Re: [PATCH v2] rseq: fix using an uninitialized stack variable in rseq_exit_user_update

[Tetsuo Handa]

On 2026/06/02 19:42, Peter Zijlstra wrote:
> On Tue, Jun 02, 2026 at 11:08:54AM +0800, Qing Wang wrote:
>> There is an bug which is an uninitialized stack variable use in
>> `rseq_exit_user_update()` reported by syzbot:
>>
>> BUG: KMSAN: kernel-infoleak in rseq_set_ids_get_csaddr include/linux/rseq_entry.h:502 [inline]
>>
>> The local variable:
>> ```c
>> 	struct rseq_ids ids = {
>> 		.cpu_id	 = task_cpu(t),
>> 		.mm_cid	 = task_mm_cid(t),
>> 		.node_id = cpu_to_node(ids.cpu_id),
>> 	};
>> ```
> 
> FWIW, I've no idea what that ``` nonsense is, but it does not belong in
> Changelogs. I've removed it.
> 

It seems that this problem is still happening after
commit 6d99479799c6 ("rseq: Fix using an uninitialized stack variable
in rseq_exit_user_update()") was applied. Please check.