Description
In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: move the limit validation It is not sufficient to directly validate the limit on the data that the user passes as it can be updated based on how the other parameters are changed. Move the check at the end of the configuration update process to also catch scenarios where the limit is indirectly updated, for example with the following configurations: tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 depth 1 tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 divisor 1 This fixes the following syzkaller reported crash: ------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:203:6 index 65535 is out of range for type 'struct sfq_head[128]' CPU: 1 UID: 0 PID: 3037 Comm: syz.2.16 Not tainted 6.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x201/0x300 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_out_of_bounds+0xf5/0x120 lib/ubsan.c:429 sfq_link net/sched/sch_sfq.c:203 [inline] sfq_dec+0x53c/0x610 net/sched/sch_sfq.c:231 sfq_dequeue+0x34e/0x8c0 net/sched/sch_sfq.c:493 sfq_reset+0x17/0x60 net/sched/sch_sfq.c:518 qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035 tbf_reset+0x41/0x110 net/sched/sch_tbf.c:339 qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035 dev_reset_queue+0x100/0x1b0 net/sched/sch_generic.c:1311 netdev_for_each_tx_queue include/linux/netdevice.h:2590 [inline] dev_deactivate_many+0x7e5/0xe70 net/sched/sch_generic.c:1375
Product status
e12f6013d0a69660e8b99bfe381b9546ae667328 (git) before 8fadc871a42933aacb7f1ce9ed9a96485e2c9cf4
1e6d9d87626cf89eeffb4d943db12cb5b10bf961 (git) before 7d62ded97db6b7c94c891f704151f372b1ba4688
1b562b7f9231432da40d12e19786c1bd7df653a7 (git) before 6c589aa318023690f1606c666a7fb5f4c1c9c219
35d0137305ae2f97260a9047f445bd4434bd6cc7 (git) before 1348214fa042a71406964097e743c87a42c85a49
833e9a1c27b82024db7ff5038a51651f48f05e5e (git) before d2718324f9e329b10ddc091fba5a0ba2b9d4d96a
7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4 (git) before f86293adce0c201cfabb283ef9d6f21292089bb8
7fefc294204f10a3405f175f4ac2be16d63f135e (git) before 5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d
10685681bafce6febb39770f3387621bf5d67d0b (git) before b36a68192037d1614317a09b0d78c7814e2eecf9
10685681bafce6febb39770f3387621bf5d67d0b (git) before b3bf8f63e6179076b57c9de660c9f80b5abefe70
6.1.129 (semver) before 6.1.135
6.6.76 (semver) before 6.6.88
6.12.13 (semver) before 6.12.24
6.13.2 (semver) before 6.13.12
6.14
Any version before 6.14
6.1.135 (semver)
6.6.88 (semver)
6.12.24 (semver)
6.13.12 (semver)
6.14.3 (semver)
6.15 (original_commit_for_fix)
References
lists.debian.org/debian-lts-announce/2025/05/msg00045.html
git.kernel.org/...c/8fadc871a42933aacb7f1ce9ed9a96485e2c9cf4
git.kernel.org/...c/7d62ded97db6b7c94c891f704151f372b1ba4688
git.kernel.org/...c/6c589aa318023690f1606c666a7fb5f4c1c9c219
git.kernel.org/...c/1348214fa042a71406964097e743c87a42c85a49
git.kernel.org/...c/d2718324f9e329b10ddc091fba5a0ba2b9d4d96a
git.kernel.org/...c/f86293adce0c201cfabb283ef9d6f21292089bb8
git.kernel.org/...c/5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d
git.kernel.org/...c/b36a68192037d1614317a09b0d78c7814e2eecf9
git.kernel.org/...c/b3bf8f63e6179076b57c9de660c9f80b5abefe70