syzbot


INFO: task hung in ext4_punch_hole

Status: auto-closed as invalid on 2019/03/25 18:21
First crash: 2033d, last: 2033d

Sample crash report:
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
INFO: task syz-executor0:18361 blocked for more than 140 seconds.
      Not tainted 4.9.129+ #95
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D27600 18361   2091 0x00000004
 ffff8801cd37df00 ffff8801d211cd00 ffff8801a8734200 ffff8801d4350000
 ffff8801db621018 ffff8801a9acfa90 ffffffff827e7d32 ffff8801a9acfa68
 ffffffff81206807 0000000000000000 00ff8801cd37e7a8 ffff8801db6218f0
Call Trace:
 [<ffffffff827e925f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff827f301a>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff827f301a>] rwsem_down_write_failed+0x39a/0x730 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81b5e137>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff827f1e4c>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff827f1e4c>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff816d9116>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff816d9116>] ext4_punch_hole+0x126/0xf40 fs/ext4/inode.c:4017
 [<ffffffff8178a030>] ext4_fallocate+0x350/0x1e80 fs/ext4/extents.c:4951
 [<ffffffff815010bd>] vfs_fallocate+0x35d/0x620 fs/open.c:329
 [<ffffffff81503f63>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff81503f63>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff827f7f93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131b83c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131b83c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fdfe4>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2024:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff827f6082>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81d1fe52>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
3 locks held by kworker/u4:5/6985:
 #0:  ("writeback"){++++.+}, at: [<ffffffff81130abc>] process_one_work+0x73c/0x1530 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff81130af4>] process_one_work+0x774/0x1530 kernel/workqueue.c:2089
 #2:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8143395f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2331
1 lock held by syz-executor0/18357:
 #0:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8143395f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2331
2 locks held by syz-executor0/18361:
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150105e>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150105e>] vfs_fallocate+0x2fe/0x620 fs/open.c:328
 #1:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816d9116>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816d9116>] ext4_punch_hole+0x126/0xf40 fs/ext4/inode.c:4017
2 locks held by syz-executor0/18369:
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150105e>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150105e>] vfs_fallocate+0x2fe/0x620 fs/open.c:328
 #1:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816d9116>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816d9116>] ext4_punch_hole+0x126/0xf40 fs/ext4/inode.c:4017
4 locks held by syz-executor0/18380:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156c9ec>] __fdget_pos+0xac/0xd0 fs/file.c:781
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150ab6b>] file_start_write include/linux/fs.h:2640 [inline]
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150ab6b>] vfs_write+0x3eb/0x520 fs/read_write.c:556
 #2:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816b29e2>] inode_lock include/linux/fs.h:766 [inline]
 #2:  (&sb->s_type->i_mutex_key#10){++++++}, at: [<ffffffff816b29e2>] ext4_file_write_iter+0x122/0xd70 fs/ext4/file.c:100
 #3:  (&type->s_umount_key#32){++++++}, at: [<ffffffff815a1869>] try_to_writeback_inodes_sb_nr+0x29/0x70 fs/fs-writeback.c:2358
1 lock held by syz-executor0/18395:
 #0:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8143395f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2331

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.129+ #95
 ffff8801d9907d08 ffffffff81b2bbb9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff81098180 ffff8801d9907d40
 ffffffff81b36cc9 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b2bbb9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b2bbb9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b36cc9>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b36c5c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff81098284>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131bdcd>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131bdcd>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131bdcd>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131bdcd>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8114272d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff827f815c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff827f6bc6

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/26 18:17 https://android.googlesource.com/kernel/common android-4.9 b727d1c1a64f 455b6354 .config console log report ci-android-49-kasan-gce
* Struck through repros no longer work on HEAD.