Executive brief
A vulnerability was identified in the Linux kernel's power sequencing subsystem that could lead to system instability. The issue occurs when the system attempts to access information about power devices through a specific diagnostic interface (debugfs). An exploit could cause the system to crash or behave unpredictably, potentially impacting the availability of the server or device.
Technical details
A use-after-free (UAF) vulnerability exists in drivers/power/sequencing/core.c within the pwrseq_debugfs_seq_next() function. The root cause is an incorrect use of the __free(put_device) macro, which prematurely drops a device reference before the seq_file framework has finished using the pointer. An attacker with local access to debugfs could trigger this UAF, leading to kernel memory corruption or a denial-of-service (kernel oops). The fix involves implementing consistent reference counting across the start(), next(), and stop() seq_file callbacks to ensure device pointers remain valid during iteration.
Affected products
- Linux Linux Kernel 6.11, 6.12, 6.18, 7.1
Timeline
- 2026-06-16: disclosed: Initial patch submitted by Wentao Liang
- 2026-07-24: advisory: CVE-2026-64251 published in NVD