On 4/19/21 10:10 PM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 1216f02e Add linux-next specific files for 20210415 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=130bbeded00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3491b04113499f81 > dashboard link: https://syzkaller.appspot.com/bug?extid=47fc00967b06a3019bd2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14734dc5d00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16dfaf65d00000 The repro looks pretty much like sqpoll-exit-hang test and issues that were just recently fixed. #syz test: git://git.kernel.dk/linux-block for-5.13/io_uring > > The issue was bisected to: > > commit d9d05217cb6990b9a56e13b56e7a1b71e2551f6c > Author: Pavel Begunkov <asml.silence@xxxxxxxxx> > Date: Fri Jan 8 20:57:25 2021 +0000 > > io_uring: stop SQPOLL submit on creator's death > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11b86f9ad00000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=13b86f9ad00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=15b86f9ad00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+47fc00967b06a3019bd2@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death") > > INFO: task iou-sqp-8700:8701 blocked for more than 143 seconds. > Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:iou-sqp-8700 state:D stack:28960 pid: 8701 ppid: 8414 flags:0x00004004 > Call Trace: > context_switch kernel/sched/core.c:4329 [inline] > __schedule+0x917/0x2170 kernel/sched/core.c:5079 > schedule+0xcf/0x270 kernel/sched/core.c:5158 > __io_uring_cancel+0x285/0x420 fs/io_uring.c:8977 > io_uring_files_cancel include/linux/io_uring.h:16 [inline] > do_exit+0x299/0x2a70 kernel/exit.c:780 > io_sq_thread+0x60a/0x1340 fs/io_uring.c:6873 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > Showing all locks held in the system: > 1 lock held by khungtaskd/1653: > #0: ffffffff8bf76560 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 > 1 lock held by in:imklog/8133: > #0: ffff888013088370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 > > ============================================= > > NMI backtrace for cpu 1 > CPU: 1 PID: 1653 Comm: khungtaskd Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 > nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] > watchdog+0xd3b/0xf50 kernel/hung_task.c:338 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > Sending NMI from CPU 1 to CPUs 0: > NMI backtrace for cpu 0 > CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: events toggle_allocation_gate > RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:85 [inline] > RIP: 0010:preempt_count_sub+0x56/0x150 kernel/sched/core.c:4772 > Code: 85 e4 00 00 00 8b 0d 19 08 e5 0e 85 c9 75 1b 65 8b 05 ae 60 b3 7e 89 c2 81 e2 ff ff ff 7f 39 da 7c 13 81 fb fe 00 00 00 76 63 <f7> db 65 01 1d 91 60 b3 7e 5b c3 e8 4a cd c2 07 85 c0 74 f5 48 c7 > RSP: 0018:ffffc90000cc79f8 EFLAGS: 00000002 > RAX: 0000000080000002 RBX: 0000000000000001 RCX: 0000000000000000 > RDX: 0000000000000002 RSI: ffffffff83e7543f RDI: 0000000000000001 > RBP: ffff8880b9c34a80 R08: 0000000000000002 R09: 000000000000eb19 > R10: ffffffff83e7538c R11: 000000000000003f R12: 0000000000000008 > R13: ffff888140120660 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffa2b511018 CR3: 000000000bc8e000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > flush_tlb_mm_range+0x111/0x230 arch/x86/mm/tlb.c:957 > __text_poke+0x590/0x8c0 arch/x86/kernel/alternative.c:837 > text_poke_bp_batch+0x3d7/0x560 arch/x86/kernel/alternative.c:1150 > text_poke_flush arch/x86/kernel/alternative.c:1240 [inline] > text_poke_flush arch/x86/kernel/alternative.c:1237 [inline] > text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1247 > arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:122 > jump_label_update+0x1da/0x400 kernel/jump_label.c:825 > static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 > static_key_enable+0x16/0x20 kernel/jump_label.c:190 > toggle_allocation_gate mm/kfence/core.c:610 [inline] > toggle_allocation_gate+0xbf/0x2e0 mm/kfence/core.c:602 > process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 > worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > > --- > This report 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 syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches > -- Pavel Begunkov
