PT-2026-64545 · Linux · Linux
CVE-2026-64324
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Published
2026-07-25
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Updated
2026-07-25
None
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In the Linux kernel, the following vulnerability has been resolved:
udf: validate free block extents against the partition length
udf free blocks() checks the logical block number and count against the
partition length, but drops the extent offset from that final bound. A
crafted extent can pass the guard while logicalBlockNum + offset + count
points past the partition, which later indexes past the space bitmap
array.
A single ftruncate(2) on a file backed by such an extent reliably
panics the kernel. This is a local availability issue. On desktop
systems where UDisks/polkit allows the active user to mount removable
UDF media without CAP SYS ADMIN, an unprivileged local user can supply
the crafted filesystem and trigger the panic by truncating a writable
file on it. Systems that require root or CAP SYS ADMIN to mount the
image have a higher prerequisite.
No confidentiality or integrity impact is claimed: the reproduced
primitive is an out-of-bounds read of a bitmap pointer slot followed by
a kernel panic.
Use the already computed logicalBlockNum + offset + count value for the
partition length check. Also make load block bitmap() reject an
out-of-range block group before indexing s block bitmap[], so corrupted
callers cannot walk past the flexible array.
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Related Identifiers
Affected Products
Linux