CVE-2025-40083

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 71d84658a61322e5630c85c5388fc25e4a2d08b2affected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 99fc137f178797204d36ac860dd8b31e35baa2dfaffected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 1bed56f089f09b465420bf23bb32985c305cfc28affected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 3c2a8994807623c7655ece205667ae2cf74940aaaffected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 6ffa9d66187188e3068b5a3895e6ae1ee34f9199affected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < 6ff8e74c8f8a68ec07ef837b95425dfe900d060faffected
LinuxLinux462dbc9101acd38e92eda93c0726857517a24bbd < dd831ac8221e691e9e918585b1003c7071df0379affected
LinuxLinux3.8affected
LinuxLinux0 < 3.8unaffected
LinuxLinux5.4.302 <= 5.4.*unaffected
LinuxLinux5.10.247 <= 5.10.*unaffected
LinuxLinux5.15.197 <= 5.15.*unaffected
LinuxLinux6.1.159 <= 6.1.*unaffected
LinuxLinux6.6.116 <= 6.6.*unaffected
LinuxLinux6.12.57 <= 6.12.*unaffected
LinuxLinux6.16 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References