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[lts 8.6-rt] ooops all breaks - #87

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[lts 8.6-rt] ooops all breaks#87
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PlaidCatforce-pushed the {jmaple}_ciqlts8_6-rt branch from e83f1a0 to b2dd08eCompareJanuary 23, 2025 00:35
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PlaidCatforce-pushed the {jmaple}_test_ciqlts8_6-rt branch from 5d37eeb to f14fb84CompareJanuary 23, 2025 00:42
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PlaidCat deleted the branch ctrliq:{jmaple}_ciqlts8_6-rtJanuary 27, 2025 14:24
PlaidCat added a commit that referenced this pull request Mar 12, 2025
jira LE-2522
cve CVE-2024-53177
Rebuild_History Non-Buildable kernel-5.14.0-503.29.1.el9_5
commit-author Paul Aurich <paul@darkrain42.org>
commit a9685b4
If open_cached_dir() encounters an error parsing the lease from the
server, the error handling may race with receiving a lease break,
resulting in open_cached_dir() freeing the cfid while the queued work is
pending.
Update open_cached_dir() to drop refs rather than directly freeing the
cfid.
Have cached_dir_lease_break(), cfids_laundromat_worker(), and
invalidate_all_cached_dirs() clear has_lease immediately while still
holding cfids->cfid_list_lock, and then use this to also simplify the
reference counting in cfids_laundromat_worker() and
invalidate_all_cached_dirs().
Fixes this KASAN splat (which manually injects an error and lease break
in open_cached_dir()):
==================================================================
BUG: KASAN: slab-use-after-free in smb2_cached_lease_break+0x27/0xb0
Read of size 8 at addr ffff88811cc24c10 by task kworker/3:1/65
CPU: 3 UID: 0 PID: 65 Comm: kworker/3:1 Not tainted 6.12.0-rc6-g255cf264e6e5-dirty #87
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
Workqueue: cifsiod smb2_cached_lease_break
Call Trace:
<TASK>
dump_stack_lvl+0x77/0xb0
print_report+0xce/0x660
kasan_report+0xd3/0x110
smb2_cached_lease_break+0x27/0xb0
process_one_work+0x50a/0xc50
worker_thread+0x2ba/0x530
kthread+0x17c/0x1c0
ret_from_fork+0x34/0x60
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 2464:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
open_cached_dir+0xa7d/0x1fb0
smb2_query_path_info+0x43c/0x6e0
cifs_get_fattr+0x346/0xf10
cifs_get_inode_info+0x157/0x210
cifs_revalidate_dentry_attr+0x2d1/0x460
cifs_getattr+0x173/0x470
vfs_statx_path+0x10f/0x160
vfs_statx+0xe9/0x150
vfs_fstatat+0x5e/0xc0
__do_sys_newfstatat+0x91/0xf0
do_syscall_64+0x95/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 2464:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x51/0x70
kfree+0x174/0x520
open_cached_dir+0x97f/0x1fb0
smb2_query_path_info+0x43c/0x6e0
cifs_get_fattr+0x346/0xf10
cifs_get_inode_info+0x157/0x210
cifs_revalidate_dentry_attr+0x2d1/0x460
cifs_getattr+0x173/0x470
vfs_statx_path+0x10f/0x160
vfs_statx+0xe9/0x150
vfs_fstatat+0x5e/0xc0
__do_sys_newfstatat+0x91/0xf0
do_syscall_64+0x95/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Last potentially related work creation:
kasan_save_stack+0x33/0x60
__kasan_record_aux_stack+0xad/0xc0
insert_work+0x32/0x100
__queue_work+0x5c9/0x870
queue_work_on+0x82/0x90
open_cached_dir+0x1369/0x1fb0
smb2_query_path_info+0x43c/0x6e0
cifs_get_fattr+0x346/0xf10
cifs_get_inode_info+0x157/0x210
cifs_revalidate_dentry_attr+0x2d1/0x460
cifs_getattr+0x173/0x470
vfs_statx_path+0x10f/0x160
vfs_statx+0xe9/0x150
vfs_fstatat+0x5e/0xc0
__do_sys_newfstatat+0x91/0xf0
do_syscall_64+0x95/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff88811cc24c00
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 16 bytes inside of
freed 1024-byte region [ffff88811cc24c00, ffff88811cc25000)
Cc: stable@vger.kernel.org
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
(cherry picked from commit a9685b4)
Signed-off-by: Jonathan Maple <jmaple@ciq.com>
github-actionsBot pushed a commit that referenced this pull request Sep 12, 2025
Small cleanup and test extension to probe the bpf_crypto_{encrypt,decrypt}()
kfunc when a bad dst buffer is passed in to assert that an error is returned.
Also, encrypt_sanity() and skb_crypto_setup() were explicit to set the global
status variable to zero before any test, so do the same for decrypt_sanity().
Do not explicitly zero the on-stack err before bpf_crypto_ctx_create() given
the kfunc is expected to do it internally for the success case.
Before kernel fix:
# ./vmtest.sh -- ./test_progs -t crypto
[...]
[ 1.531200] bpf_testmod: loading out-of-tree module taints kernel.
[ 1.533388] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#87/1 crypto_basic/crypto_release:OK
#87/2 crypto_basic/crypto_acquire:OK
#87 crypto_basic:OK
test_crypto_sanity:PASS:skel open 0 nsec
test_crypto_sanity:PASS:ip netns add crypto_sanity_ns 0 nsec
test_crypto_sanity:PASS:ip -net crypto_sanity_ns -6 addr add face::1/128 dev lo nodad 0 nsec
test_crypto_sanity:PASS:ip -net crypto_sanity_ns link set dev lo up 0 nsec
test_crypto_sanity:PASS:open_netns 0 nsec
test_crypto_sanity:PASS:AF_ALG init fail 0 nsec
test_crypto_sanity:PASS:if_nametoindex lo 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup fd 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup retval 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup status 0 nsec
test_crypto_sanity:PASS:create qdisc hook 0 nsec
test_crypto_sanity:PASS:make_sockaddr 0 nsec
test_crypto_sanity:PASS:attach encrypt filter 0 nsec
test_crypto_sanity:PASS:encrypt socket 0 nsec
test_crypto_sanity:PASS:encrypt send 0 nsec
test_crypto_sanity:FAIL:encrypt status unexpected error: -5 (errno 95)
#88 crypto_sanity:FAIL
Summary: 1/2 PASSED, 0 SKIPPED, 1 FAILED
After kernel fix:
# ./vmtest.sh -- ./test_progs -t crypto
[...]
[ 1.540963] bpf_testmod: loading out-of-tree module taints kernel.
[ 1.542404] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#87/1 crypto_basic/crypto_release:OK
#87/2 crypto_basic/crypto_acquire:OK
#87 crypto_basic:OK
#88 crypto_sanity:OK
Summary: 2/2 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/r/20250829143657.318524-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
github-actionsBot pushed a commit that referenced this pull request Nov 28, 2025
JIRA: https://issues.redhat.com/browse/RHEL-78204
commit 3aa9b9a
Author: Daniel Borkmann <daniel@iogearbox.net>
Date: Fri Aug 29 16:36:57 2025 +0200
selftests/bpf: Extend crypto_sanity selftest with invalid dst buffer
Small cleanup and test extension to probe the bpf_crypto_{encrypt,decrypt}()
kfunc when a bad dst buffer is passed in to assert that an error is returned.
Also, encrypt_sanity() and skb_crypto_setup() were explicit to set the global
status variable to zero before any test, so do the same for decrypt_sanity().
Do not explicitly zero the on-stack err before bpf_crypto_ctx_create() given
the kfunc is expected to do it internally for the success case.
Before kernel fix:
# ./vmtest.sh -- ./test_progs -t crypto
[...]
[ 1.531200] bpf_testmod: loading out-of-tree module taints kernel.
[ 1.533388] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#87/1 crypto_basic/crypto_release:OK
#87/2 crypto_basic/crypto_acquire:OK
#87 crypto_basic:OK
test_crypto_sanity:PASS:skel open 0 nsec
test_crypto_sanity:PASS:ip netns add crypto_sanity_ns 0 nsec
test_crypto_sanity:PASS:ip -net crypto_sanity_ns -6 addr add face::1/128 dev lo nodad 0 nsec
test_crypto_sanity:PASS:ip -net crypto_sanity_ns link set dev lo up 0 nsec
test_crypto_sanity:PASS:open_netns 0 nsec
test_crypto_sanity:PASS:AF_ALG init fail 0 nsec
test_crypto_sanity:PASS:if_nametoindex lo 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup fd 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup retval 0 nsec
test_crypto_sanity:PASS:skb_crypto_setup status 0 nsec
test_crypto_sanity:PASS:create qdisc hook 0 nsec
test_crypto_sanity:PASS:make_sockaddr 0 nsec
test_crypto_sanity:PASS:attach encrypt filter 0 nsec
test_crypto_sanity:PASS:encrypt socket 0 nsec
test_crypto_sanity:PASS:encrypt send 0 nsec
test_crypto_sanity:FAIL:encrypt status unexpected error: -5 (errno 95)
#88 crypto_sanity:FAIL
Summary: 1/2 PASSED, 0 SKIPPED, 1 FAILED
After kernel fix:
# ./vmtest.sh -- ./test_progs -t crypto
[...]
[ 1.540963] bpf_testmod: loading out-of-tree module taints kernel.
[ 1.542404] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#87/1 crypto_basic/crypto_release:OK
#87/2 crypto_basic/crypto_acquire:OK
#87 crypto_basic:OK
#88 crypto_sanity:OK
Summary: 2/2 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/r/20250829143657.318524-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
github-actionsBot pushed a commit that referenced this pull request Feb 2, 2026
JIRA: https://issues.redhat.com/browse/RHEL-140878
commit c2b47df upstream.
[BUG]
With CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash
with the following VM_BUG_ON_FOLIO():
BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28
BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28
page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664
aops:btrfs_aops [btrfs] ino:101 dentry name(?):"f1774"
flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff)
page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio))
------------[ cut here ]------------
kernel BUG at mm/page-writeback.c:2992!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G OE 6.12.0-rc7-custom+ #87
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
pc : folio_clear_dirty_for_io+0x128/0x258
lr : folio_clear_dirty_for_io+0x128/0x258
Call trace:
folio_clear_dirty_for_io+0x128/0x258
btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs]
__process_folios_contig+0x154/0x268 [btrfs]
extent_clear_unlock_delalloc+0x5c/0x80 [btrfs]
run_delalloc_nocow+0x5f8/0x760 [btrfs]
btrfs_run_delalloc_range+0xa8/0x220 [btrfs]
writepage_delalloc+0x230/0x4c8 [btrfs]
extent_writepage+0xb8/0x358 [btrfs]
extent_write_cache_pages+0x21c/0x4e8 [btrfs]
btrfs_writepages+0x94/0x150 [btrfs]
do_writepages+0x74/0x190
filemap_fdatawrite_wbc+0x88/0xc8
start_delalloc_inodes+0x178/0x3a8 [btrfs]
btrfs_start_delalloc_roots+0x174/0x280 [btrfs]
shrink_delalloc+0x114/0x280 [btrfs]
flush_space+0x250/0x2f8 [btrfs]
btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
process_one_work+0x164/0x408
worker_thread+0x25c/0x388
kthread+0x100/0x118
ret_from_fork+0x10/0x20
Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000)
---[ end trace 0000000000000000 ]---
[CAUSE]
The first two lines of extra debug messages show the problem is caused
by the error handling of run_delalloc_nocow().
E.g. we have the following dirtied range (4K blocksize 4K page size):
0 16K 32K
|//////////////////////////////////////|
| Pre-allocated |
And the range [0, 16K) has a preallocated extent.
- Enter run_delalloc_nocow() for range [0, 16K)
Which found range [0, 16K) is preallocated, can do the proper NOCOW
write.
- Enter fallback_to_fow() for range [16K, 32K)
Since the range [16K, 32K) is not backed by preallocated extent, we
have to go COW.
- cow_file_range() failed for range [16K, 32K)
So cow_file_range() will do the clean up by clearing folio dirty,
unlock the folios.
Now the folios in range [16K, 32K) is unlocked.
- Enter extent_clear_unlock_delalloc() from run_delalloc_nocow()
Which is called with PAGE_START_WRITEBACK to start page writeback.
But folios can only be marked writeback when it's properly locked,
thus this triggered the VM_BUG_ON_FOLIO().
Furthermore there is another hidden but common bug that
run_delalloc_nocow() is not clearing the folio dirty flags in its error
handling path.
This is the common bug shared between run_delalloc_nocow() and
cow_file_range().
[FIX]
- Clear folio dirty for range [@start, @cur_offset)
Introduce a helper, cleanup_dirty_folios(), which
will find and lock the folio in the range, clear the dirty flag and
start/end the writeback, with the extra handling for the
@locked_folio.
- Introduce a helper to clear folio dirty, start and end writeback
- Introduce a helper to record the last failed COW range end
This is to trace which range we should skip, to avoid double
unlocking.
- Skip the failed COW range for the error handling
CC: stable@vger.kernel.org
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 5ae72ab)
Signed-off-by: Ravi Singh <ravising@redhat.com>
github-actionsBot pushed a commit that referenced this pull request Mar 28, 2026
JIRA: https://issues.redhat.com/browse/RHEL-150155
Upstream Status: linux.git
commit 586ceac
Author: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Wed Apr 30 17:53:29 2025 -0700
ipv6: Restore fib6_config validation for SIOCADDRT.
syzkaller reported out-of-bounds read in ipv6_addr_prefix(),
where the prefix length was over 128.
The cited commit accidentally removed some fib6_config
validation from the ioctl path.
Let's restore the validation.
[0]:
BUG: KASAN: slab-out-of-bounds in ip6_route_info_create (./include/net/ipv6.h:616 net/ipv6/route.c:3814)
Read of size 1 at addr ff11000138020ad4 by task repro/261
CPU: 3 UID: 0 PID: 261 Comm: repro Not tainted 6.15.0-rc3-00614-g0d15a26b247d #87 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:123)
print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)
kasan_report (mm/kasan/report.c:636)
ip6_route_info_create (./include/net/ipv6.h:616 net/ipv6/route.c:3814)
ip6_route_add (net/ipv6/route.c:3902)
ipv6_route_ioctl (net/ipv6/route.c:4523)
inet6_ioctl (net/ipv6/af_inet6.c:577)
sock_do_ioctl (net/socket.c:1190)
sock_ioctl (net/socket.c:1314)
__x64_sys_ioctl (fs/ioctl.c:51 fs/ioctl.c:906 fs/ioctl.c:892 fs/ioctl.c:892)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
RIP: 0033:0x7f518fb2de5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007fff14f38d18 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f518fb2de5d
RDX: 00000000200015c0 RSI: 000000000000890b RDI: 0000000000000003
RBP: 00007fff14f38d30 R08: 0000000000000800 R09: 0000000000000800
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff14f38e48
R13: 0000000000401136 R14: 0000000000403df0 R15: 00007f518fd3c000
</TASK>
Fixes: fa76c16 ("ipv6: Move some validation from ip6_route_info_create() to rtm_to_fib6_config().")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: Yi Lai <yi1.lai@linux.intel.com>
Closes: https://lore.kernel.org/netdev/aBAcKDEFoN%2FLntBF@ly-workstation/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250501005335.53683-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Antoine Tenart <atenart@redhat.com>
github-actionsBot pushed a commit that referenced this pull request Jun 17, 2026
…ek 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: 342debc ("codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260610192855.3121513-3-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
github-actionsBot pushed a commit that referenced this pull request Jul 24, 2026
…ek before restoring qlen
[ Upstream commit 52f1da3 ]
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: 342debc ("codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260610192855.3121513-3-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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