INFO: task hung in switchdev_deferred_process_work (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d15be546 Merge tag 'media/v5.8-3' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16ea7c64900000
kernel config: https://syzkaller.appspot.com/x/.config?x=f87a5e4232fdb267
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecc009e206a956ab317
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ecc00...@syzkaller.appspotmail.com

INFO: task kworker/1:8:3807 blocked for more than 143 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:8 D24832 3807 2 0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
INFO: task kworker/1:0:20078 blocked for more than 143 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0 D25504 20078 2 0x00004000
Workqueue: events linkwatch_event
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
linkwatch_event+0xb/0x60 net/core/link_watch.c:250
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
INFO: task syz-executor.1:30871 blocked for more than 144 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D28664 30871 6970 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fdf54395c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000380 RDI: 0000000000000006
RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffc325652af R14: 00007fdf543969c0 R15: 000000000078bfac
INFO: task syz-executor.1:30878 blocked for more than 144 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29832 30878 6970 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1061
sock_ioctl+0x3b8/0x730 net/socket.c:1199
vfs_ioctl fs/ioctl.c:48 [inline]
ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
__do_sys_ioctl fs/ioctl.c:762 [inline]
__se_sys_ioctl fs/ioctl.c:760 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fdf54374c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000011d80 RCX: 000000000045c1f9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000005
RBP: 000000000078c080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c
R13: 00007ffc325652af R14: 00007fdf543759c0 R15: 000000000078c04c
INFO: task syz-executor.1:30889 blocked for more than 145 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D28664 30889 6970 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fdf54353c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000380 RDI: 0000000000000006
RBP: 000000000078c120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0ec
R13: 00007ffc325652af R14: 00007fdf543549c0 R15: 000000000078c0ec
INFO: task syz-executor.1:30890 blocked for more than 145 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D28664 30890 6970 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fdf54332c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000007
RBP: 000000000078c1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c18c
R13: 00007ffc325652af R14: 00007fdf543339c0 R15: 000000000078c18c
INFO: task syz-executor.2:30867 blocked for more than 146 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D28664 30867 7073 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fb6eef7cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000006
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffec53b2bcf R14: 00007fb6eef7d9c0 R15: 000000000078bf0c
INFO: task syz-executor.2:30872 blocked for more than 146 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D27984 30872 7073 0x00004004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fb6eef5bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffec53b2bcf R14: 00007fb6eef5c9c0 R15: 000000000078bfac
INFO: task syz-executor.2:30877 blocked for more than 146 seconds.
Not tainted 5.8.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D28664 30877 7073 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3458 [inline]
__schedule+0x91f/0x2250 kernel/sched/core.c:4215
schedule+0xd0/0x2a0 kernel/sched/core.c:4290
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4349
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007fb6eef3ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000078c080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c
R13: 00007ffec53b2bcf R14: 00007fb6eef3b9c0 R15: 000000000078c04c

Showing all locks held in the system:
2 locks held by kworker/u4:0/7:
#0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1261 [inline]
#0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x25b/0x2250 kernel/sched/core.c:4140
#1: ffff8880ae620f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:817
1 lock held by khungtaskd/1153:
#0: ffffffff89bc11c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779
3 locks held by kworker/1:8/3807:
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
#1: ffffc90004bb7da8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
#2: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
1 lock held by in:imklog/6504:
#0: ffff8880a71efdb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
3 locks held by kworker/0:4/7824:
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888214f4fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
#1: ffffc9001627fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
#2: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4543
3 locks held by kworker/1:0/20078:
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
#1: ffffc9000816fda8 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
#2: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:250
2 locks held by syz-executor.1/30864:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
#1: ffffffff89bc5820 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff89bc5820 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4e8/0x5f0 kernel/rcu/tree_exp.h:838
1 lock held by syz-executor.1/30871:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
1 lock held by syz-executor.1/30878:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1061
1 lock held by syz-executor.1/30889:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
1 lock held by syz-executor.1/30890:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
1 lock held by syz-executor.2/30867:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
1 lock held by syz-executor.2/30872:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457
1 lock held by syz-executor.2/30877:
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a7b8b28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1153 Comm: khungtaskd Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x18f/0x20d lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b3/0x223 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+0xd7d/0x1000 kernel/hung_task.c:295
kthread+0x3b5/0x4a0 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:batadv_nc_purge_paths+0x9d/0x3a0 net/batman-adv/network-coding.c:437
Code: c7 44 24 0c 00 00 00 00 4c 01 f0 85 db 48 89 4c 24 28 48 89 44 24 30 0f 84 50 02 00 00 e8 ab 0a a9 f9 48 8b 44 24 30 80 38 00 <0f> 85 9e 02 00 00 48 8b 04 24 8b 5c 24 0c 48 8b 00 48 8d 2c d8 48
RSP: 0018:ffffc90000cdfc10 EFLAGS: 00000246
RAX: ffffed10143b1ec8 RBX: 0000000000000080 RCX: ffffffff87cab428
RDX: ffff8880a95e81c0 RSI: ffffffff87cab1e5 RDI: 0000000000000004
RBP: 0000000000000061 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000080 R11: 0000000000000000 R12: ffff888055ae96f0
R13: ffff888055ae8bc0 R14: dffffc0000000000 R15: ffffffff87cab790
FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4220ef500 CR3: 000000003a567000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
batadv_nc_worker+0x868/0xe50 net/batman-adv/network-coding.c:721
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 5695e516 Merge tag 'io_uring-worker.v3-2021-02-25' of git:..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=135da5cad00000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c76dad0946df1f3
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecc009e206a956ab317
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15aaeff2d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fbcb6cd00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ecc00...@syzkaller.appspotmail.com

INFO: task kworker/1:0:8387 blocked for more than 143 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:0 state:D stack:25896 pid: 8387 ppid: 2 flags:0x00004000

Workqueue: events switchdev_deferred_process_work
Call Trace:

context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
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
INFO: task kworker/1:6:9697 blocked for more than 143 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:6 state:D stack:25688 pid: 9697 ppid: 2 flags:0x00004000
Workqueue: events rfkill_global_led_trigger_worker
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
rfkill_global_led_trigger_worker+0x17/0x110 net/rfkill/core.c:180
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
INFO: task syz-executor417:12942 blocked for more than 143 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor417 state:D stack:23856 pid:12942 ppid: 12792 flags:0x00000000
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
sock_sendmsg_nosec net/socket.c:654 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:674
__sys_sendto+0x21c/0x320 net/socket.c:1977
__do_sys_sendto net/socket.c:1989 [inline]
__se_sys_sendto net/socket.c:1985 [inline]
__x64_sys_sendto+0xdd/0x1b0 net/socket.c:1985
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x40c6dc
RSP: 002b:00000000005ffdf0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000601080 RCX: 000000000040c6dc
RDX: 0000000000000020 RSI: 00000000006010d0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00000000005ffe44 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000005fff10
R13: 00000000006010d0 R14: 0000000000000004 R15: 0000000000000000
INFO: task kworker/0:28:21057 blocked for more than 144 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/0:28 state:D stack:27096 pid:21057 ppid: 2 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
addrconf_dad_work+0xa3/0x12b0 net/ipv6/addrconf.c:4031
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
INFO: task kworker/1:14:21066 blocked for more than 144 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:14 state:D stack:27392 pid:21066 ppid: 2 flags:0x00004000

Workqueue: events linkwatch_event
Call Trace:

context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
linkwatch_event+0xb/0x60 net/core/link_watch.c:250
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
INFO: task syz-executor417:21726 blocked for more than 144 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor417 state:D stack:28528 pid:21726 ppid: 8422 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
cfg80211_rfkill_set_block net/wireless/core.c:304 [inline]
cfg80211_rfkill_set_block+0x23/0x40 net/wireless/core.c:297
rfkill_set_block+0x1f9/0x540 net/rfkill/core.c:343
rfkill_fop_write+0x267/0x500 net/rfkill/core.c:1267
vfs_write+0x28e/0xa30 fs/read_write.c:603
ksys_write+0x1ee/0x250 fs/read_write.c:658
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x453a49
RSP: 002b:00007ff5d8620208 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004f0028 RCX: 0000000000453a49
RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000004f0020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004f002c
R13: 00000000005ffbcf R14: 00007ff5d8620300 R15: 0000000000022000
INFO: task syz-executor417:21727 blocked for more than 144 seconds.
Not tainted 5.11.0-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor417 state:D stack:28528 pid:21727 ppid: 8422 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213
__mutex_lock_common kernel/locking/mutex.c:1023 [inline]
__mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093
rfkill_fop_open+0xfe/0x700 net/rfkill/core.c:1147
misc_open+0x372/0x4a0 drivers/char/misc.c:141
chrdev_open+0x266/0x770 fs/char_dev.c:414
do_dentry_open+0x4b9/0x11b0 fs/open.c:826
do_open fs/namei.c:3365 [inline]
path_openat+0x1c0e/0x27e0 fs/namei.c:3498
do_filp_open+0x17e/0x3c0 fs/namei.c:3525
do_sys_openat2+0x16d/0x420 fs/open.c:1187
do_sys_open fs/open.c:1203 [inline]
__do_sys_openat fs/open.c:1219 [inline]
__se_sys_openat fs/open.c:1214 [inline]
__x64_sys_openat+0x13f/0x1f0 fs/open.c:1214
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x453a49
RSP: 002b:00007ff5d85ff208 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f0038 RCX: 0000000000453a49
RDX: 0000000000000001 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 00000000004f0030 R08: 00007ff5d85ff700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004f003c
R13: 00000000005ffbcf R14: 00007ff5d85ff300 R15: 0000000000022000

Showing all locks held in the system:

5 locks held by kworker/u4:5/826:
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc900032dfda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffffff8d669490 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557
#3: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11378 [inline]
#3: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe8/0x3c0 net/core/dev.c:11416
#4: ffffffff8bf7cd28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#4: ffffffff8bf7cd28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836
1 lock held by khungtaskd/1664:
#0: ffffffff8bf74160 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6327
1 lock held by in:imklog/8074:
#0: ffff88801c2520f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:961
3 locks held by kworker/1:0/8387:
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc9000172fda8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
3 locks held by kworker/1:6/9697:
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc9000a9c7da8 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffffff8da55548 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_global_led_trigger_worker+0x17/0x110 net/rfkill/core.c:180
1 lock held by syz-executor417/12942:
#0: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550
2 locks held by kworker/u4:8/20993:
2 locks held by kworker/0:27/21056:
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888010866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc9000b457da8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
3 locks held by kworker/0:28/21057:
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888021399d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc9000b467da8 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xa3/0x12b0 net/ipv6/addrconf.c:4031
3 locks held by kworker/1:14/21066:
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc9000b4f7da8 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:250
2 locks held by syz-executor417/21726:
#0: ffffffff8da55548 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x500 net/rfkill/core.c:1259
#1: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_rfkill_set_block net/wireless/core.c:304 [inline]
#1: ffffffff8d67cbe8 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_rfkill_set_block+0x23/0x40 net/wireless/core.c:297
2 locks held by syz-executor417/21727:
#0: ffffffff8c964868 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x55/0x4a0 drivers/char/misc.c:107
#1: ffffffff8da55548 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_open+0xfe/0x700 net/rfkill/core.c:1147

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1664 Comm: khungtaskd Not tainted 5.11.0-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+0xfa/0x151 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:209 [inline]

watchdog+0xd48/0xfb0 kernel/hung_task.c:294
kthread+0x3b1/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:

NMI backtrace for cpu 1

CPU: 1 PID: 20993 Comm: kworker/u4:8 Not tainted 5.11.0-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_acquire+0x3c/0x54c0 kernel/locking/lockdep.c:4758
Code: 89 f5 53 48 81 ec e8 00 00 00 48 8b 84 24 20 01 00 00 48 c7 84 24 88 00 00 00 b3 8a b5 41 48 c7 84 24 90 00 00 00 05 be eb 8a <48> c7 84 24 98 00 00 00 e0 c9 58 81 44 89 44 24 08 48 89 44 24 20
RSP: 0018:ffffc9000b2d7a60 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 1ffff9200165af76 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8bf74160
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff1b8c4f1 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8bf74160 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f56f8869000 CR3: 000000001c7ee000 CR4: 00000000001506e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475
rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
rcu_read_lock include/linux/rcupdate.h:656 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline]
batadv_nc_worker+0x12d/0xe50 net/batman-adv/network-coding.c:715
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

[Hillf Danton]

On 27 Feb 2021 17:09:15 -0800

> HEAD commit: 5695e516 Merge tag 'io_uring-worker.v3-2021-02-25' of git:..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fbcb6cd00000

See if batman is a rcu hog.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

--- x/net/batman-adv/network-coding.c
+++ y/net/batman-adv/network-coding.c
@@ -713,6 +713,7 @@ static void batadv_nc_worker(struct work
unsigned long timeout;

delayed_work = to_delayed_work(work);
+ return;
priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
bat_priv = container_of(priv_nc, struct batadv_priv, nc);

--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
SYZFAIL: wrong response packet

2023/03/25 01:23:02 result: hanged=false err=executor 1: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)


2023/03/25 01:23:02 result: hanged=false err=executor 2: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)


2023/03/25 01:23:05 result: hanged=false err=executor 1: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)


2023/03/25 01:23:05 executed programs: 8
2023/03/25 01:23:07 result: hanged=false err=executor 4: exit status 67
SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67


SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67
2023/03/25 01:23:07 result: hanged=false err=executor 3: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67
2023/03/25 01:23:07 result: hanged=false err=executor 5: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67
2023/03/25 01:23:10 result: hanged=false err=executor 4: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)


2023/03/25 01:23:11 result: hanged=false err=executor 2: exit status 67
SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67


SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67
2023/03/25 01:23:11 executed programs: 21
2023/03/25 01:23:11 result: hanged=false err=executor 5: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)


2023/03/25 01:23:11 result: hanged=false err=executor 3: EOF
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)




Tested on:

commit: e76db6e5 Merge tag 'arm-fixes-6.3-2' of git://git.kern..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=13ac8d0ec80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a2ca2de6ed94982
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecc009e206a956ab317
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=1169ef75c80000

[Hillf Danton]

On 27 Feb 2021 17:09:15 -0800

> HEAD commit: 5695e516 Merge tag 'io_uring-worker.v3-2021-02-25' of git:..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fbcb6cd00000

See if batman has a rcu hog.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

--- x/net/batman-adv/network-coding.c
+++ y/net/batman-adv/network-coding.c

@@ -715,6 +715,7 @@ static void batadv_nc_worker(struct work
delayed_work = to_delayed_work(work);

priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
bat_priv = container_of(priv_nc, struct batadv_priv, nc);

+ goto out;

batadv_nc_purge_orig_hash(bat_priv);
batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
@@ -737,6 +738,7 @@ static void batadv_nc_worker(struct work
bat_priv->nc.timestamp_sniffed_purge = jiffies;
}

+out:
/* Schedule a new check */
batadv_nc_start_timer(bat_priv);
}
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:

SYZFAIL: initialize_wifi_devices: failed set up IBSS network

2023/03/25 01:50:35 result: hanged=false err=executor 0: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 01:50:35 result: hanged=false err=executor 1: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network

device=1 (errno 132: Operation not possible due to RF-kill)

loop exited with status 67

2023/03/25 01:50:35 result: hanged=false err=executor 5: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 01:50:35 result: hanged=false err=executor 4: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 01:50:38 result: hanged=false err=executor 0: EOF

SYZFAIL: wrong response packet
(errno 16: Device or resource busy)

2023/03/25 01:50:39 result: hanged=false err=executor 5: EOF

SYZFAIL: wrong response packet
(errno 16: Device or resource busy)

2023/03/25 01:50:39 executed programs: 29
2023/03/25 01:50:44 executed programs: 34


Tested on:

commit: 65aca32e Merge tag 'mm-hotfixes-stable-2023-03-24-17-0..

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

console output: https://syzkaller.appspot.com/x/log.txt?x=12e930b6c80000

kernel config: https://syzkaller.appspot.com/x/.config?x=4a2ca2de6ed94982
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecc009e206a956ab317
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=16379cfec80000

[Hillf Danton]

On 27 Feb 2021 17:09:15 -0800

> HEAD commit: 5695e516 Merge tag 'io_uring-worker.v3-2021-02-25' of git:..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fbcb6cd00000

See if it can be reproduced.

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
SYZFAIL: initialize_wifi_devices: failed set up IBSS network

2023/03/25 02:28:33 executed programs: 6
2023/03/25 02:28:33 result: hanged=false err=executor 0: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 02:28:34 result: hanged=false err=executor 1: exit status 67

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67


SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 02:28:34 result: hanged=false err=executor 2: failed to write control pipe: write |1: broken pipe

SYZFAIL: initialize_wifi_devices: failed set up IBSS network
device=0 (errno 132: Operation not possible due to RF-kill)
loop exited with status 67

2023/03/25 02:28:38 result: hanged=false err=executor 1: EOF

SYZFAIL: wrong response packet
(errno 16: Device or resource busy)

2023/03/25 02:28:38 result: hanged=false err=executor 0: EOF

SYZFAIL: wrong response packet
(errno 16: Device or resource busy)

2023/03/25 02:28:38 executed programs: 27

Tested on:

commit: 65aca32e Merge tag 'mm-hotfixes-stable-2023-03-24-17-0..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

console output: https://syzkaller.appspot.com/x/log.txt?x=13227efec80000

kernel config: https://syzkaller.appspot.com/x/.config?x=4a2ca2de6ed94982
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecc009e206a956ab317
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.