CVE-2026-74477

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/3bd35a5e272a1b7a3fb43acad9bdc599281b13fa ↗
• https://git.kernel.org/stable/c/06c275a6c0a953ef1d763d11a6891fcc69ae2ac0 ↗
• https://git.kernel.org/stable/c/cc679d7a6303e84d769f2afcde1fc51c51f127cd ↗