Race Condition in Linux Kernel Keyring Restriction Handling

CVE-2026-99245

What is CVE-2026-99245?

The Linux kernel contains a vulnerability in the handling of keyring restrictions. The issue arises within the key_reject_and_link() function, where a check for keyring restrictions occurs prior to acquiring the keyring semaphore. This can lead to a race condition with concurrent operations that modify the keyring, potentially allowing unauthorized access to sensitive keyring operations. The fix involves reordering the check to occur after acquiring the semaphore, ensuring that it operates safely within the expected locking protocol.

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