Description
In the Linux kernel, the following vulnerability has been resolved: net_sched: ets: fix a race in ets_qdisc_change() Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.
Affected products
linux: linux kernel; debian: debian linux
References9
- git.kernel.org/stable/c/0383b25488a545be168744336847549d4a2d3d6c Patch
- git.kernel.org/stable/c/073f64c03516bcfaf790f8edc772e0cfb8a84ec3 Patch
- git.kernel.org/stable/c/0b479d0aa488cb478eb2e1d8868be946ac8afb4f Patch
- git.kernel.org/stable/c/347867cb424edae5fec1622712c8dd0a2c42918f Patch
- git.kernel.org/stable/c/d92adacdd8c2960be856e0b82acc5b7c5395fddb Patch
- git.kernel.org/stable/c/eb7b74e9754e1ba2088f914ad1f57a778b11894b Patch
- git.kernel.org/stable/c/fed94bd51d62d2e0e006aa61480e94e5cd0582b0 Patch
- lists.debian.org/debian-lts-announce/2025/10/msg00007.html Mailing ListThird Party Advisory
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html Mailing ListThird Party Advisory
Metrics
- CVSS 3.1
-
7.0
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 5 · as of 7 November 2026
- CWE
- CWE-362
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