syzbot


INFO: task hung in __bread_gfp (3)

Status: auto-closed as invalid on 2022/02/04 04:37
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 392d, last: 392d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __bread_gfp 4 1609d 1704d 0/24 auto-closed as invalid on 2019/02/22 10:29
android-49 INFO: task hung in __bread_gfp 2 1691d 1704d 0/3 auto-closed as invalid on 2019/02/22 14:34
upstream INFO: task hung in __bread_gfp (2) 5 926d 933d 0/24 auto-closed as invalid on 2020/07/20 01:01

Sample crash report:
INFO: task syz-executor.3:6245 blocked for more than 143 seconds.
      Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:26360 pid: 6245 ppid: 14038 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4969 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6250
 schedule+0x12b/0x1f0 kernel/sched/core.c:6323
 io_schedule+0x83/0x100 kernel/sched/core.c:8368
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0xbd/0x190 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x1d2/0x250 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 __wait_on_buffer fs/buffer.c:122 [inline]
 wait_on_buffer include/linux/buffer_head.h:356 [inline]
 __bread_slow fs/buffer.c:1181 [inline]
 __bread_gfp+0x296/0x360 fs/buffer.c:1382
 sb_bread include/linux/buffer_head.h:303 [inline]
 efs_fill_super+0x165/0x1440 fs/efs/super.c:272
 mount_bdev+0x26c/0x3a0 fs/super.c:1368
 legacy_get_tree+0xea/0x180 fs/fs_context.c:610
 vfs_get_tree+0x86/0x270 fs/super.c:1498
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1986/0x2c30 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc4b80a0ae9
RSP: 002b:00007fc4b5616188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc4b81b3f60 RCX: 00007fc4b80a0ae9
RDX: 00000000200006c0 RSI: 0000000020000680 RDI: 0000000020000640
RBP: 00007fc4b80faf25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb59f7e9f R14: 00007fc4b5616300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.3:6260 blocked for more than 143 seconds.
      Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:27088 pid: 6260 ppid: 14038 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4969 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6250
 schedule+0x12b/0x1f0 kernel/sched/core.c:6323
 blk_mq_freeze_queue_wait+0x105/0x190 block/blk-mq.c:178
 nbd_add_socket+0x17b/0x8e0 drivers/block/nbd.c:1107
 __nbd_ioctl drivers/block/nbd.c:1464 [inline]
 nbd_ioctl+0x263/0xb80 drivers/block/nbd.c:1521
 blkdev_ioctl+0x3ac/0x790 block/ioctl.c:597
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc4b80a0ae9
RSP: 002b:00007fc4b55d4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc4b81b40e0 RCX: 00007fc4b80a0ae9
RDX: 0000000000000006 RSI: 000000000000ab00 RDI: 0000000000000005
RBP: 00007fc4b80faf25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb59f7e9f R14: 00007fc4b55d4300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.3:6265 blocked for more than 144 seconds.
      Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:25616 pid: 6265 ppid: 14038 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4969 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6250
 schedule+0x12b/0x1f0 kernel/sched/core.c:6323
 rwsem_down_write_slowpath+0xd47/0x1440 kernel/locking/rwsem.c:1117
 __down_write_common kernel/locking/rwsem.c:1272 [inline]
 __down_write kernel/locking/rwsem.c:1281 [inline]
 down_write+0x163/0x170 kernel/locking/rwsem.c:1528
 grab_super+0x58/0x190 fs/super.c:389
 sget+0x1bd/0x4f0 fs/super.c:606
 mount_bdev+0xe8/0x3a0 fs/super.c:1341
 legacy_get_tree+0xea/0x180 fs/fs_context.c:610
 vfs_get_tree+0x86/0x270 fs/super.c:1498
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1986/0x2c30 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc4b80a0ae9
RSP: 002b:00007fc4b55b3188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc4b81b41a0 RCX: 00007fc4b80a0ae9
RDX: 00000000200006c0 RSI: 0000000020000680 RDI: 0000000020000640
RBP: 00007fc4b80faf25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb59f7e9f R14: 00007fc4b55b3300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1d8c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by in:imklog/6144:
2 locks held by kworker/u4:0/16471:
1 lock held by syz-executor.3/6245:
 #0: ffff888034c4a0e0 (&type->s_umount_key#100/1){+.+.}-{3:3}, at: alloc_super+0x1c8/0x860 fs/super.c:229
1 lock held by syz-executor.3/6260:
 #0: ffff88801afea198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x148/0xb80 drivers/block/nbd.c:1514
2 locks held by syz-executor.3/6265:
 #0: ffff888146191dd8 (&bdev->bd_fsfreeze_mutex){+.+.}-{3:3}, at: mount_bdev+0x88/0x3a0 fs/super.c:1335
 #1: ffff888034c4a0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: grab_super+0x58/0x190 fs/super.c:389

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc82/0xcd0 kernel/hung_task.c:295
 kthread+0x468/0x490 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 16471 Comm: kworker/u4:0 Not tainted 5.15.0-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_release kernel/locking/lockdep.c:5288 [inline]
RIP: 0010:lock_release+0x194/0x810 kernel/locking/lockdep.c:5645
Code: 00 48 c7 c0 14 43 fd 8d 48 c1 e8 03 42 8a 04 20 84 c0 0f 85 fb 04 00 00 83 3d ab 62 97 0c 00 0f 84 83 03 00 00 48 8b 44 24 10 <48> 8d b8 58 0a 00 00 48 89 fe 48 c1 ee 03 42 8a 04 26 84 c0 0f 85
RSP: 0000:ffffc90004207a00 EFLAGS: 00000002
RAX: ffff88801a298000 RBX: 1ffff92000840f56 RCX: ffffc90004207a03
RDX: 1ffff92000840f50 RSI: 0000000000000201 RDI: 0000000000000000
RBP: ffffc90004207b38 R08: dffffc0000000000 R09: fffffbfff1bfa1ee
R10: fffffbfff1bfa1ee R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000840f4c R14: ffffffff89de2d1f R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd1114456b5 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline]
 _raw_spin_unlock_bh+0x17/0x30 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:395 [inline]
 batadv_nc_purge_paths+0x35f/0x3f0 net/batman-adv/network-coding.c:475
 batadv_nc_worker+0x31e/0x5b0 net/batman-adv/network-coding.c:726
 process_one_work+0x853/0x1140 kernel/workqueue.c:2298
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2445
 kthread+0x468/0x490 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 48 c7             	add    %cl,-0x39(%rax)
   3:	c0 14 43 fd          	rclb   $0xfd,(%rbx,%rax,2)
   7:	8d 48 c1             	lea    -0x3f(%rax),%ecx
   a:	e8 03 42 8a 04       	callq  0x48a4212
   f:	20 84 c0 0f 85 fb 04 	and    %al,0x4fb850f(%rax,%rax,8)
  16:	00 00                	add    %al,(%rax)
  18:	83 3d ab 62 97 0c 00 	cmpl   $0x0,0xc9762ab(%rip)        # 0xc9762ca
  1f:	0f 84 83 03 00 00    	je     0x3a8
  25:	48 8b 44 24 10       	mov    0x10(%rsp),%rax
* 2a:	48 8d b8 58 0a 00 00 	lea    0xa58(%rax),%rdi <-- trapping instruction
  31:	48 89 fe             	mov    %rdi,%rsi
  34:	48 c1 ee 03          	shr    $0x3,%rsi
  38:	42 8a 04 26          	mov    (%rsi,%r12,1),%al
  3c:	84 c0                	test   %al,%al
  3e:	0f                   	.byte 0xf
  3f:	85                   	.byte 0x85

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/11/06 04:32 upstream fe91c4725aee 4c1be0be .config log report info INFO: task hung in __bread_gfp
* Struck through repros no longer work on HEAD.