On Tue, Mar 31, 2020 at 11:57 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Mon, Mar 30, 2020 at 10:01:12PM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: 9420e8ad Merge tag 'for-linus' of git://git.kernel.org/pub.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=1206ed4be00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=27392dd2975fd692 > > dashboard link: https://syzkaller.appspot.com/bug?extid=e84d7ebd1361da13c356 > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+e84d7ebd1361da13c356@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > INFO: trying to register non-static key. > > the code is fine but needs lockdep annotation. > > turning off the locking correctness validator. > > CPU: 1 PID: 1014 Comm: syz-executor.0 Not tainted 5.6.0-rc7-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > Call Trace: > > <IRQ> > > __dump_stack lib/dump_stack.c:77 [inline] > > dump_stack+0x188/0x20d lib/dump_stack.c:118 > > assign_lock_key kernel/locking/lockdep.c:880 [inline] > > register_lock_class+0x14c4/0x1540 kernel/locking/lockdep.c:1189 > > __lock_acquire+0xfc/0x3ca0 kernel/locking/lockdep.c:3836 > > lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484 > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 > > try_to_wake_up+0x9f/0x17c0 kernel/sched/core.c:2547 > > That's p->pi_lock, which gets initialized in rt_mutex_init_task() in > copy_process(). This should be impossible. Very odd. The stack mentions fbdev, which is a red flag at the moment. There are a dozen of bad bugs in fbdev and around. Just few days ago Andy pointed to another "impossible" crash "general protection fault in do_syscall_64" which is related to dri: https://syzkaller.appspot.com/bug?id=0ec7b2602b1ff40f0d34f38baa4ba1640727c3d9 https://groups.google.com/forum/#!msg/syzkaller-bugs/ePqhfYx0-8M/Q_Urt97iAAAJ There are probably more random manifestations of these bugs already, and I guess we will be getting more. +fbdev maintainers > > wake_up_worker kernel/workqueue.c:836 [inline] > > insert_work+0x2ad/0x3a0 kernel/workqueue.c:1337 > > __queue_work+0x50d/0x1280 kernel/workqueue.c:1488 > > call_timer_fn+0x195/0x760 kernel/time/timer.c:1404 > > expire_timers kernel/time/timer.c:1444 [inline] > > __run_timers kernel/time/timer.c:1773 [inline] > > __run_timers kernel/time/timer.c:1740 [inline] > > run_timer_softirq+0x412/0x1600 kernel/time/timer.c:1786 > > __do_softirq+0x26c/0x99d kernel/softirq.c:292 > > invoke_softirq kernel/softirq.c:373 [inline] > > irq_exit+0x192/0x1d0 kernel/softirq.c:413 > > exiting_irq arch/x86/include/asm/apic.h:546 [inline] > > smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1146 > > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 > > </IRQ> > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20200331095737.GO20730%40hirez.programming.kicks-ass.net. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
