CVE-2026-74379 dax/kmem: account for partial discontiguous resource upon removal
A null pointer dereference in the Linux kernel DAX/kmem driver can cause a system crash during device removal if partial memory mapping fails.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74379?
CVE-2026-74379 is a vulnerability in Linux, published on 15 Aug 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:
dax/kmem: account for partial discontiguous resource upon removal
When dev_dax_kmem_probe() partially succeeds (at least one range is mapped) but a subsequent range fails request_mem_region() or add_memory_driver_managed(), the probe silently continues, ultimately returning success, but with the corresponding range resource NULL'ed out.
dev_dax_kmem_remove() iterates over all dax_device ranges regardless of if the underlying resource exists. When remove_memory() is called later, it returns 0 because the memory was never added which causes dev_dax_kmem_remove() to incorrectly assume the (nonexistent) resource can be removed and attempts cleanup on a NULL pointer.
Fix this by skipping these ranges altogether, noting that these cases are considered success, such that the cleanup is still reached when all actually-added ranges are successfully removed.
Which versions are affected by CVE-2026-74379?
How do I fix CVE-2026-74379?
Apply the vendor's patch.
Is CVE-2026-74379 being exploited?
There is no known exploitation of CVE-2026-74379 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74379, DEBIAN-CVE-2026-74379, GHSA-wpc6-x34r-qgj2, UBUNTU-CVE-2026-74379.