CVE-2025-40083
net/sched: sch_qfq: Fix null-deref in agg_dequeue
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: Fix null-deref in agg_dequeue To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c) when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return value before using it, similar to the existing approach in sch_hfsc.c. To avoid code duplication, the following changes are made: 1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static inline function. 2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to include/net/pkt_sched.h so that sch_qfq can reuse it. 3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
3.8
References 7
git.kernel.org
- stable/c/71d84658a61322e5630c85c5388fc25e4a2d08b2
- stable/c/99fc137f178797204d36ac860dd8b31e35baa2df
- stable/c/1bed56f089f09b465420bf23bb32985c305cfc28
- stable/c/3c2a8994807623c7655ece205667ae2cf74940aa
- stable/c/6ffa9d66187188e3068b5a3895e6ae1ee34f9199
- stable/c/6ff8e74c8f8a68ec07ef837b95425dfe900d060f
- stable/c/dd831ac8221e691e9e918585b1003c7071df0379