INFO: task can't die in gfs2_gl_hash_clear

From: syzbot
Date: Fri Oct 23 2020 - 04:27:20 EST


Hello,

syzbot found the following issue on:

HEAD commit: 9695c4ff Add linux-next specific files for 20201023
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1337677f900000
kernel config: https://syzkaller.appspot.com/x/.config?x=e4274439d0e6cdfa
dashboard link: https://syzkaller.appspot.com/bug?extid=08b6bdbd4c6e64e520ff
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+08b6bdbd4c6e64e520ff@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: task syz-executor.4:10332 can't die for more than 143 seconds.
task:syz-executor.4 state:D stack:25896 pid:10332 ppid: 8512 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:3773 [inline]
__schedule+0x893/0x2130 kernel/sched/core.c:4522
schedule+0xcf/0x270 kernel/sched/core.c:4600
schedule_timeout+0x148/0x250 kernel/time/timer.c:1881
gfs2_gl_hash_clear+0x240/0x270 fs/gfs2/glock.c:1989
gfs2_fill_super+0x1e81/0x23f0 fs/gfs2/ops_fstype.c:1233
get_tree_bdev+0x421/0x740 fs/super.c:1344
gfs2_get_tree+0x4a/0x270 fs/gfs2/ops_fstype.c:1256
vfs_get_tree+0x89/0x2f0 fs/super.c:1549
do_new_mount fs/namespace.c:2896 [inline]
path_mount+0x12ae/0x1e70 fs/namespace.c:3227
do_mount fs/namespace.c:3240 [inline]
__do_sys_mount fs/namespace.c:3448 [inline]
__se_sys_mount fs/namespace.c:3425 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3425
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4608aa
Code: Unable to access opcode bytes at RIP 0x460880.
RSP: 002b:00007f9dd27eda88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9dd27edb20 RCX: 00000000004608aa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f9dd27edae0
RBP: 00007f9dd27edae0 R08: 00007f9dd27edb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20
INFO: task syz-executor.4:10332 blocked for more than 143 seconds.
Not tainted 5.9.0-next-20201023-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:25896 pid:10332 ppid: 8512 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:3773 [inline]
__schedule+0x893/0x2130 kernel/sched/core.c:4522
schedule+0xcf/0x270 kernel/sched/core.c:4600
schedule_timeout+0x148/0x250 kernel/time/timer.c:1881
gfs2_gl_hash_clear+0x240/0x270 fs/gfs2/glock.c:1989
gfs2_fill_super+0x1e81/0x23f0 fs/gfs2/ops_fstype.c:1233
get_tree_bdev+0x421/0x740 fs/super.c:1344
gfs2_get_tree+0x4a/0x270 fs/gfs2/ops_fstype.c:1256
vfs_get_tree+0x89/0x2f0 fs/super.c:1549
do_new_mount fs/namespace.c:2896 [inline]
path_mount+0x12ae/0x1e70 fs/namespace.c:3227
do_mount fs/namespace.c:3240 [inline]
__do_sys_mount fs/namespace.c:3448 [inline]
__se_sys_mount fs/namespace.c:3425 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3425
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4608aa
Code: Unable to access opcode bytes at RIP 0x460880.
RSP: 002b:00007f9dd27eda88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9dd27edb20 RCX: 00000000004608aa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f9dd27edae0
RBP: 00007f9dd27edae0 R08: 00007f9dd27edb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20

Showing all locks held in the system:
2 locks held by kworker/u4:1/21:
#0: ffff8880b9f34cd8 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline]
#0: ffff8880b9f34cd8 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21a/0x2130 kernel/sched/core.c:4440
#1: ffff8880b9f1ff88 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x305/0x440 kernel/sched/psi.c:833
1 lock held by khungtaskd/1628:
#0: ffffffff8b3361a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259
2 locks held by in:imklog/8170:
#0: ffff8880143794f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932
#1: ffff8880b9f34cd8 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline]
#1: ffff8880b9f34cd8 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21a/0x2130 kernel/sched/core.c:4440
1 lock held by syz-executor.4/10332:
#0: ffff88802f2c60e0 (&type->s_umount_key#50/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229

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

NMI backtrace for cpu 0
CPU: 0 PID: 1628 Comm: khungtaskd Not tainted 5.9.0-next-20201023-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+0x107/0x163 lib/dump_stack.c:118
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:147 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
watchdog+0xd89/0xf30 kernel/hung_task.c:339
kthread+0x3af/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2998 Comm: kworker/1:2 Not tainted 5.9.0-next-20201023-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:chacha_permute+0x5a3/0x6f0 lib/crypto/chacha.c:23
Code: 0c 41 c1 c4 08 41 01 dd 44 31 f0 44 89 44 24 14 44 01 e1 45 31 eb c1 c0 07 31 ca 89 4c 24 1c c1 c2 07 41 c1 c3 07 89 44 24 28 <83> 44 24 04 02 89 54 24 24 44 89 5c 24 08 8b 44 24 04 8b 7c 24 38
RSP: 0000:ffffc90001ddf9c0 EFLAGS: 00000002
RAX: 00000000d980da6c RBX: 000000008a97da8b RCX: 00000000b28d400b
RDX: 00000000cc94b0ae RSI: 0000000016ccd74d RDI: 000000008a72d815
RBP: 00000000658b7ed9 R08: 000000008a6c4db3 R09: 000000004afb3d6a
R10: 0000000020685da4 R11: 000000004c778746 R12: 000000000df584d3
R13: 00000000726e3229 R14: 000000009e8f910d R15: 00000000f40eb23e
FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25f53d3000 CR3: 0000000010ea5000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
chacha_block_generic+0x98/0x220 lib/crypto/chacha.c:83
chacha20_block include/crypto/chacha.h:36 [inline]
_extract_crng+0x12f/0x250 drivers/char/random.c:1010
extract_crng drivers/char/random.c:1026 [inline]
_get_random_bytes+0x229/0x670 drivers/char/random.c:1563
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:533 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:562 [inline]
nsim_dev_trap_report_work+0x74e/0xbd0 drivers/net/netdevsim/dev.c:603
process_one_work+0x933/0x15a0 kernel/workqueue.c:2272
worker_thread+0x64c/0x1120 kernel/workqueue.c:2418
kthread+0x3af/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296


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