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CVE-2026-90203NVD
Vulnerability Summary
In the Linux kernel, the following vulnerability has been resolved:
Squashfs: check block offset is not negative
If a negative offset is read off disk (for example the offset into the
decompressed fragment block), this will cause squashfs_copy_data() to
perform an out of bounds access.
Fix by checking if offset is negative, and returning 0. This matches
existing behaviour where an offset beyond the block returns 0 bytes
copied.
To trigger this out of bounds access requires a crafted Squashfs
filesystem and CAP_SYS_ADMIN to mount it. Unprivileged users will not be
able to mount such a filesystem, but once mounted, an unprivileged user
can trigger the out of bounds access by reading the crafted file with the
negative offset.
Squashfs: check block offset is not negative
If a negative offset is read off disk (for example the offset into the
decompressed fragment block), this will cause squashfs_copy_data() to
perform an out of bounds access.
Fix by checking if offset is negative, and returning 0. This matches
existing behaviour where an offset beyond the block returns 0 bytes
copied.
To trigger this out of bounds access requires a crafted Squashfs
filesystem and CAP_SYS_ADMIN to mount it. Unprivileged users will not be
able to mount such a filesystem, but once mounted, an unprivileged user
can trigger the out of bounds access by reading the crafted file with the
negative offset.
CVSS v3.1 Base Metrics — Score 7.1 (HIGH)
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityHigh
Affected & Patched Versions
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < b169185d5c672b989985c6c2e38cafab2548ba88
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < c2a126fca820ae74872da28de68dc74d4595dc4b
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < 95dadf366c117dcdca78a570e6832071deab1ecd
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < 3d2f0cb66c909ea2312cdef465165bb9a3ba2d84
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < bbb2218eb072b0a15dc063929200183bd23c2344
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < d0a3729d464fcf516416a41cf304c0c92126ee03
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe
- Linux Linux >= f400e12656ab518be107febfe2315fb1eab5a342 and < e300eb5002925b29be803d2661af07266cfa267e
- Linux Linux >= 2.6.29
- Linux Linux b169185d5c672b989985c6c2e38cafab2548ba88
- Linux Linux c2a126fca820ae74872da28de68dc74d4595dc4b
- Linux Linux 95dadf366c117dcdca78a570e6832071deab1ecd
- Linux Linux 3d2f0cb66c909ea2312cdef465165bb9a3ba2d84
- Linux Linux bbb2218eb072b0a15dc063929200183bd23c2344
- Linux Linux d0a3729d464fcf516416a41cf304c0c92126ee03
- Linux Linux e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe
- Linux Linux e300eb5002925b29be803d2661af07266cfa267e
External References
- https://git.kernel.org/stable/c/b169185d5c672b989985c6c2e38cafab2548ba88
- https://git.kernel.org/stable/c/c2a126fca820ae74872da28de68dc74d4595dc4b
- https://git.kernel.org/stable/c/95dadf366c117dcdca78a570e6832071deab1ecd
- https://git.kernel.org/stable/c/3d2f0cb66c909ea2312cdef465165bb9a3ba2d84
- https://git.kernel.org/stable/c/bbb2218eb072b0a15dc063929200183bd23c2344
- https://git.kernel.org/stable/c/d0a3729d464fcf516416a41cf304c0c92126ee03
- https://git.kernel.org/stable/c/e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe
- https://git.kernel.org/stable/c/e300eb5002925b29be803d2661af07266cfa267e