Bug 2466999 (CVE-2026-43076) - CVE-2026-43076 kernel: ocfs2: validate inline data i_size during inode read
Summary: CVE-2026-43076 kernel: ocfs2: validate inline data i_size during inode read
Keywords:
Status: NEW
Alias: CVE-2026-43076
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-06 10:02 UTC by OSIDB Bzimport
Modified: 2026-05-06 14:33 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-05-06 10:02:32 UTC
In the Linux kernel, the following vulnerability has been resolved:

ocfs2: validate inline data i_size during inode read

When reading an inode from disk, ocfs2_validate_inode_block() performs
various sanity checks but does not validate the size of inline data.  If
the filesystem is corrupted, an inode's i_size can exceed the actual
inline data capacity (id_count).

This causes ocfs2_dir_foreach_blk_id() to iterate beyond the inline data
buffer, triggering a use-after-free when accessing directory entries from
freed memory.

In the syzbot report:
  - i_size was 1099511627576 bytes (~1TB)
  - Actual inline data capacity (id_count) is typically <256 bytes
  - A garbage rec_len (54648) caused ctx->pos to jump out of bounds
  - This triggered a UAF in ocfs2_check_dir_entry()

Fix by adding a validation check in ocfs2_validate_inode_block() to ensure
inodes with inline data have i_size <= id_count.  This catches the
corruption early during inode read and prevents all downstream code from
operating on invalid data.


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