CVE-2026-45991 PUBLISHED

udf: fix partition descriptor append bookkeeping

Assigner: Linux
Reserved: 13.05.2026 Published: 27.05.2026 Updated: 27.05.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from ee4af50ca94f58afc3532662779b9cf80bbe27c8 to 058b451b1039f056d1362c4fec2229e522366ab0 (excl.)
  • affected from ee4af50ca94f58afc3532662779b9cf80bbe27c8 to b5597bb83fc37b5b5da74a4453fa920b932cf39a (excl.)
  • affected from ee4af50ca94f58afc3532662779b9cf80bbe27c8 to 08fa5d818e5bf53c7ca234d88ba334f32004e9b6 (excl.)
  • affected from ee4af50ca94f58afc3532662779b9cf80bbe27c8 to 08841b06fa64d8edbd1a21ca6e613420c90cc4b8 (excl.)
  • Version 7f401f160a9c7a1ff84ba3cb9b2f636d1f5cfb6b is affected
  • affected from 4.18.7 to 4.19 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.19 is affected
  • unaffected from 0 to 4.19 (excl.)
  • unaffected from 6.6.140 to 6.6.* (incl.)
  • unaffected from 6.12.88 to 6.12.* (incl.)
  • unaffected from 7.0.4 to 7.0.* (incl.)
  • unaffected from 7.1-rc1 to * (incl.)

References