CVE-2024-44938: jfs: Fix shift-out-of-bounds in dbDiscardAG

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-26 · updated 2026-06-17
Weakness: CWE-787

Description

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix shift-out-of-bounds in dbDiscardAG When searching for the next smaller log2 block, BLKSTOL2() returned 0, causing shift exponent -1 to be negative. This patch fixes the issue by exiting the loop directly when negative shift is found.

Affected products

Linux kernel: before 6.6.47; from 6.7 before 6.10.6 — fixed in 6.10.6, 6.6.47

How to fix

Upgrade to a fixed version: Linux kernel 6.10.6, 6.6.47. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/234e6ea0855cdb5673d54ecaf7dc5c78f3e84630
https://git.kernel.org/stable/c/4de2c04c3acd5b84f50b0d2f8f09e9b2f42374b9
https://git.kernel.org/stable/c/7063b80268e2593e58bee8a8d709c2f3ff93e2f2
https://git.kernel.org/stable/c/bb7c605a754823b86dd74f6537ccb9d38a9dec5a
https://git.kernel.org/stable/c/bd04a149e3a29e7f71b7956ed41dba34e42d539e
https://git.kernel.org/stable/c/f650148b43949ca9e37e820804bb6026fff404f3
https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html

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