CVE-2026-98636

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.