CVE-2026-31567PM: sleep: Drop spurious WARN_ON() from pm_restore_gfp_mask()

Official description

In the Linux kernel, the following vulnerability has been resolved: PM: sleep: Drop spurious WARN_ON() from pm_restore_gfp_mask() Commit 35e4a69b2003f ("PM: sleep: Allow pm_restrict_gfp_mask() stacking") introduced refcount-based GFP mask management that warns when pm_restore_gfp_mask() is called with saved_gfp_count == 0. Some hibernation paths call pm_restore_gfp_mask() defensively where the GFP mask may or may not be restricted depending on the execution path. For example, the uswsusp interface invokes it in SNAPSHOT_CREATE_IMAGE, SNAPSHOT_UNFREEZE, and snapshot_release(). Before the stacking change this was a silent no-op; it now triggers a spurious WARNING. Remove the WARN_ON() wrapper from the !saved_gfp_count check while retaining the check itself, so that defensive calls remain harmless without producing false warnings. [ rjw: Subject tweak ]

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/3025ca5daa9d682b629c0c958b538e41deeb559d
• https://git.kernel.org/stable/c/f19d1323aa3dd7ead469aef47d9085f8939565d9
• https://git.kernel.org/stable/c/a8d51efb5929ae308895455a3e496b5eca2cd143