CVE-2026-63907: uio: uio_pci_generic_sva: fix double free of devm_kzalloc() memory
High 7.8 EPSS 0.2% Linux kernel
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.
- CVE-2026-63907CVE identifier
- 7.8CVSS 3.1 base score (high)
- 0.2%EPSS: chance of exploitation in the next 30 days (higher than 5% of CVEs)
- 2026-07-19published
What do these terms mean? CVE · CVSS score · exploited (KEV) · EPSS · backported fix · all terms
What to do now
- Check whether you run Linux kernel and which version (commands below).
- Install the fixed version for your system: see “Patch it” below.
- Reboot into the new kernel (uname -r to confirm); live patching (kpatch, Ubuntu Livepatch, SUSE kGraft/klp) can defer the reboot for some CVEs
Affected and fixed versions
Affected:
- Linux Linux 3397c3cd859a2c51962ad032dcf97961d42f9db2 to before e344865bfca4eb37ed8d7ac5917226e49fcec7ce
- Linux Linux 3397c3cd859a2c51962ad032dcf97961d42f9db2 to before f74c8696f14149d5e43cc28b015326a759c48f00
- Linux Linux 6.19
Patch it
Use the commands for your system. Distribution packages often keep an older version number with the fix backported, so compare with the fixed package versions in the table below, not only with the upstream version.
Debian
sudo apt update
sudo apt install --only-upgrade linux-image-amd64Ubuntu
sudo apt update
sudo apt install --only-upgrade linux-image-generic (or the installed flavour: linux-image-aws, -azure, -gcp, -virtual)RHEL, AlmaLinux, Rocky, Oracle
sudo dnf upgrade --refresh kernelFedora
sudo dnf upgrade --refresh kernelSUSE / openSUSE
sudo zypper refresh
sudo zypper update kernel-defaultAmazon Linux
sudo dnf upgrade --releasever=latest kernel kernel6.12Arch Linux
sudo pacman -SyuAlpine
apk update && apk upgrade linux-lts linux-virtFreeBSD
not LinuxGeneral update steps for every system are on the Linux and Unix & BSD pages; after updating, see which services to restart.
Fix status in Linux distributions
| Release | Package | Status | Fixed version / advisory |
|---|---|---|---|
| Debian 12 | linux | not affected | |
| Debian 13 | linux | not affected | |
| Debian testing | linux | fixed | 7.0.12-1 |
From the Debian security tracker, Ubuntu CVE tracker and Red Hat Security Data API, refreshed every few hours.
Sources
- https://git.kernel.org/stable/c/e344865bfca4eb37ed8d7ac5917226e49fcec7ce
- https://git.kernel.org/stable/c/f74c8696f14149d5e43cc28b015326a759c48f00
- CVE-2026-63907 on CVE.org
- CVE-2026-63907 on NVD
Page generated automatically from official sources on 2026-11-03 18:05 UTC. Always confirm with your vendor's advisory.