Hello, syzbot found the following issue on: HEAD commit: d5ae8d7f85b7 Revert "media: dvb header files: move some he.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=155fa21e300000 kernel config: https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56 dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927 compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a1ab0e300000 Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15662ee1300000 final oops: https://syzkaller.appspot.com/x/report.txt?x=17662ee1300000 console output: https://syzkaller.appspot.com/x/log.txt?x=13662ee1300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ada0f7d3d9fd2016d927@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor.0:8700 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5938 schedule+0x14b/0x210 kernel/sched/core.c:6017 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857 do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157 usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63 do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236 proc_bulk drivers/usb/core/devio.c:1273 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline] usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 RSP: 002b:00007f15a90dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000020000340 RSI: 00000000c0185502 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcc552e1bf R14: 00007f15a90dc300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1610: #0: ffffffff8c717ec0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151 1 lock held by in:imklog/8130: #0: ffff888035998870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1610 Comm: khungtaskd Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1d3/0x29f lib/dump_stack.c:105 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xd06/0xd50 kernel/hung_task.c:295 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_is_held_type+0x1/0x180 kernel/locking/lockdep.c:5653 Code: 74 df 83 3d d8 22 e1 03 00 75 d6 48 c7 c7 80 c3 2e 8a 48 c7 c6 c0 c3 2e 8a 31 c0 e8 c9 8d 72 f7 0f 0b eb bd e8 90 fd ff ff 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 RSP: 0018:ffffc90000cf7990 EFLAGS: 00000202 RAX: 1ffffffff18e3801 RBX: 1ffff9200019ef34 RCX: 0000000080000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c717e20 RBP: ffffc90000cf7a28 R08: dffffc0000000000 R09: fffffbfff1b74ee6 R10: fffffbfff1b74ee6 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff9200019ef58 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a1e997000 CR3: 000000000c48e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125 trace_lock_acquire+0x59/0x190 include/trace/events/lock.h:13 lock_acquire+0xa4/0x4a0 kernel/locking/lockdep.c:5596 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline] batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:715 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 74 df je 0xffffffe1 2: 83 3d d8 22 e1 03 00 cmpl $0x0,0x3e122d8(%rip) # 0x3e122e1 9: 75 d6 jne 0xffffffe1 b: 48 c7 c7 80 c3 2e 8a mov $0xffffffff8a2ec380,%rdi 12: 48 c7 c6 c0 c3 2e 8a mov $0xffffffff8a2ec3c0,%rsi 19: 31 c0 xor %eax,%eax 1b: e8 c9 8d 72 f7 callq 0xf7728de9 20: 0f 0b ud2 22: eb bd jmp 0xffffffe1 24: e8 90 fd ff ff callq 0xfffffdb9 29: 55 push %rbp * 2a: 41 57 push %r15 <-- trapping instruction 2c: 41 56 push %r14 2e: 41 55 push %r13 30: 41 54 push %r12 32: 53 push %rbx 33: 48 83 ec 10 sub $0x10,%rsp 37: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 3e: 00 00 --- 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
