CVE-2025-38451 md/md-bitmap: fix GPF in bitmap_get_stats()
A local attacker can cause a kernel crash by reading bitmap stats, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38451?
CVE-2025-38451 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-38451?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38451?
Apply the vendor's patch.
Is CVE-2025-38451 being exploited?
There is no known exploitation of CVE-2025-38451 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-38451, DEBIAN-CVE-2025-38451, GHSA-63cx-f5q6-6hg2, ROOT-OS-DEBIAN-12-CVE-2025-38451, UBUNTU-CVE-2025-38451.