CVE-2026-89525 — udf: reject VAT indexes equal to the entry count
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 arra…
Published: 2026-09-11 · CVSS: Unscored
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7