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v7.2
4289 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Jamal Hadi Salim
|
120977e2c0 |
net/sched: cls_bpf: reject dev-bound programs bound to a different device
cls_bpf_prog_from_efd() obtained a SCHED_CLS program via
bpf_prog_get_type_dev() but never verified that a device-bound (offloaded)
program's bound netdev matches the TC netdev the classifier is being
attached to. This let a program loaded with prog_ifindex for device A be
attached via cls_bpf + skip_sw to device B; deleting device A then
destroyed the program's offload state while it was still attached to
device B, triggering a netdevsim WARN (panic with panic_on_warn=1).
Mirror the XDP attach path (net/core/dev.c) and reject the attach with
-EINVAL when a dev-bound program's bound device does not match the
target device.
Fixes:
|
||
|
Zhang Changzhong
|
6d3724e616 |
net/sched: cls_u32: skip hash tables in u32_bind_class()
u32_walk() enumerates both struct tc_u_hnode and struct tc_u_knode
through the walker callback. u32_bind_class() unconditionally casts the
passed fh to tc_u_knode and accesses &n->res, so when fh is actually a
tc_u_hnode, which has no tcf_result member, this results in a
slab-out-of-bounds read of res->classid in tc_cls_bind_class().
The issue can be reproduced with the following commands:
tc qdisc add dev lo root handle 1: hfsc
tc class add dev lo parent 1: classid 1:1 hfsc sc rate 1000kbit
tc filter add dev lo parent 1:1 protocol ip prio 1 u32 match u32 0 0 flowid 1:1
tc class add dev lo parent 1: classid 1:2 hfsc sc rate 2000kbit
Fix this by skipping hash tables via the TC_U32_KEY(handle) check.
Fixes:
|
||
|
Jamal Hadi Salim
|
f60b396ee1 |
net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain
tcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking
rcu_access_pointer(a->goto_chain) and then calling
tcf_action_goto_chain_exec(), which does a second, independent
rcu_dereference_bh(a->goto_chain) read and immediately dereferences
chain->filter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact
replace path) can clear a->goto_chain between the two reads, so the second
read returns NULL and tcf_action_goto_chain_exec() dereferences NULL.
Fix the race by doing a single rcu_dereference_bh() read of a->goto_chain
in tcf_action_exec(), checking it once for NULL, and passing the resulting
chain pointer into tcf_action_goto_chain_exec(). This turns the split
check/use into a single check/use on one value.
Fixes:
|
||
|
Hyunjung Ko
|
8a7ed56167 |
net/sched: act_ct: fix sk_buff leak when the header checks reject a packet
tcf_ct_handle_fragments() runs its header sanity checks before handing
anything to the defragmentation engine:
if (family == NFPROTO_IPV4)
err = tcf_ct_ipv4_is_fragment(skb, &frag);
else
err = tcf_ct_ipv6_is_fragment(skb, &frag);
if (err || !frag)
return err;
tcf_ct_ipv4_is_fragment() returns -EINVAL or -ENOMEM;
tcf_ct_ipv6_is_fragment() adds -EPROTO when ipv6_find_hdr() fails. None of
them frees or queues the skb, so on that path the caller still owns it.
tcf_ct_act() however funnels every non-zero return into the
ownership-transfer exit:
err = tcf_ct_handle_fragments(net, skb, family, p->zone, &defrag);
if (err)
goto out_frag;
...
out_frag:
if (err != -EINPROGRESS)
tcf_action_inc_drop_qstats(&c->common);
return TC_ACT_CONSUMED;
TC_ACT_CONSUMED means the action took ownership of the skb, so no caller
frees it - sch_handle_ingress(), sch_handle_egress() and
tcf_qevent_handle() all deliberately skip the free for that verdict. The
skb is therefore orphaned: one sk_buff plus its data buffer is leaked per
malformed packet, unbounded. Note the drop counter is already incremented
for these errors, so the statistics claim a drop that never happens.
Three different ownership states reach out_frag: today - the skb may be
queued by the defrag engine (-EINPROGRESS), already freed by
nf_ct_handle_fragments(), or still owned by us. Tell the caller which of
those it is, and free the packet ourselves in the last case, which
restores the TC_ACT_SHOT behaviour that predated the Fixes: commit.
Reproduced on v7.2-rc6 with a 54-byte frame carrying a 40-byte IPv6
header with nexthdr = 0 (hop-by-hop) and nothing after it, on a
clsact ingress chain with "action ct". kmemleak reports one leaked
232-byte skbuff_head_cache object plus its 704-byte data buffer per
packet; with this patch it reports none.
Fixes:
|
||
|
Hyunjung Ko
|
883b56ae58 |
net/sched: act_gact, act_police: range check the fallback control action
tcf_action_check_ctrlact() range checks the primary control action: if (!opcode) ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0; TC_ACT_VALUE_MAX is TC_ACT_TRAP, so kernel-internal verdicts above it cannot be set that way. But act_gact and act_police each carry a second, independent control action supplied by user space that never reaches that helper - TCA_GACT_PROB.paction and TCA_POLICE_RESULT. Both only reject TC_ACT_GOTO_CHAIN, so any other value is stored verbatim and returned verbatim from the action. In particular user space can store TC_ACT_CONSUMED, which is TC_ACT_VALUE_MAX + 1 and is deliberately not part of the UAPI value range. That verdict tells every caller the action took ownership of the skb, so nobody frees it: sch_handle_ingress(), sch_handle_egress() and tcf_qevent_handle() all deliberately skip the free for it. The result is one leaked sk_buff plus its data buffer per packet traversing the filter, unbounded, for all traffic on the chain including kernel-generated packets. Both are trivially deterministic. act_gact clamps tcfg_pval to >= 1, so with pval = 1 gact_determ() returns the fallback for every packet. act_police has no mandatory rate, so rate = 0 leaves tcfp_mtu = ~0 and tcf_police_mtu_check() always passes. TC_ACT_CONSUMED was added by commit |
||
|
Zijie Huang
|
dedd34b0f2 |
net/sched: reject overly deep qdisc hierarchies
Deep qdisc hierarchies can lead to excessive recursion in qdisc tree
walkers and exhaust the kernel stack. The existing loop check does not
cover the create-and-graft path, so a hierarchy can still be extended by
creating a new child qdisc below an already deep parent.
Store the hierarchy depth in struct Qdisc and update it when qdiscs are
grafted. Reject new child qdiscs once the parent is already at the maximum
allowed depth.
Fixes:
|
||
|
Jamal Hadi Salim
|
a347304b2c |
net/sched: cls_api: Always acquire rtnl_lock when destroying locked classifiers
Another challenge with unlocked filters.
There is a short window in tc_new_tfilter where a tcf_proto can be found
and briefly referenced by a totally unrelated, unlocked classifier's request
and cause a race.
Feng created a poc which created this race with two threads, one creating a
u32 filter and other a flower filter in the same chain/prio:
1. Both threads enter tc_new_tfilter, both find the chain empty, both
drop filter_chain_lock
2. u32 finishes tcf_proto_create("u32") first, calls
tcf_chain_tp_insert_unique() -> inserts u32_tp into the chain
3. flower finishes tcf_proto_create("flower") later, calls
tcf_chain_tp_insert_unique() -> tcf_chain_tp_find() now sees u32_tp
already there, takes a reference on it, destroys flower's own tp_new
and returns u32_tp to the caller.
Flower then hits the kind mismatch check (because it requested for kind
"flower" but tp->ops->kind is "u32") and goes through the errout path
which calls tcf_proto_put() on u32_tp. If the u32 thread has already
gone through its own errout (its change() call failed on the PoC's empty
options) and dropped its create and insert refs, flower's put is the
last one and drops u32_tp's refcnt to zero.
At this point tp->ops->destroy() runs in a context that never took
rtnl_lock. When that happens, it might cause a UAF like the following
(illustrated by the PoC):
[ +0.000710] BUG: KASAN: slab-use-after-free in u32_init (net/sched/cls_u32.c:393)
[ +0.000281] Read of size 8 at addr ffff888120022f00 by task poc_feng_xue/524
Call Trace:
u32_init (net/sched/cls_u32.c:393)
tc_new_tfilter (net/sched/cls_api.c:2378)
Allocated by task 526:
u32_init (net/sched/cls_u32.c:378)
tc_new_tfilter (net/sched/cls_api.c:2378)
Freed by task 522:
kfree
u32_destroy (net/sched/cls_u32.c:662)
tcf_proto_destroy (net/sched/cls_api.c:446)
tcf_proto_put (net/sched/cls_api.c:459)
tc_new_tfilter (net/sched/cls_api.c:2459)
Fix this by having tcf_proto_destroy() take rtnl_lock around
tp->ops->destroy() for locked classifiers whenever rtnl is not held.
To explain why I used a temp variable "not_lockless" I'd like to point to a
semi-related note on rtnl_held vs TCF_PROTO_OPS_DOIT_UNLOCKED (adding here
for future cleanup if deemed necessary):
The rtnl_held parameter and the TCF_PROTO_OPS_DOIT_UNLOCKED flag are
redundant sources of truth for whether rtnl_lock is held. Among the nine
classifier destroy(..rtnl_held..) callbacks, only flower consults the
rtnl_held parameter which it propagates to tc_setup_cb_destroy()
and tc_setup_cb_call(). The other eight (u32, flow, bpf, cgroup, route, basic,
fw, mall) ignore it entirely;-> those that call tc_setup_cb_destroy()
(u32, bpf, mall) hardcode true always instead of forwarding the parameter.
A future cleanup should remove the rtnl_held parameter from the destroy callback
signature entirely and have callers rely solely on their knowledge whether
they are running in an unlocked context.
Fixes:
|
||
|
Toke Høiland-Jørgensen
|
2a33516f9e |
net/sched: sch_cake: drop WARN_ON(1) for malformed packets in ACK filter
The sch_cake ACK filter parses packets to find the TCP header and filter
duplicated ACKs if the flow is backlogged. The parsing code contains a
WARN_ON(1) which can be triggered by a malformed IP header in certain
cases. Depending on the system configuration, this leads either to
either spamming dmesg with warnings, or a panic if panic_on_warn is set.
The code already correctly skips the offending packet in the branch that
triggers the warning, so the WARN_ON itself doesn't really serve any
purpose. So just drop it altogether to avoid the inconvenient side
effects.
Fixes:
|
||
|
Jamal Hadi Salim
|
47d7f70512 |
net/sched: cls_route: fix fastmap use-after-free on filter
The route4 classifier maintains a 16-slot fastmap cache that stores raw
struct route4_filter pointers indexed by (id, iif). The reader
(route4_classify) populates this cache via route4_set_fastmap() for every
classified packet that hits a filter. The writer (route4_delete,
route4_change) clears the cache via route4_reset_fastmap() before
RCU-deferred kfree of the filter.
This creates a UAF race:
1. Reader walks the RCU-protected bucket chain, finds filter f
2. Writer unlinks f, calls route4_reset_fastmap(), then tcf_queue_work()
3. Reader calls route4_set_fastmap() and writes f into the cache
*after* the writer's reset, caching a pointer about to be freed
4. After the RCU grace period, kfree(f) executes
5. Next classified packet on the same (id, iif) tuple hits the stale
fastmap entry and reads f->res from freed memory
Reproduced with an mdelay(100) accelerator in route4_set_fastmap() and a
concurrent add/delete stress test (provided by both zdi and Santosh).
Both triggered KASAN slab-use-after-free reports in the route4 fastmap
paths.
Fix:
Introduce a per-filter boolean dying flag to suppress stale fastmap
republishing by in-flight readers.
Fixes:
|
||
|
Cen Zhang (Microsoft)
|
aef96eead2 |
net/sched: cls_u32: validate offshift to prevent shift-out-of-bounds
u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char,
0-255) into the kernel knode object without bounds validation. When a
packet later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates
`ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit
value promoted to a 32-bit int. Any offshift >= 32 is undefined behavior
per C11 6.5.7p3, triggerable by an unprivileged user via user/network
namespaces.
UBSAN: shift-out-of-bounds in net/sched/cls_u32.c:236:43
shift exponent 32 is too large for 32-bit type int
Fix this by rejecting offshift >= 16 during filter creation in
u32_change().
Fixes:
|
||
|
Jonas Köppeler
|
a3729e0df0 |
net/sched: sch_cake: skip clearing unused tins during rate adjustment
When cake_configure_rates() is called from the dequeue path with
rate_adjust=true, it only needs to update the rate parameters. The
loop that clears the unused tins is both unnecessary and harmful in
this path:
- cake_clear_tin() overwrites q->cur_tin and q->cur_flow, which are
actively used by cake_dequeue(), corrupting the dequeue state.
- iterating over the unused tins and their internal queues to purge
packets adds needless overhead to the hot path.
Skip the entire loop when rate_adjust is set, as neither
cake_clear_tin() nor the mtu_time update are needed when only the
rate changes.
The clearing loop runs on every rate adjustment from the dequeue path,
clearing (max_tins - cur_tins) tins each time, so the cost grows the
fewer tins the configured mode actually uses. Testing cake_mq over veth
(8 rx/tx queues, 2 Gbit limit) with flent's [1] rrul and tcp_nup tests and
32 TCP upstreams shows a large drop in loaded latency and a throughput
gain, restoring behaviour to pre-15c2715a5264 levels:
+------------+------+------+-------+-------+---------+
| kernel | mode | test | base | load | tput |
| | | | (ms) | (ms) | (Mbit) |
+------------+------+------+-------+-------+---------+
| net-next | be | rrul | 0.810 | 11.78 | 1469.67 |
| net-next | be | nup | 0.637 | 85.71 | 1243.15 |
| net-next | ds3 | rrul | 0.397 | 15.28 | 1770.06 |
| net-next | ds3 | nup | 0.351 | 15.98 | 1799.39 |
+------------+------+------+-------+-------+---------+
| patched | be | rrul | 0.092 | 0.56 | 1873.40 |
| patched | be | nup | 0.109 | 1.82 | 1869.12 |
| patched | ds3 | rrul | 0.097 | 0.98 | 1866.10 |
| patched | ds3 | nup | 0.101 | 0.51 | 1861.79 |
+------------+------+------+-------+-------+---------+
The same trend holds on real hardware (IPQ8074A, 4 rx/tx queues,
OpenWrt): in besteffort mode the tcp_nup loaded latency drops from
~470 ms to ~4 ms.
[1] https://flent.org
Fixes:
|
||
|
Aldo Ariel Panzardo
|
f43ee0c073 |
net/sched: serialize qdisc_rtab_list against concurrent get/put
qdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly
linked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no
lock. This was only safe because every caller historically held the RTNL
mutex, which serialized all rate-table lookups, inserts and frees.
That invariant no longer holds. cls_flower sets
TCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false
for it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through
tcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->
tcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the
RTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each
adding a flower filter with a police action carrying the same rate, then
race on qdisc_rtab_list and on the non-atomic refcnt, leading to a
use-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.
qdisc_rtab_list is a single global (not per-netns), so the corrupted
object is shared system-wide.
BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160
qdisc_put_rtab+0x12f/0x160
tcf_police_init+0xda9/0x1590
tcf_action_init_1+0x460/0x6b0
tcf_action_init+0x439/0xa40
tcf_exts_validate_ex+0x42d/0x550
fl_change+0xddd/0x7da0
tc_new_tfilter+0xaa7/0x2420
rtnetlink_rcv_msg+0x95e/0xe90
which belongs to the cache kmalloc-2k of size 2048
Protect qdisc_rtab_list and the refcount with a dedicated spinlock. The
(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before
taking the lock; if a concurrent inserter added an identical table in the
meantime the freshly allocated one is freed under the lock, so no
duplicate is leaked. qdisc_put_rtab() now decrements the refcount and
unlinks under the same lock.
Fixes:
|
||
|
Jamal Hadi Salim
|
ec48b3be2c |
net/sched: Handle TC_ACT_REDIRECT from qdisc filter chains
When a TC filter attached to a qdisc filter chain returns TC_ACT_REDIRECT (ex: via an eBPF program calling bpf_redirect() or an act_bpf action), the redirect was silently lost i.e no qdisc classify function handled TC_ACT_REDIRECT, so the packet fell through the switch and was enqueued normally instead of being redirected. This has been broken since bpf_redirect() was introduced for TC in commit |
||
|
Daniel Borkmann
|
3f4920d165 |
bpf: Reject redirect helpers without a bpf_net_context
The bpf_redirect*() helpers and skb_do_redirect() obtain the per-task
bpf_redirect_info via bpf_net_ctx_get_ri(), which dereferences the
current->bpf_net_context unconditionally. That context is established
on the paths that run tc BPF such as sch_handle_{ingress,egress}(),
*except* for the case where {cls,act}_bpf was attached to a proper
qdisc. A program running from there reaches the NULL deref in two ways:
* It calls bpf_redirect() directly, which dereferences the context at
the top of the helper:
tc qdisc add dev eth0 root handle 1: red limit 1MB min 10KB max 20KB \
avpkt 1000 burst 100 qevent early_drop block 10
tc filter add block 10 pref 1 bpf obj redirect.o
* It simply returns TC_ACT_REDIRECT without helper call: tcf_qevent_handle()
then dispatches to skb_do_redirect(), which dereferences the context
Rather than extending bpf_net_context management into the qdisc path,
make the redirect helpers refuse to operate when no context exists, and
have tcf_qevent_handle() drop a TC_ACT_REDIRECT verdict instead of
calling skb_do_redirect(). Previous behaviour was a crash, so nothing
regresses by not supporting it.
Fixes:
|
||
|
Jamal Hadi Salim
|
f1f5c8a395 |
net/sched: act_tunnel_key: Defer dst_release to RCU callback
Fix a race-condition use-after-free in tunnel_key_release_params().
The function releases the metadata_dst of the old params synchronously
via dst_release() while deferring the params struct free with
kfree_rcu(). A concurrent tunnel_key_act() reader on the datapath may
still hold the old params pointer (under rcu_read_lock_bh) and proceed
to call dst_clone(¶ms->tcft_enc_metadata->dst) after the writer's
dst_release has already pushed the dst's rcuref to RCUREF_DEAD.
zdi-disclosures@trendmicro.com produced a poc which i (and Victor) verified
that KASAN reports:
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112
BUG: KASAN: slab-use-after-free in atomic_sub_return_release include/linux/atomic/atomic-instrumented.h:326
BUG: KASAN: slab-use-after-free in __rcuref_put include/linux/rcuref.h:109
BUG: KASAN: slab-use-after-free in rcuref_put include/linux/rcuref.h:173
BUG: KASAN: slab-use-after-free in dst_release+0x5b/0x370 net/core/dst.c:168
Write of size 4 at addr ffff88806158de40 by task poc/9388
CPU: 0 UID: 0 PID: 9388 Comm: poc Tainted: G W 7.1.0-rc7 #7 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378
print_report+0x139/0x4ad mm/kasan/report.c:482
kasan_report+0xe4/0x1d0 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:186
kasan_check_range+0x125/0x200 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:112
atomic_sub_return_release include/linux/atomic/atomic-instrumented.h:326
__rcuref_put include/linux/rcuref.h:109
rcuref_put include/linux/rcuref.h:173
dst_release+0x5b/0x370 net/core/dst.c:168
refdst_drop include/net/dst.h:272
skb_dst_drop include/net/dst.h:284
skb_release_head_state+0x293/0x400 net/core/skbuff.c:1163
skb_release_all net/core/skbuff.c:1187
[..]
Allocated by task 9391:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398
__kasan_kmalloc+0x9a/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263
__do_kmalloc_node mm/slub.c:5296
__kmalloc_noprof+0x2f1/0x830 mm/slub.c:5308
kmalloc_noprof include/linux/slab.h:954
kzalloc_noprof include/linux/slab.h:1188
offload_action_alloc+0x2f/0x130 net/core/flow_offload.c:35
tcf_action_offload_add_ex+0x1ba/0x880 net/sched/act_api.c:258
tcf_action_offload_add net/sched/act_api.c:293
tcf_action_init+0x66e/0xa20 net/sched/act_api.c:1547
tcf_action_add+0xf6/0x5d0 net/sched/act_api.c:2101
[..]
Freed by task 9391:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253
__kasan_slab_free+0x6b/0x90 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235
slab_free_hook mm/slub.c:2689
slab_free mm/slub.c:6251
kfree+0x21f/0x6b0 mm/slub.c:6566
tcf_action_offload_add_ex+0x4ad/0x880 net/sched/act_api.c:284
tcf_action_offload_add net/sched/act_api.c:293
tcf_action_init+0x66e/0xa20 net/sched/act_api.c:1547
tcf_action_add+0xf6/0x5d0 net/sched/act_api.c:2101
The buggy address belongs to the object at ffff88806158de00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 64 bytes inside of
freed 256-byte region [ffff88806158de00, ffff88806158df00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88806158d600 pfn:0x6158c
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000240 ffff88801c841b40 ffffea0001856290 ffffea0001856190
raw: ffff88806158d600 0000000800100009 00000000f5000000 0000000000000000
head: 04fff00000000240 ffff88801c841b40 ffffea0001856290 ffffea0001856190
head: ffff88806158d600 0000000800100009 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9391, tgid 9378 (poc), ts 123227323196, free_ts 0
set_page_owner include/linux/page_owner.h:32
post_alloc_hook+0xfe/0x140 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861
get_page_from_freelist+0x110c/0x2fc0 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x263/0x2bc0 mm/page_alloc.c:5221
alloc_slab_page mm/slub.c:3278
allocate_slab mm/slub.c:3467
new_slab+0xa6/0x690 mm/slub.c:3525
refill_objects+0x271/0x420 mm/slub.c:7272
refill_sheaf mm/slub.c:2816
__pcs_replace_empty_main+0x373/0x630 mm/slub.c:4652
alloc_from_pcs mm/slub.c:4750
slab_alloc_node mm/slub.c:4884
__do_kmalloc_node mm/slub.c:5295
__kmalloc_noprof+0x66d/0x830 mm/slub.c:5308
kmalloc_noprof include/linux/slab.h:954
metadata_dst_alloc+0x26/0x90 net/core/dst.c:298
tun_rx_dst include/net/dst_metadata.h:144
__ip_tun_set_dst include/net/dst_metadata.h:208
tunnel_key_init+0xb01/0x1b90 net/sched/act_tunnel_key.c:451
tcf_action_init_1+0x46b/0x6c0 net/sched/act_api.c:1428
tcf_action_init+0x448/0xa20 net/sched/act_api.c:1503
tcf_action_add+0xf6/0x5d0 net/sched/act_api.c:2101
[..]
==================================================================
Fix by moving dst_release() into a custom RCU callback that runs
after the grace period, matching the lifetime of the containing
params struct. Readers in the datapath therefore always find a live
rcuref when calling dst_clone().
Fixes:
|
||
|
Samuel Moelius
|
b7f97cae7e |
net/sched: cake: reject overhead values that underflow length
CAKE accepts signed overhead values and stores them in an s16, but the
adjusted packet length calculation uses unsigned arithmetic. A negative
effective length can therefore wrap to a large value.
Such configurations make rate accounting depend on integer wraparound
rather than on the packet size userspace intended to model. A static
netlink lower bound is not enough because packets reaching CAKE can be
smaller than any reasonable manual-overhead allowance.
Fold the signed overhead adjustment into the existing datapath MPU clamp
so negative adjusted lengths are clamped before link-layer framing
adjustments.
Fixes:
|
||
|
Jamal Hadi Salim
|
8b519cbcab |
net/sched: act_pedit: fix TOCTOU heap OOB write in tc offload
There is a TOCTOU race condition in flower lockless approach between sizing
a flow_rule buffer and filling it.
zdi-disclosures@trendmicro.com reports:
The cls_flower classifier operates with TCF_PROTO_OPS_DOIT_UNLOCKED
(fl_change runs without RTNL), while RTM_NEWACTION holds RTNL, so the
independent locking domains make the race reachable in practice. KASAN
confirms:
BUG: KASAN: slab-out-of-bounds in tcf_pedit_offload_act_setup+0x81b/0x930
Write of size 4 at addr ffff888001f27520 by task poc-toctou/312
The buggy address is located 0 bytes to the right of
allocated 288-byte region [ffff888001f27400, ffff888001f27520)
(cache kmalloc-512)
Note: The result is a heap OOB write attacker-controlled content into the
adjacent slab object (requires CAP_NET_ADMIN).
The fix introduces reading tcfp_nkeys under act->tcfa_lock in all places
using a new tcf_pedit_nkeys_locked() which replaces the old tcf_pedit_nkeys().
Additionally we close the remaining TOCTOU window between the sizing read and
the fill reads by more careful accounting.
Rather than silently truncating the key count, which leads to incorrect
action semantics offloaded to hardware and secondary OOB writes if
the remaining capacity is zero or consumed by prior actions, we enforce
remaining capacity checks and return -ENOSPC if the required space exceeds
the remaining capacity.
Fixes:
|
||
|
Jamal Hadi Salim
|
6301f6a34e |
net/sched: sch_teql: move rcu_read_lock()/spin_lock() from _bh variants
This is a followup based on sashiko comments [1] on commit |
||
|
Samuel Moelius
|
a225f8c207 |
net/sched: hhf: clear heavy-hitter state on reset
HHF reset does not clear the classifier state used to identify heavy
hitters. Packets after reset can therefore be scheduled using flow
history from before the reset.
The reset operation should return the qdisc to an empty state.
Clear the heavy-hitter classifier tables when HHF is reset.
Fixes:
|
||
|
Samuel Moelius
|
bf83ee4587 |
net/sched: dualpi2: clear stale classification on filter miss
DualPI2 leaves previous classification state attached to an skb when
filter classification returns no match. The enqueue path can then act
on stale state from an earlier classification attempt.
A filter miss should fall back to the default class without reusing old
per-packet classification data.
Initialize the classification result to CLASSIC before running the
classifier. Explicit L4S, priority, and successful filter
classification can still override that default.
Fixes:
|
||
|
Sechang Lim
|
adc49c7ba6 |
net/sched: act_bpf: use rcu_dereference_bh() to read the filter
tcf_bpf_act() can run from the tc egress path, which holds only
rcu_read_lock_bh(), but reads prog->filter with rcu_dereference() and
trips lockdep:
WARNING: suspicious RCU usage
net/sched/act_bpf.c:47 suspicious rcu_dereference_check() usage!
1 lock held by syz.2.1588/12756:
#0: (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit net/core/dev.c:4792
tcf_bpf_act+0x6ae/0x940 net/sched/act_bpf.c:47
tcf_classify+0x6e4/0x1080 net/sched/cls_api.c:1860
sch_handle_egress net/core/dev.c:4545 [inline]
__dev_queue_xmit+0x2185/0x2c00 net/core/dev.c:4808
packet_sendmsg+0x3dfa/0x5120 net/packet/af_packet.c:3114
The other tc actions and cls_bpf already use rcu_dereference_bh() here.
Do the same.
Fixes:
|
||
|
Jamal Hadi Salim
|
e5b811fe79 |
net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF
The teql master->slaves singly linked list is not protected against
multiple writes. It can be mod'ed concurently from teql_master_xmit(),
teql_dequeue(), teql_init() and teql_destroy() without holding any list
lock or RCU protection.
zdi-disclosures@trendmicro.com has demonstrated that the qdisc is freed
after an RCU grace period, but teql_master_xmit() running on another
CPU can still hold a stale pointer into the list, resulting in a
slab-use-after-free:
BUG: KASAN: slab-use-after-free in teql_master_xmit+0xf0f/0x16b0
Read of size 8 at addr ffff888013fb0440 by task poc/332
Freed 512-byte region [ffff888013fb0400, ffff888013fb0600) (kmalloc-512)
The fix?
Add a per-master slaves_lock spinlock that serializes all mutations of
master->slaves and the NEXT_SLAVE() links in teql_destroy() and
teql_qdisc_init(). teql_master_xmit() also takes the same slaves_lock
around those updates.
Annotate master->slaves and the per-slave ->next pointer with __rcu and
use the appropriate RCU accessors everywhere they are touched:
rcu_assign_pointer() on the writer side (under slaves_lock),
rcu_dereference_protected() for the writer-side loads (also under
slaves_lock), rcu_dereference_bh() for the loads in teql_master_xmit() and
rtnl_dereference() for the loads in teql_master_open()/teql_master_mtu(),
which run under RTNL.
Pair this with rcu_read_lock_bh()/rcu_read_unlock_bh() around the list
traversal in teql_master_xmit(), so that readers either observe a fully
linked list or are deferred until the in-flight mutation completes. The two
early-return paths in teql_master_xmit() are updated to release the RCU-bh
read-side critical section before returning, since leaving it held would
disable BH on that CPU for good.
Fixes:
|
||
|
Bryam Vargas
|
54f6b0c843 |
net/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked
multiq_dequeue() takes a packet from a band's child with a direct
->dequeue() call after multiq_peek() peeked it. When the child is
non-work-conserving the peek stashes the skb in the child's gso_skb, so
the direct dequeue returns a different skb and orphans the stash,
desyncing the child's qlen/backlog. With a qfq child reached through a
peeking parent (e.g. tbf) this re-enters the child on an emptied list and
dereferences NULL, panicking the kernel from softirq on ordinary egress.
Take the packet through qdisc_dequeue_peeked(), as sch_prio already does
and as sch_red and sch_sfb were just fixed to do. The helper is a no-op
when the child has no stash, so a work-conserving child is unaffected.
Fixes:
|
||
|
Bryam Vargas
|
e056e1dfcd |
net/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked
When taprio's software path peeks a non-work-conserving child qdisc, the
child stashes the peeked skb in its gso_skb; taprio_dequeue_from_txq()
then takes the packet with a direct child ->dequeue() call, which ignores
that stash, orphans the peeked skb and desyncs the child's qlen/backlog.
With a qfq child this re-enters the child on an emptied list and
dereferences NULL, panicking the kernel from softirq on ordinary egress.
Take the packet through qdisc_dequeue_peeked(), as sch_red and sch_sfb
now do. The helper returns the child's stashed skb first and is a no-op
when there is none, so a work-conserving child is unaffected and the
gated path now consumes the skb whose length was charged to the budget.
Fixes:
|
||
|
Jamal Hadi Salim
|
a8a02897f2 |
net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle
tcf_classify() can return TC_ACT_CONSUMED while the skb is held by the
defragmentation engine (e.g. act_ct on out-of-order fragments). When
that happens the skb is no longer owned by the caller and must not be
touched again.
tcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the
switch and returned the skb to the caller as if classification had
passed. The only qdisc that wires up qevents today is RED, via three call sites
(qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop)
red_enqueue() was continuing to operate on an skb it no longer owns in this
case -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF.
tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10
tc filter add block 10 ... action ct
(with ct defrag enabled and traffic that produces out-of-order
fragments, e.g. a fragmented UDP stream)
Handle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress
and egress fast paths do: treat it as stolen and return NULL without
touching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be
dropped/freed here, as it is no longer owned by us.
Fixes:
|
||
|
Eric Dumazet
|
d09a78a2a4 |
net: do not acquire dev->tx_global_lock in netdev_watchdog_up()
Marek Szyprowski reported a deadlock during system resume when virtio_net
driver is used.
The deadlock occurs because netif_device_attach() is called while holding
dev->tx_global_lock (via netif_tx_lock_bh() in virtnet_restore_up()).
netif_device_attach() calls __netdev_watchdog_up(), which now also tries
to acquire dev->tx_global_lock to synchronize with dev_watchdog().
This recursive lock acquisition results in a deadlock.
Fix this by removing the tx_global_lock acquisition from netdev_watchdog_up().
The critical state (watchdog_timer and watchdog_ref_held) is already
protected by dev->watchdog_lock, which was introduced in the blamed commit.
Fixes:
|
||
|
Xingquan Liu
|
05ed733b65 |
net/sched: dualpi2: fix GSO backlog accounting
When DualPI2 splits a GSO skb into N segments, it propagates N
additional packets to its parent before returning NET_XMIT_SUCCESS.
The parent then accounts for the original skb once more, leaving its
qlen one larger than the number of packets actually queued.
With QFQ as the parent, after all real packets are dequeued, QFQ still
has a non-zero qlen while its in-service aggregate has no active
classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes
the result to qfq_peek_skb(), causing a NULL pointer dereference.
Follow the same pattern used by tbf_segment() and taprio: count only
successfully queued segments, propagate the difference between the
original skb and those segments, and return NET_XMIT_SUCCESS whenever
at least one segment was queued.
Fixes:
|
||
|
Michael Bommarito
|
16e088016f |
net/sched: act_ct: fix nf_connlabels leak on two error paths
tcf_ct_fill_params() calls nf_connlabels_get() (setting put_labels) when
TCA_CT_LABELS is present, but two later error sites use a bare return
instead of "goto err", skipping the err: nf_connlabels_put() cleanup.
They also precede the "p->put_labels = put_labels" assignment, so the
tcf_ct_params_free() fallback does not release the count either. Each
failed RTM_NEWACTION on these paths leaks one nf_connlabels reference:
net->ct.labels_used is incremented and never released. The action is
reachable with CAP_NET_ADMIN over the netns, i.e. from an unprivileged
user namespace on default-userns kernels.
Impact: an unprivileged user with CAP_NET_ADMIN over a network namespace
(e.g. via user namespaces) leaks one nf_connlabels reference per failed
RTM_NEWACTION on the two error paths; net->ct.labels_used is never
released.
The err: label is safe to reach from both sites: p->tmpl is still NULL
there (kzalloc'd, not yet assigned) and nf_ct_put(NULL) is a no-op, so
no inline release is needed.
Fixes:
|
||
|
Zihan Xi
|
9092e15def |
net/sched: act_ct: preserve tc_skb_cb across defragmentation
tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving
and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases
the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through
act_ct therefore loses qdisc metadata such as pkt_segs and can trigger
WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled.
Save and restore the full tc_skb_cb around nf_ct_handle_fragments(),
matching the pattern used by ovs_ct_handle_fragments().
Fixes:
|
||
|
Jakub Kicinski
|
d755d45bc0 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes in preparation for the net-next PR. Conflicts: net/tls/tls_sw.c |
||
|
Alice Mikityanska
|
9bcb30b389 |
net/sched: act_csum: don't mangle UDP tunnel GSO packets
Similar to commit
|
||
|
Victor Nogueira
|
ee1ba0add3 |
net/sched: sch_dualpi2: Add missing module alias
When a qdisc is added by name, the kernel tries to autoload its module
via request_qdisc_module(), which calls:
request_module(NET_SCH_ALIAS_PREFIX "%s", name);
i.e. it asks modprobe to resolve the "net-sch-<kind>" alias (e.g.
"net-sch-dualpi2") rather than the module's file name. Since dualpi2
was shipped without this alias, the autoload fails:
tc qdisc add dev lo root handle 1: dualpi2
Error: Specified qdisc kind is unknown.
Fix this by adding the missing alias so the qdisc is autoloaded on demand
like the others.
Fixes:
|
||
|
Eric Dumazet
|
8eed5519e4 |
net: watchdog: fix refcount tracking races
Blamed commit converted the untracked dev_hold()/dev_put() calls
in the watchdog code to use the tracked dev_hold_track()/dev_put_track()
(which were later renamed/interfaced to netdev_hold() and netdev_put()).
By introducing dev->watchdog_dev_tracker to store the
reference tracking information without adding synchronization
between netdev_watchdog_up() and dev_watchdog(), it enabled the
race condition where this pointer could be overwritten or freed
concurrently, leading to the list corruption crash syzbot reported:
list_del corruption, ffff888114a18c00->next is NULL
kernel BUG at lib/list_debug.c:52 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 91 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound linkwatch_event
RIP: 0010:__list_del_entry_valid_or_report.cold+0x22/0x2a lib/list_debug.c:52
Call Trace:
<TASK>
__list_del_entry_valid include/linux/list.h:132 [inline]
__list_del_entry include/linux/list.h:246 [inline]
list_move_tail include/linux/list.h:341 [inline]
ref_tracker_free+0x1a7/0x6c0 lib/ref_tracker.c:329
netdev_tracker_free include/linux/netdevice.h:4491 [inline]
netdev_put include/linux/netdevice.h:4508 [inline]
netdev_put include/linux/netdevice.h:4504 [inline]
netdev_watchdog_down net/sched/sch_generic.c:600 [inline]
dev_deactivate_many+0x28c/0xfe0 net/sched/sch_generic.c:1363
dev_deactivate+0x109/0x1d0 net/sched/sch_generic.c:1397
linkwatch_do_dev net/core/link_watch.c:184 [inline]
linkwatch_do_dev+0xd3/0x120 net/core/link_watch.c:166
__linkwatch_run_queue+0x3a5/0x810 net/core/link_watch.c:240
linkwatch_event+0x8f/0xc0 net/core/link_watch.c:314
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
This patch has three coordinated parts:
1) Add dev->watchdog_lock and dev->watchdog_ref_held to serialize watchdog operations.
2) Remove netdev_watchdog_up() call from netif_carrier_on():
This ensures netdev_watchdog_up() is only called from process/BH context
(via linkwatch workqueue dev_activate()), allowing us to use
spin_lock_bh() for synchronization.
3) Synchronize watchdog up and watchdog timer:
Protect netdev_watchdog_up() with tx_global_lock and watchdog_lock.
Only allocate a new tracker in netdev_watchdog_up() if one is
not already present.
In dev_watchdog(), ensure we don't release the tracker if the
timer was rescheduled either by dev_watchdog() itself or concurrently
by netdev_watchdog_up().
Fixes:
|
||
|
Victor Nogueira
|
15cd0c93bf |
net/sched: sch_dualpi2: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
Whenever dualpi2 drops packets during peek, it calls
qdisc_tree_reduce_backlog. An issue arises because it calls
qdisc_tree_reduce_backlog before it reincrements the qlen. If qlen drops
to zero, but peek returns an skb, the parent's qlen_notify callback will be
executed even though dualpi2 still has 1 packet on the queue and, thus,
mistakenly deactivates the parent's class which leads to a null-ptr-deref:
[ 101.427314][ T599] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] SMP KASAN NOPTI
[ 101.427755][ T599] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
[ 101.428048][ T599] CPU: 2 UID: 0 PID: 599 Comm: ping Not tainted 7.1.0-rc5-00284-gbce53c430ed7 #102 PREEMPT(full)
[ 101.428400][ T599] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 101.428608][ T599] RIP: 0010:qfq_dequeue (net/sched/sch_qfq.c:1150) sch_qfq
[ 101.428821][ T599] Code: 00 fc ff df 80 3c 02 00 0f 85 46 0c 00 00 4c 8d 73 48 48 89 9d b8 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 2d 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b
All code
[ 101.429348][ T599] RSP: 0018:ffff8881110df4f0 EFLAGS: 00010216
[ 101.429541][ T599] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000
[ 101.429763][ T599] RDX: 0000000000000009 RSI: 00000024c0000000 RDI: ffff88811436c2b0
[ 101.429985][ T599] RBP: ffff88811436c000 R08: ffff88811436c280 R09: 1ffff11021277523
[ 101.430206][ T599] R10: 1ffff11021277526 R11: 1ffff11021277527 R12: 00000024c0000000
[ 101.430423][ T599] R13: ffff88811436c2b8 R14: 0000000000000048 R15: 0000000020000000
[ 101.430642][ T599] FS: 00007f61813e1c40(0000) GS:ffff8881691ef000(0000) knlGS:0000000000000000
[ 101.430913][ T599] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 101.431100][ T599] CR2: 00005651650850a8 CR3: 000000010ca0b000 CR4: 0000000000750ef0
[ 101.431320][ T599] PKRU: 55555554
[ 101.431433][ T599] Call Trace:
[ 101.431544][ T599] <TASK>
[ 101.431628][ T599] __qdisc_run (net/sched/sch_generic.c:322 net/sched/sch_generic.c:427 net/sched/sch_generic.c:445)
[ 101.431792][ T599] ? dev_qdisc_enqueue (./include/trace/events/qdisc.h:49 (discriminator 22) net/core/dev.c:4176 (discriminator 22))
[ 101.431941][ T599] __dev_queue_xmit (./include/net/pkt_sched.h:120 ./include/net/pkt_sched.h:117 net/core/dev.c:4292 net/core/dev.c:4831)
Fix this by only calling qdisc_tree_reduce_backlog in peek after the
qlen is restored.
Fixes:
|
||
|
Victor Nogueira
|
52f1da34c9 |
net/sched: sch_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
Whenever codel drops packets during peek, it calls
qdisc_tree_reduce_backlog. An issue arises because it calls
qdisc_tree_reduce_backlog before it reincrements the qlen. If qlen drops
to zero, but peek returns an skb, the parent's qlen_notify callback will
be executed even though codel still has 1 packet on the queue and, thus,
will mistakenly deactivate the parent's class causing issues like a wild
memory access when qfq has codel as a child:
[ 36.339843][ T370] Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI
[ 36.340408][ T370] KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127]
[ 36.340737][ T370] CPU: 2 UID: 0 PID: 370 Comm: tc Not tainted 7.1.0-rc5-00287-g66e13b626592 #87 PREEMPT(full)
[ 36.341113][ T370] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 36.341357][ T370] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:1029 (discriminator 2) include/linux/list.h:1043 (discriminator 2) net/sched/sch_qfq.c:1369 (discriminator 2) net/sched/sch_qfq.c:1395 (discriminator 2)) sch_qfq
[ 36.342221][ T370] RSP: 0018:ffff8881100ef370 EFLAGS: 00010216
[ 36.342422][ T370] RAX: 0000000000000000 RBX: ffff8881058a9568 RCX: dffffc0000000000
[ 36.342664][ T370] RDX: 1ffff11021064dc3 RSI: ffff888108326e00 RDI: dffffc0000000000
[ 36.342905][ T370] RBP: ffff8881058a8280 R08: dead000000000122 R09: 1bd5a00000000024
[ 36.343140][ T370] R10: fffffbfff2940329 R11: fffffbfff2940329 R12: 0000000000000000
[ 36.343383][ T370] R13: dead000000000100 R14: ffff8881058a9580 R15: ffff8881058a9578
[ 36.343631][ T370] FS: 00007fc04b0ca780(0000) GS:ffff888184fef000(0000) knlGS:0000000000000000
[ 36.343911][ T370] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 36.344116][ T370] CR2: 0000557c02c02000 CR3: 000000010e0ba000 CR4: 0000000000750ef0
[ 36.344359][ T370] PKRU: 55555554
[ 36.344481][ T370] Call Trace:
...
[ 36.345054][ T370] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1487) sch_qfq
[ 36.345222][ T370] qdisc_reset (net/sched/sch_generic.c:1057)
[ 36.345503][ T370] __qdisc_destroy (net/sched/sch_generic.c:1096)
[ 36.345677][ T370] qdisc_graft (net/sched/sch_api.c:1062 net/sched/sch_api.c:1053 net/sched/sch_api.c:1159)
[ 36.346335][ T370] tc_get_qdisc (net/sched/sch_api.c:1528 net/sched/sch_api.c:1556)
Fix this by only calling qdisc_tree_reduce_backlog in peek after the
qlen is restored.
Fixes:
|
||
|
Victor Nogueira
|
097f6fc7b1 |
net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
Whenever fq_codel drops packets during peek, it calls
qdisc_tree_reduce_backlog. An issue arises because it calls
qdisc_tree_reduce_backlog before it reincrements the qlen. If qlen drops
to zero, but peek returns an skb, the parent's qlen_notify callback will be
executed even though fq_codel still has 1 packet on the queue and, thus,
will mistakenly deactivate the parent's class causing issues like a recent
report [1] and a wild memory access in qfq:
[ 29.371146][ T360] Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI
[ 29.371666][ T360] KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127]
[ 29.371987][ T360] CPU: 6 UID: 0 PID: 360 Comm: tc Not tainted 7.1.0-rc5-00285-gc530e5b2dbc6-dirty #82 PREEMPT(full)
[ 29.372384][ T360] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 29.372620][ T360] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:1029 (discriminator 2) include/linux/list.h:1043 (discriminator 2) net/sched/sch_qfq.c:1369 (discriminator 2) net/sched/sch_qfq.c:1395 (discriminator 2)) sch_qfq
[ 29.373544][ T360] RSP: 0018:ffff888102417370 EFLAGS: 00010216
[ 29.373800][ T360] RAX: 0000000000000000 RBX: ffff88811224d568 RCX: dffffc0000000000
[ 29.374079][ T360] RDX: 1ffff11021fe1543 RSI: ffff88810ff0aa00 RDI: dffffc0000000000
[ 29.374368][ T360] RBP: ffff88811224c280 R08: dead000000000122 R09: 1bd5a00000000024
[ 29.374649][ T360] R10: fffffbfff7940329 R11: fffffbfff7940329 R12: 0000000000000000
[ 29.374926][ T360] R13: dead000000000100 R14: ffff88811224d580 R15: ffff88811224d578
[ 29.375207][ T360] FS: 00007f5b794e5780(0000) GS:ffff88815d1e9000(0000) knlGS:0000000000000000
[ 29.375545][ T360] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 29.375823][ T360] CR2: 000055ffb091f000 CR3: 000000010a305000 CR4: 0000000000750ef0
[ 29.376103][ T360] PKRU: 55555554
[ 29.376258][ T360] Call Trace:
[ 29.376401][ T360] <TASK>
...
[ 29.376885][ T360] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1487) sch_qfq
[ 29.377074][ T360] qdisc_reset (net/sched/sch_generic.c:1057)
[ 29.377414][ T360] __qdisc_destroy (net/sched/sch_generic.c:1096)
[ 29.377600][ T360] qdisc_graft (net/sched/sch_api.c:1062 net/sched/sch_api.c:1053 net/sched/sch_api.c:1159)
[ 29.378593][ T360] tc_get_qdisc (net/sched/sch_api.c:1528 net/sched/sch_api.c:1556)
Fix this by only calling qdisc_tree_reduce_backlog in peek after the
qlen is restored.
[1] http://lore.kernel.org/netdev/CAN2cbVe79oj0O9==m4+4x3v+O+qzRagA=2=wkrp9i9=CqYvyZA@mail.gmail.com/
Fixes:
|
||
|
Samuel Moelius
|
d504a97857 |
net/sched: act_pedit: require matching IPv4 L4 protocol
The extended IPv4 L4 header mode in act_pedit can select TCP or UDP header fields without confirming that the IPv4 protocol field matches the selected transport header. That lets a rule written for TCP or UDP modify unrelated payload bytes in a packet carrying a different protocol. Verify that the IPv4 header is long enough, that the protocol matches the selected TCP or UDP header, and that the packet is not a non-initial fragment before applying TCP or UDP extended header edits. Cc: stable+noautosel@kernel.org # in real rule sets the match confirms this before calling the action Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|
Victor Nogueira
|
90b662ea25 |
net/sched: sch_hfsc: Don't make class passive twice
update_vf() is called from two places for the same class during a single
dequeue when the class's child qdisc (e.g. codel/fq_codel) drops its last
packets while dequeuing:
1. The child calls qdisc_tree_reduce_backlog(), which, now that the child
is empty, invokes hfsc_qlen_notify() -> update_vf(cl, 0, 0) and turns
the class passive (cl_nactive is decremented up the hierarchy).
2. hfsc_dequeue() then calls update_vf(cl, qdisc_pkt_len(skb), cur_time)
to charge the dequeued bytes.
On the second call the class is already passive, but its child qdisc is
still empty, so update_vf() arms go_passive again:
if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
go_passive = 1;
The leaf is then skipped by the cl_nactive == 0 check inside the loop,
which does not clear go_passive, so the stale go_passive propagates to the
parent and decrements its cl_nactive a second time. A parent that still
has other active children is driven to cl_nactive == 0 and removed from
the vttree, even though those siblings are still backlogged. They are
never dequeued again and the qdisc stalls.
Fix this by only arming go_passive when the class is actually active, so an
already-passive class no longer triggers a second passive transition. The
byte accounting (cl->cl_total += len) still runs for every ancestor, so
dequeued bytes continue to be counted exactly once.
Fixes:
|
||
|
Jamal Hadi Salim
|
f294fc71c4 |
net/sched: cls_flow: Dont expose folded kernel pointers
The flow classifier falls back to addr_fold() for fields that are missing
from packet headers. In map mode, userspace controls mask, xor, rshift,
addend and divisor, and can observe the resulting classid through class
statistics. This allows a tc classifier in a user/network namespace to
recover the 32-bit folded value of skb->sk, skb_dst() or skb_nfct().
Align with standard kernel practices for pointer hashing and replace the
XOR folding with a keyed siphash (which is cryptographically secure)
Fixes:
|
||
|
Jakub Kicinski
|
518d8d0199 |
net: sched: avoid printing uninitialized link speed
sch_cbs and sch_taprio print ecmd.base.speed, even if netif_get_link_ksettings() failed. When netif_get_link_ksettings() fails the ecmd may not be initialized. Use the always-initialized speed variable instead. The semantics change slightly because UNKNOWN will never be printed, but that doesn't seem important enough to complicate the code for. This is a _dbg() print, anyway. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260609183353.1109641-1-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
||
|
Willem de Bruijn
|
c4f796c4f1 |
net_sched: sch_fq: convert skb->tstamp if not monotonic
FQ currently assumes skb->tstamp holds monotonic time, as used by TCP. Users with ns_capable CAP_NET_ADMIN can transmit skbs using SO_TXTIME with CLOCK_MONOTONIC, CLOCK_REALTIME or CLOCK_TAI clockids as of commit |
||
|
Jakub Kicinski
|
8d72997dab |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc7). Silent conflicts: net/wireless/nl80211.c |
||
|
Jakub Kicinski
|
e50f6245be |
net: sched: don't recurse on the netdev ops lock in qdiscs
cbs_set_port_rate() and taprio_set_picos_per_byte() are reached from
two paths and both already hold the device's ops lock:
*_change(), via tc_modify_qdisc() which calls netdev_lock_ops(dev)
before dispatching to the qdisc ops.
*_dev_notifier() on NETDEV_UP / NETDEV_CHANGE, where caller
holds the ops lock across the notifier chain.
Switch to netif_get_link_ksettings() to avoid deadlock once
__ethtool_get_link_ksettings() starts taking the netdev lock.
Link: https://patch.msgid.link/20260603012840.2254293-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
||
|
Rajat Gupta
|
899ee91156 |
net/sched: fix pedit partial COW leading to page cache corruption
tcf_pedit_act() computes the COW range for skb_ensure_writable()
once before the key loop using tcfp_off_max_hint, but the hint does
not account for the runtime header offset added by typed keys. This
can leave part of the write region un-COW'd.
Fix by moving skb_ensure_writable() inside the per-key loop where
the actual write offset is known, and add overflow checking on the
offset arithmetic. For negative offsets (e.g. Ethernet header edits
at ingress), use skb_cow() to COW the headroom instead. Guard
offset_valid() against INT_MIN, where negation is undefined.
Fixes:
|
||
|
Jamal Hadi Salim
|
5057e1aca0 |
net/sched: act_api: use RCU with deferred freeing for action lifecycle
When NEWTFILTER and DELFILTER are run concurrently it is possible to create a race with an associated action. Let's illustrate with CPU0 running NEWTFILTER and CPU1 running DELFILTER: 0: mutex_lock() <-- holds the idr lock 0: rcu_read_lock() 0: p = idr_find(idr, index) <-- action p is valid (RCU protects IDR) 0: mutex_unlock() <-- releases the idr lock 1: refcount_dec_and_mutex_lock() <-- refcnt 1->0, mutex held 1: idr_remove(idr, index) <-- Action removed from IDR 1: mutex_unlock() <-- mutex released allowing us to delete the action 1: tcf_action_cleanup(p); kfree(p) <-- Kfrees p immediately, no deferral 0: refcount_inc_not_zero(&p->tcfa_refcnt) <-- ouch, UAF p points to freed memory This patch fixes the race condition between NEWTFILTER and DELFILTER by adding struct rcu_head to tc_action used in the deferral and introducing a call_rcu() in the delete path to defer the final kfree(). Note: this is a revert of commit |
||
|
Jakub Kicinski
|
d44646fc9e |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc6). Conflicts: drivers/net/phy/air_en8811h.c |
||
|
Victor Nogueira
|
e80ad525fc |
net/sched: act_mirred: Fix return code in early mirred redirect error paths
Since retval is set as TC_ACT_STOLEN in the mirred redirect case, returning
retval in cases where redirect failed will make the callers not register
the skb as being dropped.
Fix this by returning TC_ACT_SHOT instead in such scenarios.
Fixes:
|
||
|
Kito Xu (veritas501)
|
a005fa5d75 |
net/sched: act_mirred: Fix blockcast recursion bypass leading to stack overflow
tcf_mirred_act() checks sched_mirred_nest against MIRRED_NEST_LIMIT (4)
to prevent deep recursion. However, when the action uses blockcast
(tcfm_blockid != 0), the function returns at the tcf_blockcast() call
BEFORE reaching the counter increment. As a result, the recursion
counter never advances and the limit check is entirely bypassed.
When two devices share a TC egress block with a mirred blockcast rule,
a packet egressing on device A is mirrored to device B via blockcast;
device B's egress TC re-enters tcf_mirred_act() via blockcast and
mirrors back to A, creating an unbounded recursion loop:
tcf_mirred_act -> tcf_blockcast -> tcf_mirred_to_dev -> dev_queue_xmit
-> sch_handle_egress -> tcf_classify -> tcf_mirred_act -> (repeat)
This recursion continues until the kernel stack overflows.
The bug is reachable from an unprivileged user via
unshare(CLONE_NEWUSER | CLONE_NEWNET): user namespaces grant
CAP_NET_ADMIN in the new network namespace, which is sufficient to
create dummy devices, attach clsact qdiscs with shared blocks, and
install mirred blockcast filters.
BUG: TASK stack guard page was hit at ffffc90000b7fff8
Oops: stack guard page: 0000 [#1] SMP KASAN NOPTI
CPU: 2 UID: 1000 PID: 169 Comm: poc Not tainted 7.0.0-rc7-next-20260410
RIP: 0010:xas_find+0x17/0x480
Call Trace:
xa_find+0x17b/0x1d0
tcf_mirred_act+0x640/0x1060
tcf_action_exec+0x400/0x530
basic_classify+0x128/0x1d0
tcf_classify+0xd83/0x1150
tc_run+0x328/0x620
__dev_queue_xmit+0x797/0x3100
tcf_mirred_to_dev+0x7b1/0xf70
tcf_mirred_act+0x68a/0x1060
[repeating ~30+ times until stack overflow]
Kernel panic - not syncing: Fatal exception in interrupt
Fix this by incrementing sched_mirred_nest before calling
tcf_blockcast() and decrementing it on return, mirroring the
non-blockcast path. This ensures subsequent recursive entries see the
updated counter and are correctly limited by MIRRED_NEST_LIMIT.
Fixes:
|
||
|
Jamal Hadi Salim
|
db875221ab |
net/sched: Fix ethx:ingress -> ethy:egress -> ethx:ingress mirred loop
When mirred redirects to ingress (from either ingress or egress) the loop
state from sched_mirred_dev array dev is lost because of 1) the packet
deferral into the backlog and 2) the fact the sched_mirred_dev array is
cleared. In such cases, if there was a loop we won't discover it.
Here's a simple test to reproduce:
ip a add dev port0 10.10.10.11/24
tc qdisc add dev port0 clsact
tc filter add dev port0 egress protocol ip \
prio 10 matchall action mirred ingress redirect dev port1
tc qdisc add dev port1 clsact
tc filter add dev port1 ingress protocol ip \
prio 10 matchall action mirred egress redirect dev port0
ping -c 1 -W0.01 10.10.10.10
Fixes:
|
||
|
Jamal Hadi Salim
|
9552b11e3e |
net/sched: fix packet loop on netem when duplicate is on
When netem duplicates a packet it re-enqueues the copy at the root qdisc.
If another netem sits in the tree the copy can be duplicated
again, recursing until the stack or memory is exhausted.
The original duplication guard temporarily zeroed q->duplicate around
the re-enqueue, but that does not cover all cases because it is
per-qdisc state shared across all concurrent enqueue paths
and is not safe without additional locking.
Use the skb tc_depth field introduced in an earlier patch:
- increment it on the duplicate before re-enqueue
- skip duplication for any skb whose tc_depth is already non-zero.
This marks the packet itself rather than mutating qdisc state,
therefore it is safe regardless of tree topology or concurrency.
Fixes:
|