INFO: task can't die in __local_bh_enable_ip

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d1d2220c Add linux-next specific files for 20200924
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1387e29d900000
kernel config: https://syzkaller.appspot.com/x/.config?x=254e028a642027c
dashboard link: https://syzkaller.appspot.com/bug?extid=ea17a53bf44cc0e06331
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [da...@davemloft.net ku...@kernel.org linux-...@vger.kernel.org mathew.j....@linux.intel.com matthie...@tessares.net mp...@lists.01.org net...@vger.kernel.org]

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+ea17a5...@syzkaller.appspotmail.com

INFO: task syz-executor.4:8800 can't die for more than 143 seconds.
task:syz-executor.4 state:R running task stack:26544 pid: 8800 ppid: 6889 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:3777 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4526
preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:4685
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:40
__local_bh_enable_ip+0x1a0/0x1f0 kernel/softirq.c:202
__mptcp_move_skbs+0x216/0x510 net/mptcp/protocol.c:1466
mptcp_recvmsg+0x1015/0x1880 net/mptcp/protocol.c:1507
inet6_recvmsg+0x11b/0x5d0 net/ipv6/af_inet6.c:654
sock_recvmsg_nosec net/socket.c:885 [inline]
sock_recvmsg net/socket.c:903 [inline]
sock_recvmsg net/socket.c:899 [inline]
____sys_recvmsg+0x2c4/0x640 net/socket.c:2585
___sys_recvmsg+0x127/0x200 net/socket.c:2627
do_recvmmsg+0x252/0x700 net/socket.c:2727
__sys_recvmmsg net/socket.c:2806 [inline]
__do_sys_recvmmsg net/socket.c:2829 [inline]
__se_sys_recvmmsg net/socket.c:2822 [inline]
__x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2822
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: Bad RIP value.
RSP: 002b:00007f190ef2bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 0000000000027000 RCX: 000000000045e179
RDX: 0000000000000002 RSI: 0000000020004280 RDI: 0000000000000003
RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffeffe732af R14: 00007f190ef2c9c0 R15: 000000000118cf4c

Showing all locks held in the system:
1 lock held by khungtaskd/1183:
#0: ffffffff8a553d40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6221
1 lock held by in:imklog/6767:
#0: ffff8880992e5370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor.4/8800:

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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.