CVE-2026-64052 block: bio-integrity: Fix null-ptr-deref in bio_integrity_map_user()
A local attacker can trigger a kernel crash via a null pointer dereference in the block integrity subsystem when user pages are partially pinned.
- 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-2026-64052?
CVE-2026-64052 is a medium-severity vulnerability in Linux kernel, published on 19 Jul 2026. 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:
block: bio-integrity: Fix null-ptr-deref in bio_integrity_map_user()
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0.
To fix this, add a check to verify that all requested memory is pinned. If partial pinning occurs, unpin the memory and return -EFAULT.
Kernel Oops:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6
Weakness: CWE-476
Which versions are affected by CVE-2026-64052?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64052?
Apply the vendor's patch.
Is CVE-2026-64052 being exploited?
There is no known exploitation of CVE-2026-64052 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64052, DEBIAN-CVE-2026-64052, GHSA-f89w-gg6r-rvww, UBUNTU-CVE-2026-64052.