syzbot


INFO: task hung in iterate_supers

Status: auto-closed as invalid on 2020/05/29 21:42
Reported-by: syzbot+f6f3a910fd426719ea8d@syzkaller.appspotmail.com
First crash: 1282d, last: 1095d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in iterate_supers 1 1552d 1390d 0/1 auto-closed as invalid on 2019/04/28 09:45
linux-4.14 INFO: task hung in iterate_supers 16 760d 1375d 0/1 auto-closed as invalid on 2021/04/29 12:11
linux-4.19 INFO: task hung in iterate_supers (2) 1 962d 962d 0/1 auto-closed as invalid on 2020/10/09 12:15
upstream INFO: task hung in iterate_supers reiserfs vfs exfat ntfs3 gfs2 xfs ntfs C error 727 1h26m 1664d 0/24 upstream: reported C repro on 2018/07/10 10:30
linux-4.19 INFO: task hung in iterate_supers (3) vfs reiserfs syz 338 11h35m 770d 0/1 upstream: reported syz repro on 2020/12/20 03:38
android-49 INFO: task hung in iterate_supers 19 1614d 1714d 0/3 auto-closed as invalid on 2019/02/25 14:49
android-414 INFO: task hung in iterate_supers (2) 1 1371d 1371d 0/1 auto-closed as invalid on 2019/10/25 08:49

Sample crash report:
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task syz-executor.2:14783 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D29944 14783   8193 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x21b/0x3c0 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 down_read+0x49/0xb0 kernel/locking/rwsem.c:26
 iterate_supers+0xe2/0x290 fs/super.c:631
 ksys_sync+0x90/0x160 fs/sync.c:113
 __ia32_sys_sync+0xe/0x20 fs/sync.c:124
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: Bad RIP value.
RSP: 002b:00007f134990ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f134990f6d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000b6d R14: 00000000004c94df R15: 000000000075bf2c
INFO: task syz-executor.2:14786 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D29896 14786   8193 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x21b/0x3c0 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 down_read+0x49/0xb0 kernel/locking/rwsem.c:26
 iterate_supers+0xe2/0x290 fs/super.c:631
 ksys_sync+0x90/0x160 fs/sync.c:113
 __ia32_sys_sync+0xe/0x20 fs/sync.c:124
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: Bad RIP value.
RSP: 002b:00007f13498edc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f13498ee6d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000b6d R14: 00000000004c94df R15: 000000000075bfd4

Showing all locks held in the system:
1 lock held by khungtaskd/1080:
 #0: 00000000c83ca7b6 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by rsyslogd/8025:
 #0: 000000002ab9e108 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/8149:
 #0: 00000000367b2234 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000008a050270 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8150:
 #0: 0000000070de0b6c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000005d1b193 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8151:
 #0: 00000000cdf1fd5f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000079859824 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8152:
 #0: 000000000b37b171 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000dbd19d58 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8153:
 #0: 0000000031337d37 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000009da66f8b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8154:
 #0: 00000000aaeccdf3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000050647b8c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8155:
 #0: 0000000086bfc3f7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000008c5748b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
1 lock held by syz-executor.2/11058:
1 lock held by syz-executor.2/14783:
 #0: 00000000ca5ddf1c (&type->s_umount_key#82){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:631
1 lock held by syz-executor.2/14786:
 #0: 00000000ca5ddf1c (&type->s_umount_key#82){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:631

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

NMI backtrace for cpu 1
CPU: 1 PID: 1080 Comm: khungtaskd Not tainted 4.19.100-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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11058 Comm: syz-executor.2 Not tainted 4.19.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
Code: 90 90 90 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 28 e9 96 7e 81 e2 00 01 1f 00 75 2b 8b 90 d0 12 00 00 <83> fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12 00 00 48 8b 11 48
RSP: 0018:ffff88804ad4f658 EFLAGS: 00000246
RAX: ffff8880840942c0 RBX: ffff888099186888 RCX: ffffffff81ba5a7e
RDX: 0000000000000000 RSI: ffffffff81ba5a8c RDI: 0000000000000001
RBP: ffff88804ad4f658 R08: ffff8880840942c0 R09: 0000000000000001
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: dffffc0000000000
R13: 0000000000000005 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f134990f700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 0000000090065000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 init_page_buffers+0x24c/0x470 fs/buffer.c:903
 grow_dev_page fs/buffer.c:955 [inline]
 grow_buffers fs/buffer.c:1017 [inline]
 __getblk_slow fs/buffer.c:1044 [inline]
 __getblk_gfp+0x836/0xa30 fs/buffer.c:1321
 __bread_gfp+0x2f/0x300 fs/buffer.c:1355
 sb_bread include/linux/buffer_head.h:307 [inline]
 udf_tread+0xf1/0x140 fs/udf/misc.c:44
 udf_read_tagged+0x50/0x530 fs/udf/misc.c:210
 udf_check_anchor_block+0x1ef/0x680 fs/udf/super.c:1810
 udf_scan_anchors+0x3f4/0x680 fs/udf/super.c:1872
 udf_find_anchor fs/udf/super.c:1907 [inline]
 udf_load_vrs+0x67f/0xc80 fs/udf/super.c:1972
 udf_fill_super+0x7c0/0x16e5 fs/udf/super.c:2167
 mount_bdev+0x304/0x3c0 fs/super.c:1158
 udf_mount+0x35/0x40 fs/udf/super.c:131
 mount_fs+0xa8/0x31f fs/super.c:1261
 vfs_kern_mount.part.0+0x6f/0x410 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x53e/0x2bc0 fs/namespace.c:2799
 ksys_mount+0xdb/0x150 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3026
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f134990ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f134990f6d4 RCX: 000000000045b349
RDX: 0000000020000080 RSI: 0000000020000480 RDI: 0000000020000100
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000744 R14: 00000000004c8bd8 R15: 000000000075bf2c

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-19 2020/01/30 21:42 linux-4.19.y 7cdefde351b6 5ed23f9a .config console log report
ci2-linux-4-19 2019/12/29 15:52 linux-4.19.y 672481c2deff af6b8ef8 .config console log report
ci2-linux-4-19 2019/12/26 11:32 linux-4.19.y 672481c2deff be5c2c81 .config console log report
ci2-linux-4-19 2019/11/14 09:46 linux-4.19.y c555efaf1402 048f2d49 .config console log report
ci2-linux-4-19 2019/10/20 22:35 linux-4.19.y c3038e718a19 8c88c9c1 .config console log report
ci2-linux-4-19 2019/10/05 23:28 linux-4.19.y 6cad9d0cf87b f3f7d9c8 .config console log report
ci2-linux-4-19 2019/07/27 14:05 linux-4.19.y 7250956f6eaf c85e1c5b .config console log report
* Struck through repros no longer work on HEAD.