| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-37752: net_sched: sch_sfq: move the limit validation |
| |
| 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 |
| |
| The Linux kernel CVE team has assigned CVE-2025-37752 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.1.129 with commit 35d0137305ae2f97260a9047f445bd4434bd6cc7 and fixed in 6.1.135 with commit 1348214fa042a71406964097e743c87a42c85a49 |
| Issue introduced in 6.6.76 with commit 833e9a1c27b82024db7ff5038a51651f48f05e5e and fixed in 6.6.88 with commit d2718324f9e329b10ddc091fba5a0ba2b9d4d96a |
| Issue introduced in 6.12.13 with commit 7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4 and fixed in 6.12.24 with commit f86293adce0c201cfabb283ef9d6f21292089bb8 |
| Issue introduced in 6.13.2 with commit 7fefc294204f10a3405f175f4ac2be16d63f135e and fixed in 6.13.12 with commit 5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d |
| Issue introduced in 6.14 with commit 10685681bafce6febb39770f3387621bf5d67d0b and fixed in 6.14.3 with commit b36a68192037d1614317a09b0d78c7814e2eecf9 |
| Issue introduced in 6.14 with commit 10685681bafce6febb39770f3387621bf5d67d0b and fixed in 6.15 with commit b3bf8f63e6179076b57c9de660c9f80b5abefe70 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-37752 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/sched/sch_sfq.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/1348214fa042a71406964097e743c87a42c85a49 |
| https://git.kernel.org/stable/c/d2718324f9e329b10ddc091fba5a0ba2b9d4d96a |
| https://git.kernel.org/stable/c/f86293adce0c201cfabb283ef9d6f21292089bb8 |
| https://git.kernel.org/stable/c/5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d |
| https://git.kernel.org/stable/c/b36a68192037d1614317a09b0d78c7814e2eecf9 |
| https://git.kernel.org/stable/c/b3bf8f63e6179076b57c9de660c9f80b5abefe70 |
