CVE-2026-89525 in Linux
요약
\~에 의해 MITRE • 2026. 09. 12.
In the Linux kernel, the following vulnerability has been resolved:
udf: reject VAT indexes equal to the entry count
UDF 1.50 virtual partition mapping uses the VAT as an array of physical block mappings. s_num_entries stores the number of entries in that array, not the highest valid index. The valid VAT indexes are therefore below s_num_entries.
udf_get_pblock_virt15() currently rejects only indexes greater than s_num_entries. A crafted image can request index s_num_entries, pass the bounds check, and make the kernel read one entry past the allocated VAT table.
Change the check to reject block >= s_num_entries, so the count is handled as an exclusive upper bound.
A crafted UDF image reproduced this on origin/master commit 0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds report in udf_get_pblock_virt15().
Trail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed.
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