In the Linux kernel, the following vulnerability has been resolved:

squashfs: Add dictionary size range check to prevent shift-out-of-bounds

When an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size
is 0) is mounted, and performs shift operations using dictionarysize, the
shift exponent is -1, causing a shift-out-of-bounds.

Detail as below:
squashfs_comp_opts(msblk, buffer, length)
squashfs_xz_comp_opts()
if (comp_opts)
n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1
if (opts->dict_size != (1 << n) && opts->dict_size !=
(1 << n) + (1 << (n + 1))) <----shift-out-of-bounds

Fix it by adding a dictionary size range check before the shift operation.

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References
Link Providers
https://git.kernel.org/stable/c/0cb85377daaefb4ce5ce72975f2deb27ee0e0cad cve-icon cve-icon
https://git.kernel.org/stable/c/1f7745fb3580152ca902ef181b605f33cabfb1d0 cve-icon cve-icon
https://git.kernel.org/stable/c/7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1 cve-icon cve-icon
https://git.kernel.org/stable/c/88c673a0bd233df44ca0020da82f4fd3876de27a cve-icon cve-icon
https://git.kernel.org/stable/c/9d9c5c218ea356a1d88765214ad2919605280ab1 cve-icon cve-icon
https://git.kernel.org/stable/c/b02948a23455f8190a53887b2d2c13ae1d360cea cve-icon cve-icon
https://git.kernel.org/stable/c/c68e0068a236f9a7dfc19720bdf11e5d80a85089 cve-icon cve-icon
https://git.kernel.org/stable/c/e1ca4e3a380ef3e8f46ce006f1146392e3f32c98 cve-icon cve-icon
History

Sun, 18 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-190
CWE-788

Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: squashfs: Add dictionary size range check to prevent shift-out-of-bounds When an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size is 0) is mounted, and performs shift operations using dictionarysize, the shift exponent is -1, causing a shift-out-of-bounds. Detail as below: squashfs_comp_opts(msblk, buffer, length) squashfs_xz_comp_opts() if (comp_opts) n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + (1 << (n + 1))) <----shift-out-of-bounds Fix it by adding a dictionary size range check before the shift operation.
Title squashfs: Add dictionary size range check to prevent shift-out-of-bounds
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-18T15:20:07.184Z

Reserved: 2026-09-25T10:25:14.361Z

Link: CVE-2026-98636

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:16.700

Modified: 2026-10-18T16:17:16.700

Link: CVE-2026-98636

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T18:15:15Z

Weaknesses