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CVE-2026-64322 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: udf: validate sparing table length as an entry count, not a byte count udf_load_sparable_map() accepts a sparing table when sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize is false, i.e. it treats reallocationTableLen as a number of BYTES that must fit in the block. But the table is walked as an array of 8-byte sparingEntry elements: for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) { struct sparingEntry *entry = &st->mapEntry[i]; ... entry->origLocation ... } in udf_get_pblock_spar15() and udf_relocate_blocks(). A reallocationTableLen of N therefore passes the check whenever sizeof(*st) + N <= blocksize, yet the consumers index sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the block. On a crafted UDF image this is an out-of-bounds read in udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the same length to udf_update_tag(), whose crc_itu_t() reads far past the block, and its memmove() through st->mapEntry[] is an out-of-bounds write. Validate reallocationTableLen as the entry count it is, with struct_size().


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-64322
NVD Published Date:
07/25/2026
NVD Last Modified:
07/25/2026
Source:
kernel.org