Re: [BUG] rcu: stall detected in sys_mmap with PREEMPT(full) involving timer softirq and DRM vblank disable

[Matthew Wilcox]

On Wed, Jan 07, 2026 at 01:52:11PM +0800, 王志 wrote:
> Hello,
> 
> I am reporting an RCU stall detected during syzkaller-style fuzz testing.
> The stall is reported while executing sys_mmap(), with the
> rcu_preempt grace-period kthread starved for over 10 seconds. The
> observed stacks involve memory fault handling, timer softirq processing,
> and DRM vblank disable paths. With PREEMPT(full) enabled, the RCU grace
> period fails to complete.

Get your changes into syzkaller upstream, don't spam us with "i'm doing
syzbot's job".