Description
In the Linux kernel, the following vulnerability has been resolved:
uprobes: Fix NULL pointer dereference in hprobe_expire()
Forking a task that has a pending uretprobe can oops the kernel with a NULL pointer dereference in the clone() path:
BUG: kernel NULL pointer dereference, address: 0000000000000018 Oops: 0002 [#1] SMP NOPTI RIP: 0010:hprobe_expire CR2: 0000000000000018 Call Trace: uprobe_copy_process copy_process kernel_clone __x64_sys_clone do_syscall_64 entry_SYSCALL_64_after_hwframe
This was found on real hosts on Meta fleet.
I've got the impression that this is what is happening:
CPU 1 CPU 2 (traced task) ----- ------------------- hit uprobe, prepare_uretprobe(): hprobe LEASED, refcount >= 1 uprobe_unregister() put_uprobe(): refcount -> 0 fork() -> dup_utask() hprobe_expire(hprobe, true) try_get_uprobe() -> NULL get_uprobe(NULL) <-- Oops
Only take the extra reference when the uprobe is non-NULL; a NULL means it is gone and is the correct value to return.
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Aug 15, 2026
- Last modified
- Aug 17, 2026
- NVD status
- Received