On Sat, Jan 19, 2019 at 1:39 PM syzbot <syzbot+3d95205bfac60602a...@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 9673b4aa71ca Add linux-next specific files for 20190118 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=10c2097f400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4086e03c3128165 > dashboard link: https://syzkaller.appspot.com/bug?extid=3d95205bfac60602a727 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a02f6f400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16c4dc28c00000
+Ingo, Peter Looks like another problem with scheduler as the repro uses perf_event_open and sched_setattr. > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+3d95205bfac60602a...@syzkaller.appspotmail.com > > hrtimer: interrupt took 39380 ns > rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > rcu: (detected by 0, t=10502 jiffies, g=5593, q=4) > rcu: All QSes seen, last rcu_preempt kthread activity 10503 > (4295058157-4295047654), jiffies_till_next_fqs=1, root ->qsmask 0x0 > syz-executor570 R running task 23848 7948 7931 0x00000000 > Call Trace: > <IRQ> > sched_show_task kernel/sched/core.c:5296 [inline] > sched_show_task.cold+0x271/0x2d3 kernel/sched/core.c:5271 > print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1324 > check_cpu_stall kernel/rcu/tree.c:1452 [inline] > rcu_pending kernel/rcu/tree.c:3114 [inline] > rcu_sched_clock_irq+0xf36/0x1380 kernel/rcu/tree.c:2555 > update_process_times+0x32/0x80 kernel/time/timer.c:1635 > tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 > tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 > __run_hrtimer kernel/time/hrtimer.c:1389 [inline] > __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 > hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] > smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 > </IRQ> > RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101 > Code: 46 df ff ff 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b > 15 a8 b4 7f 7e 81 e2 00 01 1f 00 75 2b 8b 90 e0 12 00 00 <83> fa 02 75 20 > 48 8b 88 e8 12 00 00 8b 80 e4 12 00 00 48 8b 11 48 > RSP: 0018:ffff88808d0bf460 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 > RAX: ffff888092ba00c0 RBX: ffff888097e1bc80 RCX: ffffffff835a5f5c > RDX: 0000000000000000 RSI: ffffffff835a5bf6 RDI: 0000000000000005 > RBP: ffff88808d0bf460 R08: ffff888092ba00c0 R09: ffffed1015cc5b90 > R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: ffff88821bc94bb0 > R13: ffff88821bc94bb0 R14: ffff8880a3586958 R15: ffff88808d0bf5f0 > aa_file_perm+0x226/0x1180 security/apparmor/file.c:615 > common_file_perm+0x1cb/0x820 security/apparmor/lsm.c:459 > apparmor_file_permission+0x25/0x30 security/apparmor/lsm.c:472 > security_file_permission+0x7e/0x320 security/security.c:1326 > rw_verify_area+0x110/0x360 fs/read_write.c:391 > do_iter_write+0x100/0x610 fs/read_write.c:951 > vfs_iter_write+0x77/0xb0 fs/read_write.c:969 > iter_file_splice_write+0x885/0xfc0 fs/splice.c:749 > do_splice_from fs/splice.c:851 [inline] > direct_splice_actor+0x126/0x1a0 fs/splice.c:1023 > splice_direct_to_actor+0x3be/0x9d0 fs/splice.c:978 > do_splice_direct+0x2c7/0x420 fs/splice.c:1066 > do_sendfile+0x61a/0xe60 fs/read_write.c:1436 > __do_sys_sendfile64 fs/read_write.c:1491 [inline] > __se_sys_sendfile64 fs/read_write.c:1483 [inline] > __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483 > do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x446a19 > Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fc79f06bda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028 > RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a19 > RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003 > RBP: 00000000006dcc30 R08: 0000000000000000 R09: 0000000000000000 > R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc3c > R13: 00008080fffffffe R14: 00007fc79f06c9c0 R15: 00000000006dcd2c > rcu: rcu_preempt kthread starved for 10583 jiffies! g5593 f0x2 > RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 > rcu: RCU grace-period kthread stack dump: > rcu_preempt R running task 25832 10 2 0x80000000 > Call Trace: > context_switch kernel/sched/core.c:2834 [inline] > __schedule+0x897/0x1e60 kernel/sched/core.c:3475 > schedule+0xfe/0x350 kernel/sched/core.c:3519 > schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803 > rcu_gp_fqs_loop+0x6d4/0x980 kernel/rcu/tree.c:1982 > rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2139 > kthread+0x357/0x430 kernel/kthread.c:247 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 > sched: RT throttling activated > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > 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+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009ef2bf057fcee913%40google.com. > For more options, visit https://groups.google.com/d/optout.