bpf: tcp: Support tcp_congestion_ops in bpf")
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: AutonomousCodeSecurity@microsoft.com
Cc: stable@vger.kernel.org
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) <blbllhy@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/65fd3816ed5d541d9edd4bf4fcf97104a2cf907a.1787870710.git.blbllhy@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
