Hi,
We would like to report the following bug which has been found by our
modified version of syzkaller.
======================================================
description: INFO: task hung in ocfs2_get_sector
affected file: drivers/block/floppy.c
kernel version: 5.15.159
kernel commit: a38297e3fb012ddfa7ce0321a7e5a8daeb1872b6
git tree: upstream
kernel config: attached
crash reproducer: attached
======================================================
Crash log:
INFO: task syz-executor.4:92137 blocked for more than 143 seconds.
Not tainted 5.15.159 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:27168 pid:92137 ppid: 6651 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xb54/0x5560 kernel/sched/core.c:6376
schedule+0x113/0x240 kernel/sched/core.c:6459
io_schedule+0xba/0x130 kernel/sched/core.c:8484
bit_wait_io+0x12/0xd0 kernel/sched/wait_bit.c:209
__wait_on_bit+0x60/0x190 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0xd8/0x110 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
__wait_on_buffer+0x7c/0x90 fs/buffer.c:122
wait_on_buffer include/linux/buffer_head.h:390 [inline]
ocfs2_get_sector+0x34d/0x540 fs/ocfs2/super.c:1772
ocfs2_sb_probe fs/ocfs2/super.c:748 [inline]
ocfs2_fill_super+0x3d5/0x3cc0 fs/ocfs2/super.c:989
mount_bdev+0x34f/0x410 fs/super.c:1387
legacy_get_tree+0x105/0x220 fs/fs_context.c:611
vfs_get_tree+0x89/0x2f0 fs/super.c:1517
do_new_mount fs/namespace.c:3005 [inline]
path_mount+0x6a5/0x2010 fs/namespace.c:3335
do_mount fs/namespace.c:3348 [inline]
__do_sys_mount fs/namespace.c:3556 [inline]
__se_sys_mount fs/namespace.c:3533 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3533
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb030b75dad
RSP: 002b:00007fb02f0c4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb030cb3050 RCX: 00007fb030b75dad
RDX: 0000000020000080 RSI: 0000000020000000 RDI: 00000000200000c0
RBP: 00007fb030bd74a6 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb030cb3050 R15: 00007fb02f0a4000
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8b9876c0 (rcu_read_lock){....}-{1:2}, at:
debug_show_all_locks+0x53/0x272 kernel/locking/lockdep.c:6452
2 locks held by systemd-journal/3015:
1 lock held by in:imklog/6431:
#0: ffff888152c46870 (&f->f_pos_lock){+.+.}-{3:3}, at:
__fdget_pos+0xed/0x190 fs/file.c:1088
1 lock held by syz-executor.4/92137:
#0: ffff8880792300e0 (&type->s_umount_key#105/1){+.+.}-{3:3}, at:
alloc_super+0x233/0xb70 fs/super.c:229
2 locks held by syz-executor.4/92619:
#0: ffff88801774f008 (&bdev->bd_fsfreeze_mutex){+.+.}-{3:3}, at:
mount_bdev+0x90/0x410 fs/super.c:1354
#1: ffff8880792300e0 (&type->s_umount_key#115){+.+.}-{3:3}, at:
grab_super+0x59/0x260 fs/super.c:389
1 lock held by syz-executor.4/92621:
#0: ffff88801ab2e208 (&nbd->config_lock){+.+.}-{3:3}, at:
nbd_ioctl+0x151/0xba0 drivers/block/nbd.c:1460
1 lock held by syz-executor.4/92622:
#0: ffff88801ab2e208 (&nbd->config_lock){+.+.}-{3:3}, at:
nbd_ioctl+0x151/0xba0 drivers/block/nbd.c:1460
1 lock held by syz-executor.4/93058:
#0: ffff88801ab2e208 (&nbd->config_lock){+.+.}-{3:3}, at:
nbd_ioctl+0x151/0xba0 drivers/block/nbd.c:1460
1 lock held by syz-executor.4/93059:
#0: ffff88801ab2e208 (&nbd->config_lock){+.+.}-{3:3}, at:
nbd_ioctl+0x151/0xba0 drivers/block/nbd.c:1460
1 lock held by syz-executor.4/93060:
#0: ffff88801ab2e208 (&nbd->config_lock){+.+.}-{3:3}, at:
nbd_ioctl+0x151/0xba0 drivers/block/nbd.c:1460
1 lock held by syz-executor.4/93061:
#0: ffff88801774f008 (&bdev->bd_fsfreeze_mutex){+.+.}-{3:3}, at:
mount_bdev+0x90/0x410 fs/super.c:1354
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 30 Comm: khungtaskd Not tainted 5.15.159 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1ea/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xc5f/0xf30 kernel/hung_task.c:295
kthread+0x3e5/0x4d0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 34028 Comm: kworker/u4:6 Not tainted 5.15.159 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x1ab/0x5340 kernel/locking/lockdep.c:4918
Code: 0f 84 e1 10 00 00 48 ba ab aa aa aa aa aa aa aa 48 2d 40 7e d9
8f 48 8d bd f0 0a 00 00 48 c1 f8 06 48 0f af c2 48 89 7c 24 28 <48> 89
44 24 10 8b 44 24 08 48 89 c6 48 8d 04 80 85 f6 4c 8d 24 c5
RSP: 0000:ffffc9000737fa38 EFLAGS: 00000803
RAX: 0000000000000015 RBX: 0000000000000000 RCX: 0000000000000000
RDX: aaaaaaaaaaaaaaab RSI: 0000000000000000 RDI: ffff88801a762f30
RBP: ffff88801a762440 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff90582768 R12: 0000000000000000
R13: ffffffff8b9876c0 R14: 0000000000000000 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff88823bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc544a1d4a8 CR3: 0000000147ec5000 CR4: 0000000000750ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<NMI>
</NMI>
<TASK>
lock_acquire kernel/locking/lockdep.c:5623 [inline]
lock_acquire+0x1ab/0x4e0 kernel/locking/lockdep.c:5588
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:739 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x12d/0xfe0 net/batman-adv/network-coding.c:723
process_one_work+0x9bc/0x1550 kernel/workqueue.c:2310
worker_thread+0x65d/0x1130 kernel/workqueue.c:2457
kthread+0x3e5/0x4d0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>
======================================================
Wishing you a nice day!
Best,
Marius