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

Timeline

Scores

EPSS (exploitation in 30 days)

0.30% · top 77% of all CVEs (12 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected e12f6013d0a69660e8b99bfe381b9546ae667328 – < 8fadc871a42933aacb7f1ce9ed9a96485e2c9cf4
  • affected 1e6d9d87626cf89eeffb4d943db12cb5b10bf961 – < 7d62ded97db6b7c94c891f704151f372b1ba4688
  • affected 1b562b7f9231432da40d12e19786c1bd7df653a7 – < 6c589aa318023690f1606c666a7fb5f4c1c9c219
  • affected 35d0137305ae2f97260a9047f445bd4434bd6cc7 – < 1348214fa042a71406964097e743c87a42c85a49
  • affected 833e9a1c27b82024db7ff5038a51651f48f05e5e – < d2718324f9e329b10ddc091fba5a0ba2b9d4d96a
  • affected 7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4 – < f86293adce0c201cfabb283ef9d6f21292089bb8
  • affected 7fefc294204f10a3405f175f4ac2be16d63f135e – < 5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d
  • affected 10685681bafce6febb39770f3387621bf5d67d0b – < b36a68192037d1614317a09b0d78c7814e2eecf9
  • affected 10685681bafce6febb39770f3387621bf5d67d0b – < b3bf8f63e6179076b57c9de660c9f80b5abefe70
  • affected 6.1.129 – < 6.1.135
  • affected 6.6.76 – < 6.6.88
  • affected 6.12.13 – < 6.12.24
  • affected 6.13.2 – < 6.13.12

• Linux · Linux

  • affected 6.14
  • unaffected < 6.14
  • unaffected 6.1.135 – ≤ 6.1.*
  • unaffected 6.6.88 – ≤ 6.6.*
  • unaffected 6.12.24 – ≤ 6.12.*
  • unaffected 6.13.12 – ≤ 6.13.*
  • unaffected 6.14.3 – ≤ 6.14.*
  • unaffected 6.15 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2025-13064 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2025-37752](https://cveledger.app/badge/CVE-2025-37752.svg)](https://cveledger.app/cve/CVE-2025-37752)

Record last updated 5 Aug 2026, 11:57 UTC.