CVE-2026-45991

udf: fix partition descriptor append bookkeeping

State: Published
Severity: 7.8 High
Published: May 27, 2026
Updated: Oct 19, 2026
Reserved: May 13, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-787 Out-of-bounds Write

Affected Products

Product	Versions
LinuxLinux	ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before ad3c0c4400686f6f37b382aaa48fac2b9aefccbeAffected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 68013a9bd4c01acd42073715f00e1a1992f089eeAffected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before e8474cfbac9ada2cdaa4eaedec22aadfa0f58559Affected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 058b451b1039f056d1362c4fec2229e522366ab0Affected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before b5597bb83fc37b5b5da74a4453fa920b932cf39aAffected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 73df74544b55241dca5dd788523e6f5f10bd2b9bAffected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 08fa5d818e5bf53c7ca234d88ba334f32004e9b6Affected ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 08841b06fa64d8edbd1a21ca6e613420c90cc4b8Affected 7f401f160a9c7a1ff84ba3cb9b2f636d1f5cfb6bAffected 4.18.7 to before 4.19Affected
LinuxLinux	4.19Affected before 4.19Not affected 5.10.259 through 5.10.Not affected 5.15.210 through 5.15.Not affected 6.1.176 through 6.1.Not affected 6.6.140 through 6.6.Not affected 6.12.88 through 6.12.Not affected 6.18.57 through 6.18.Not affected 7.0.4 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before ad3c0c4400686f6f37b382aaa48fac2b9aefccbeAffected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 68013a9bd4c01acd42073715f00e1a1992f089eeAffected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before e8474cfbac9ada2cdaa4eaedec22aadfa0f58559Affected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 058b451b1039f056d1362c4fec2229e522366ab0Affected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before b5597bb83fc37b5b5da74a4453fa920b932cf39aAffected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 73df74544b55241dca5dd788523e6f5f10bd2b9bAffected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 08fa5d818e5bf53c7ca234d88ba334f32004e9b6Affected
ee4af50ca94f58afc3532662779b9cf80bbe27c8 to before 08841b06fa64d8edbd1a21ca6e613420c90cc4b8Affected
7f401f160a9c7a1ff84ba3cb9b2f636d1f5cfb6bAffected
4.18.7 to before 4.19Affected

LinuxLinux

4.19Affected
before 4.19Not affected
5.10.259 through 5.10.*Not affected
5.15.210 through 5.15.*Not affected
6.1.176 through 6.1.*Not affected
6.6.140 through 6.6.*Not affected
6.12.88 through 6.12.*Not affected
6.18.57 through 6.18.*Not affected
7.0.4 through 7.0.*Not affected
7.1 and laterNot affected

References

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