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CVE-2026-31716

fs/ntfs3: validate rec->used in journal-replay file record check PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate rec->used in journal-replay file record check check_file_record() validates rec->total against the record size but never validates rec->used. The do_action() journal-replay handlers read rec->used from disk and use it to compute memmove lengths: DeleteAttribute: memmove(attr, ..., used - asize - roff) CreateAttribute: memmove(..., attr, used - roff) change_attr_size: memmove(..., used - PtrOffset(rec, next)) When rec->used is smaller than the offset of a validated attribute, or larger than the record size, these subtractions can underflow allowing us to copy huge amounts of memory in to a 4kb buffer, generally considered a bad idea overall. This requires a corrupted filesystem, which isn't a threat model the kernel really needs to worry about, but checking for such an obvious out-of-bounds value is good to keep things robust, especially on journal replay Fix this up by bounding rec->used correctly. This is much like commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") which checked different values in this same switch statement.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected b46acd6a6a627d876898e1c84d3f84902264b445 before 8e64d33198b5a0fb14a452708bad844f94f03b2c; affected b46acd6a6a627d876898e1c84d3f84902264b445 before 1393a467a9607e62123806de7d4c3a3e54e396a9; affected b46acd6a6a627d876898e1c84d3f84902264b445 before f90b8a1798b750755a9e9aee66678f0a1820bbaf; affected b46acd6a6a627d876898e1c84d3f84902264b445 before 4b1613d7e2deda831a97e427d1ea586e50fe1be5; affected b46acd6a6a627d876898e1c84d3f84902264b445 before 0112e6279420d4005b3d57af36fb45c01b8d0116; affected b46acd6a6a627d876898e1c84d3f84902264b445 before f79d0403ea20a81bc29105bba54fbcab54e8c403; affected b46acd6a6a627d876898e1c84d3f84902264b445 before 0ca0485e4b2e837ebb6cbd4f2451aba665a03e4b
Linux / Linuxaffected 5.15; unaffected 0 before 5.15; unaffected 5.15.209 through 5.15.*; unaffected 6.1.175 through 6.1.*; unaffected 6.6.136 through 6.6.*; unaffected 6.12.84 through 6.12.*; unaffected 6.18.25 through 6.18.*; unaffected 7.0.2 through 7.0.*; unaffected 7.1 through *

CWE

No CWE identifiers supplied.

References