fs/ntfs3: bound page_lcns[] index by the log record

Overview

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

fs/ntfs3: bound page_lcns[] index by the log record

The copy_lcns loop and the redo shorten loop index page_lcns[] at j + i, where i runs up to the log record's lcns_follow. That count is checked only against the record's own length, not the target entry, so check_dp_table() (which validates the entry's lcns_follow) does not cover it: the copy_lcns entry may even be freshly allocated after that check, and find_dp() bounds j but not i. A crafted record thus overflows page_lcns[] of an otherwise valid entry.

Add dp_range_ok() and reject, before each loop, any record whose run does not fit the entry. These are the only two page_lcns[] accesses indexed by the record rather than the entry, so together with the entry validation every access is now bounded.

[[email protected]: original patch contained changes to the problem already handled, applied partly]

Affected

• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 31fdd11f75da9823500168cecb07aa45130915a3
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < bb742d1030864c0fe140666f639428ba4e90b2ca
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 61ca8cbbf68f77f25b699ed4358bd232f94ed43b
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < f4c1bc6d7331f344ffcea93c2a37badcbe15baa6
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 7ccb94901f38a062034b56b43c774050b113758f
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 1135ebc225996b3ac1a295652b19a0a706737a6c
• Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 6f7b9dbdc1b7520206abce0049bdd143eb536e75
• Linux 5.15

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · updated 2026-09-18 · vex