CVE-2026-45991

Summary

In the Linux kernel, the following vulnerability has been resolved:

udf: fix partition descriptor append bookkeeping

Mounting a crafted UDF image with repeated partition descriptors can trigger a heap out-of-bounds write in part_descs_loc[].

handle_partition_descriptor() deduplicates entries by partition number, but appended slots never record partnum. As a result duplicate Partition Descriptors are appended repeatedly and num_part_descs keeps growing.

Once the table is full, the growth path still sizes the allocation from partnum even though inserts are indexed by num_part_descs. If partnum is already aligned to PART_DESC_ALLOC_STEP, ALIGN(partnum, step) can keep the old capacity and the next append writes past the end of the table.

Store partnum in the appended slot and size growth from the next append count so deduplication and capacity tracking follow the same model.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < ad3c0c4400686f6f37b382aaa48fac2b9aefccbeaffected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < 68013a9bd4c01acd42073715f00e1a1992f089eeaffected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < e8474cfbac9ada2cdaa4eaedec22aadfa0f58559affected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < 058b451b1039f056d1362c4fec2229e522366ab0affected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < b5597bb83fc37b5b5da74a4453fa920b932cf39aaffected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < 08fa5d818e5bf53c7ca234d88ba334f32004e9b6affected
LinuxLinuxee4af50ca94f58afc3532662779b9cf80bbe27c8 < 08841b06fa64d8edbd1a21ca6e613420c90cc4b8affected
LinuxLinux7f401f160a9c7a1ff84ba3cb9b2f636d1f5cfb6baffected
LinuxLinux4.18.7 < 4.19affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux5.10.259 <= 5.10.*unaffected
LinuxLinux5.15.210 <= 5.15.*unaffected
LinuxLinux6.1.176 <= 6.1.*unaffected
LinuxLinux6.6.140 <= 6.6.*unaffected
LinuxLinux6.12.88 <= 6.12.*unaffected
LinuxLinux7.0.4 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References