BUG: workqueue lockup

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4e76528b Merge 4.14.81 into android-4.14
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=15d96a47400000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e4a95e0186919ba
dashboard link: https://syzkaller.appspot.com/bug?extid=d06b99ae806747aaba18
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1411f225400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=156be015400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d06b99...@syzkaller.appspotmail.com

random: sshd: uninitialized urandom read (32 bytes read)
audit: type=1400 audit(1542701193.726:7): avc: denied { map } for
pid=1897 comm="syz-executor900" path="/root/syz-executor900093753"
dev="sda1" ino=16461 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 280s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256
in-flight: 22:rtc_timer_do_work
pending: vmstat_shepherd
workqueue events_power_efficient: flags=0x80
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
pending: neigh_periodic_work
workqueue mm_percpu_wq: flags=0x8
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
pending: vmstat_update
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=281s workers=2 idle: 3


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[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: d0545055 ANDROID: build: cuttlefish: Upgrade clang to newe..
git tree: android-4.9
console output: https://syzkaller.appspot.com/x/log.txt?x=1619f827800000
kernel config: https://syzkaller.appspot.com/x/.config?x=e4b307d57c80b074
dashboard link: https://syzkaller.appspot.com/bug?extid=79938bdf36ff188fb61d

compiler: gcc (GCC) 8.0.1 20180413 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a95737800000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10da944f800000

IMPORTANT: if you fix the bug, please add the following tag to the commit:

Reported-by: syzbot+79938b...@syzkaller.appspotmail.com

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)

IPVS: Creating netns size=2536 id=1
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 41s!

Showing busy workqueues and worker pools:
workqueue events: flags=0x0

pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
pending: defense_work_handler
workqueue kblockd: flags=0x18
pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=1/256
pending: blk_mq_requeue_work
workqueue vmstat: flags=0xc

pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
pending: vmstat_update

workqueue dm_bufio_cache: flags=0x8

pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256

pending: work_fn