Hello, syzbot found the following issue on: HEAD commit: c9194f32bfd9 Merge tag 'ext4_for_linus_stable' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1488f59e300000 kernel config: https://syzkaller.appspot.com/x/.config?x=343fd21f6f4da2d6 dashboard link: https://syzkaller.appspot.com/bug?extid=be2baed593ea56c6a84c compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b5afc6300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15fcd192300000 Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17dce4fa300000 final oops: https://syzkaller.appspot.com/x/report.txt?x=143ce4fa300000 console output: https://syzkaller.appspot.com/x/log.txt?x=103ce4fa300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+be2baed593ea56c6a84c@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor446:8489 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor446 state:D stack:28712 pid: 8489 ppid: 8452 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hci_req_sync+0x33/0xd0 net/bluetooth/hci_request.c:276 hci_inquiry+0x6f4/0x9e0 net/bluetooth/hci_core.c:1357 hci_sock_ioctl+0x1a7/0x910 net/bluetooth/hci_sock.c:1060 sock_do_ioctl+0xcb/0x2d0 net/socket.c:1094 sock_ioctl+0x477/0x6a0 net/socket.c:1221 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x446449 RSP: 002b:00007f36ab8342e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004cb400 RCX: 0000000000446449 RDX: 00000000200000c0 RSI: 00000000800448f0 RDI: 0000000000000004 RBP: 00000000004cb40c R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000004 R14: 00007f36ab8346b8 R15: 00000000004cb408 INFO: task syz-executor446:8491 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor446 state:D stack:28176 pid: 8491 ppid: 8452 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hci_req_sync+0x33/0xd0 net/bluetooth/hci_request.c:276 hci_inquiry+0x6f4/0x9e0 net/bluetooth/hci_core.c:1357 hci_sock_ioctl+0x1a7/0x910 net/bluetooth/hci_sock.c:1060 sock_do_ioctl+0xcb/0x2d0 net/socket.c:1094 sock_ioctl+0x477/0x6a0 net/socket.c:1221 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x446449 RSP: 002b:00007f36ab8342e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004cb400 RCX: 0000000000446449 RDX: 00000000200000c0 RSI: 00000000800448f0 RDI: 0000000000000004 RBP: 00000000004cb40c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000004 R14: 00007f36ab8346b8 R15: 00000000004cb408 Showing all locks held in the system: 6 locks held by kworker/u4:0/8: 1 lock held by khungtaskd/1635: #0: ffffffff8b97c180 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/8352: #0: ffff888033e1d4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 1 lock held by syz-executor446/8486: #0: ffff8880349c4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_req_sync+0x33/0xd0 net/bluetooth/hci_request.c:276 1 lock held by syz-executor446/8489: #0: ffff8880349c4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_req_sync+0x33/0xd0 net/bluetooth/hci_request.c:276 1 lock held by syz-executor446/8491: #0: ffff8880349c4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_req_sync+0x33/0xd0 net/bluetooth/hci_request.c:276 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1635 Comm: khungtaskd Not tainted 5.14.0-rc4-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+0xcd/0x134 lib/dump_stack.c:105 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:210 [inline] watchdog+0xd0a/0xfc0 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 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: 8 Comm: kworker/u4:0 Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:967 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 d0 47 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90000cd7a00 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d570c0 RCX: 0000000000000000 RDX: ffff88813fe6d4c0 RSI: ffffffff816a6400 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816a6426 R11: 0000000000000000 R12: ffffed10173aae19 R13: 0000000000000001 R14: ffff8880b9d570c8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f56e8f43000 CR3: 000000000b68e000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1133 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x47d/0x560 arch/x86/kernel/alternative.c:1183 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 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:623 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:615 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 --- 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
