CVE-2026-43076

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/d012c782abcabe68b5b9e71be58a15e9f9d83dc1
• https://git.kernel.org/stable/c/bcd46bc261b215b3b12c557a978299eafa02ecdd
• https://git.kernel.org/stable/c/131c0b573e1b467b7d553e9ff38003f1acd8f5f2
• https://git.kernel.org/stable/c/37f074e65f24f10f8d8df224a572e4cb9e6faf63
• https://git.kernel.org/stable/c/c1de19e891be3bfb3e1d0c7cf07bbb8fb3b77c1b
• https://git.kernel.org/stable/c/cd2d765aa7157f852999842af32148128c735d39
• https://git.kernel.org/stable/c/77d0295725109d77f5854ef5b58c0d06c08168cc
• https://git.kernel.org/stable/c/1524af3685b35feac76662cc551cbc37bd14775f

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