Bug 2516550 (CVE-2026-72471) - CVE-2026-72471 kernel: fs/ntfs3: prevent potential lcn remains uninitialized
Summary: CVE-2026-72471 kernel: fs/ntfs3: prevent potential lcn remains uninitialized
Keywords:
Status: NEW
Alias: CVE-2026-72471
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:18 UTC by OSIDB Bzimport
Modified: 2026-08-18 15:34 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-08-15 06:18:25 UTC
In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: prevent potential lcn remains uninitialized

The target VCN being sought was not found within runs[0], causing
run_lookup() to return false. This causes run_lookup_entry() to return
false, which in turn results in a len value of 0, and the new parameter
passed to attr_data_get_block() is NULL. Collectively, these factors
ultimately cause attr_data_get_block_locked() to exit prematurely without
initializing lcn, thereby triggering [1].

To prevent [1], the clen check within ni_seek_data_or_hole() has been
moved to occur before the lcn check.

[1]
BUG: KMSAN: uninit-value in ni_seek_data_or_hole+0x24f/0x5f0 fs/ntfs3/frecord.c:2862
 ni_seek_data_or_hole+0x24f/0x5f0 fs/ntfs3/frecord.c:2862
 ntfs_llseek+0x22a/0x4a0 fs/ntfs3/file.c:1530
 vfs_llseek fs/read_write.c:391 [inline]


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