IM
IronMonkey Threat Research

CVE-2026-31423 MEDIUM

Published: 2026-04-13 | Last Modified: 2026-07-14 | Status: Modified

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.

CVSS Metrics

Base Score: 5.5 (MEDIUM)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 3.6

Weaknesses

Source Type Description
[email protected] Primary
en CWE-369

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x702bdc59f1c0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702ba6a939c0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702ba6a90b40> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdd650c40> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdc59dd00> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdc242000> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bddaf4b40> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702b80d1b7c0> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bde536880> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bdc59d480> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bde536fc0> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bde536dc0> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702bdc558380> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702bdd4ad580> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702b80ada9c0> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702ba6a72a00> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702bdd651380> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x702bdc132800> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

References

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