Hello, syzbot found the following issue on: HEAD commit: 3dbdb38e Merge branch 'for-5.14' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16a845d8300000 kernel config: https://syzkaller.appspot.com/x/.config?x=1700b0b2b41cd52c dashboard link: https://syzkaller.appspot.com/bug?extid=0fe7752e52337864d29b compiler: Debian clang version 11.0.1-2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=156d30d2300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13bc89c4300000 The issue was bisected to: commit c76f48eb5c084b1e15c931ae8cc1826cd771d70d Author: Christoph Hellwig <hch@xxxxxx> Date: Tue Apr 6 06:22:56 2021 +0000 block: take bd_mutex around delete_partitions in del_gendisk bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1630eac4300000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1530eac4300000 console output: https://syzkaller.appspot.com/x/log.txt?x=1130eac4300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0fe7752e52337864d29b@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: c76f48eb5c08 ("block: take bd_mutex around delete_partitions in del_gendisk") INFO: task systemd-udevd:8423 blocked for more than 143 seconds. Tainted: G W 5.13.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-udevd state:D stack:25776 pid: 8423 ppid: 4859 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5940 schedule+0x14b/0x210 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 del_gendisk+0x86/0x610 block/genhd.c:587 nbd_dev_remove drivers/block/nbd.c:224 [inline] nbd_put+0x8d/0x170 drivers/block/nbd.c:246 blkdev_put_whole fs/block_dev.c:1277 [inline] blkdev_put+0x470/0x810 fs/block_dev.c:1574 blkdev_close+0x7a/0xa0 fs/block_dev.c:1584 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbc7200f270 RSP: 002b:00007ffca87ce908 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fbc7200f270 RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007fbc72ec9710 R08: 000000000000004a R09: 0000000000000008 R10: 00005640bf30ff58 R11: 0000000000000246 R12: 0000000000000000 R13: 00005640bf324680 R14: 0000000000000003 R15: 000000000000000e INFO: task syz-executor861:8425 blocked for more than 143 seconds. Tainted: G W 5.13.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor861 state:D stack:27216 pid: 8425 ppid: 8420 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5940 schedule+0x14b/0x210 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 nbd_genl_connect+0x24f/0x1aa0 drivers/block/nbd.c:1801 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0xfb4/0x13c0 net/netlink/genetlink.c:800 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg net/socket.c:722 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2385 ___sys_sendmsg net/socket.c:2439 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2468 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: 0033:0x4414f9 RSP: 002b:00007fff264c11e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000000882dd RCX: 00000000004414f9 RDX: 0000000000000800 RSI: 0000000020000340 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fff264c11f0 R11: 0000000000000246 R12: 00007fff264c121c R13: 431bde82d7b634db R14: 00007fff264c1230 R15: 00000000004004a0 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 PID: 1641 Comm: khungtaskd Tainted: G W 5.13.0-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_lvl+0x1d3/0x29f lib/dump_stack.c:96 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:209 [inline] watchdog+0xd06/0xd50 kernel/hung_task.c:294 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: 8402 Comm: kworker/0:3 Tainted: G W 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient toggle_allocation_gate RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:54 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x4d/0x2f0 mm/kasan/generic.c:189 Code: 48 c1 eb 2f 81 fb fe ff 01 00 0f 86 7a 02 00 00 49 89 fc 49 c1 ec 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 04 4c 8d 54 37 ff <49> c1 ea 03 49 bd 01 00 00 00 00 fc ff df 4d 01 ea 4d 89 d6 4d 29 RSP: 0018:ffffc90001c9f788 EFLAGS: 00000806 RAX: ffff8880300f0001 RBX: 000000000001ffff RCX: ffffffff812de007 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8fa3b199 RBP: ffffc90001c9f990 R08: dffffc0000000000 R09: fffffbfff1f47633 R10: ffffffff8fa3b199 R11: 0000000000000000 R12: 1ffffffff1f47633 R13: dffffc0000000000 R14: ffffffff8fa3b199 R15: 00002aaaaaaabd81 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f42e3bca000 CR3: 00000001400d4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memcpy+0x25/0x60 mm/kasan/shadow.c:65 __text_poke+0x557/0x8c0 arch/x86/kernel/alternative.c:841 text_poke arch/x86/kernel/alternative.c:900 [inline] text_poke_bp_batch+0x6b0/0x940 arch/x86/kernel/alternative.c:1178 text_poke_flush arch/x86/kernel/alternative.c:1268 [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:145 static_key_enable_cpuslocked+0x12d/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate+0xbf/0x440 mm/kfence/core.c:623 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 --- 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
