CVE-2026-63907 uio: uio_pci_generic_sva: fix double free of devm_kzalloc() memory
A double free vulnerability in the Linux kernel's uio_pci_generic_sva driver allows local attackers to cause a denial of service or potentially execute code.
- 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-2026-63907?
CVE-2026-63907 is an use after free vulnerability in Linux, 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:
uio: uio_pci_generic_sva: fix double free of devm_kzalloc() memory
uio_pci_sva allocates struct uio_pci_sva_dev with devm_kzalloc() in probe(), but then calls kfree(udev) both on the probe() error path (label out_free) and again in remove().
Because devm_kzalloc() allocations are devres-managed and are freed automatically when the device is detached (including after a failing probe() and during driver unbind), the explicit kfree() can lead to a double free.
If probe() fails after devm_kzalloc(), the error path frees udev and devres cleanup will free it again when the core unwinds the partially bound device. On normal driver removal, remove() frees udev and devres will free it again when the device is detached.
This issue was identified by a static analysis tool I developed and confirmed by manual review. Fix by removing the manual kfree() calls and dropping the now-unused label.
Which versions are affected by CVE-2026-63907?
How do I fix CVE-2026-63907?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-63907 being exploited?
There is no known exploitation of CVE-2026-63907 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-63907, GHSA-g9q5-69g8-2q3f, UBUNTU-CVE-2026-63907.