CVE-2025-38451

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

md/md-bitmap: fix GPF in bitmap_get_stats()

The commit message of commit 6ec1f0239485 (md/md-bitmap: fix stats collection for external bitmaps) states:

Remove the external bitmap check as the statistics should be
available regardless of bitmap storage location.

Return -EINVAL only for invalid bitmap with no storage (neither in
superblock nor in external file).

But, the code does not adhere to the above, as it does only check for a valid super-block for internal bitmaps. Hence, we observe:

Oops: GPF, probably for non-canonical address 0x1cd66f1f40000028 RIP: 0010:bitmap_get_stats+0x45/0xd0 Call Trace:

seq_read_iter+0x2b9/0x46a seq_read+0x12f/0x180 proc_reg_read+0x57/0xb0 vfs_read+0xf6/0x380 ksys_read+0x6d/0xf0 do_syscall_64+0x8c/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

We fix this by checking the existence of a super-block for both the internal and external case.

Affected Software

References

• https://git.kernel.org/stable/c/3d82a729530bd2110ba66e4a1f73461c776edec2
• https://git.kernel.org/stable/c/3e0542701b37aa25b025d8531583458e4f014c2e
• https://git.kernel.org/stable/c/a18f9b08c70e10ea3a897058fee8a4f3b4c146ec
• https://git.kernel.org/stable/c/a23b16ba3274961494f5ad236345d238364349ff
• https://git.kernel.org/stable/c/c17fb542dbd1db745c9feac15617056506dd7195