Linux PCI sysfs: BAR resize via resourceN_resize had no CAP_SYS_ADMIN check

UnscoredCVE-2026-97505Kernel, userspace & hypervisorcurated

Impact

Writing the resourceN_resize sysfs attribute reprograms a PCI device's BAR size, and the kernel gated it only on file permissions rather than on CAP_SYS_ADMIN. Anyone who could open that file for writing could change the BAR layout of a live device and disrupt the driver bound to it. That matters on GPU and DPU nodes because resizable BARs are exactly what large-VRAM accelerators and NICs use, and a resize under an active driver is a device-level disruption that typically ends in a node reboot, not a clean recovery. In practice the sysfs file is root-owned on a default system, so exposure depends on whether anything in your stack loosens those permissions or hands the file to a less privileged agent.

Who can reach it

Local, and only for a user or container that has been given write access to /sys/bus/pci/devices/*/resourceN_resize. Default permissions already restrict this to root, so this is a defence-in-depth fix for hosts where sysfs ownership has been relaxed.

What to do

Pick up a stable kernel with the CAP_SYS_ADMIN check (three stable commits listed) on your next kernel roll and reboot the node. In the meantime confirm nothing but root can write PCI resize attributes on your hosts - that check costs nothing and closes the reachable case. No fixed distro version is named in the record.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-97505 https://git.kernel.org/stable/c/25ec7f57deceec633f27bc93b615f951e2ade814 https://git.kernel.org/stable/c/b722a607f858b9cd036075ea0efad553fb98e982 https://git.kernel.org/stable/c/cbf0628c0b7db86c5ce36451f088101546acbf1d

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.