Bug 2482148 (CVE-2026-46094)

Summary: CVE-2026-46094 kernel: ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's ext4 filesystem, specifically in the `check_xattrs()` function. A local attacker could exploit a bounds check error, allowing an out-of-bounds read when processing extended attributes (xattrs). This could lead to memory corruption, potentially causing a denial of service or information disclosure.
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Description OSIDB Bzimport 2026-05-27 15:13:36 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access

The bounds check for the next xattr entry in check_xattrs() uses
(void *)next >= end, which allows next to point within sizeof(u32)
bytes of end. On the next loop iteration, IS_LAST_ENTRY() reads 4
bytes via *(__u32 *)(entry), which can overrun the valid xattr region.

For example, if next lands at end - 1, the check passes since
next < end, but IS_LAST_ENTRY() reads 4 bytes starting at end - 1,
accessing 3 bytes beyond the valid region.

Fix this by changing the check to (void *)next + sizeof(u32) > end,
ensuring there is always enough space for the IS_LAST_ENTRY() read
on the subsequent iteration.
Comment 1 Keith Grant 2026-05-27 16:56:18 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052703-CVE-2026-46094-7344@gregkh/T