CVE-2026-31423
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_hfsc: fix divide-by-zero in rtsc_min() m2sm() converts a u32 slope to a u64 scaled value. For large inputs (e.g. m1=4000000000), the result can reach 2^32. rtsc_min() stores the difference of two such u64 values in a u32 variable `dsm` and uses it as a divisor. When the difference is exactly 2^32 the truncation yields zero, causing a divide-by-zero oops in the concave-curve intersection path: Oops: divide error: 0000 RIP: 0010:rtsc_min (net/sched/sch_hfsc.c:601) Call Trace: init_ed (net/sched/sch_hfsc.c:629) hfsc_enqueue (net/sched/sch_hfsc.c:1569) [...] Widen `dsm` to u64 and replace do_div() with div64_u64() so the full difference is preserved.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.170-1 |
| debian | bullseye | fixed | 6.1.170-1~deb11u1 |
| debian | forky | fixed | 6.19.12-1 |
| debian | sid | fixed | 6.19.12-1 |
| debian | trixie | fixed | 6.12.85-1 |
| linux-kernel | affected | 5.10.253 | |
| linux-kernel | 2.6.12 | affected | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/17c1b9807b8a67d676b6dcf749ee932ebaa7f568
- https://git.kernel.org/stable/c/25b6821884713a31e2b49fb67b0ebd765b33e0a9
- https://git.kernel.org/stable/c/4576100b8cd03118267513cafacde164b498b322
- https://git.kernel.org/stable/c/ab1ff5890c7354afc7be56502fcfbd61f3b7ae4f
- https://git.kernel.org/stable/c/ad8e8fec40290a8c8cf145c0deaadf76f80c5163
- https://git.kernel.org/stable/c/b9e6431cbea8bb1fae8069ed099b4ee100499835
- https://git.kernel.org/stable/c/c56f78614e7781aaceca9bd3cb2128bf7d45c3bd
- https://git.kernel.org/stable/c/d0aefec1b1a1ba2c1d251028dc2c4e5b4ce1fea5
- https://www.suse.com/security/cve/CVE-2026-31423.html
- https://security-tracker.debian.org/tracker/CVE-2026-31423
CWEs
CWE-369
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.