syzbot


INFO: task hung in ext4_direct_IO

Status: auto-closed as invalid on 2019/09/23 12:02
Reported-by: syzbot+8276d5dd1fd7d7629adc@syzkaller.appspotmail.com
First crash: 1943d, last: 1878d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ext4_direct_IO ext4 1 2196d 2195d 0/26 closed as dup on 2018/07/18 11:49
android-49 INFO: task hung in ext4_direct_IO 1 1887d 1861d 0/3 auto-closed as invalid on 2019/09/14 20:30

Sample crash report:
ip6_tunnel: l0 xmit: Local address not yet configured!
INFO: task syz-executor.0:1446 blocked for more than 140 seconds.
      Not tainted 4.14.108+ #39
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D25496  1446   1851 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:276 [inline]
 rwsem_down_read_failed+0x21f/0x3c0 kernel/locking/rwsem-xadd.c:293
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 inode_lock_shared include/linux/fs.h:725 [inline]
 ext4_direct_IO_read fs/ext4/inode.c:3798 [inline]
 ext4_direct_IO+0x546/0x2800 fs/ext4/inode.c:3862
 generic_file_read_iter+0x24a/0x1a90 mm/filemap.c:2257
 ext4_file_read_iter+0x119/0x180 fs/ext4/file.c:75
 call_read_iter include/linux/fs.h:1778 [inline]
 generic_file_splice_read+0x30d/0x540 fs/splice.c:307
 do_splice_to+0xfd/0x150 fs/splice.c:880
 splice_direct_to_actor+0x21a/0x760 fs/splice.c:952
 do_splice_direct+0x177/0x240 fs/splice.c:1061
 do_sendfile+0x493/0xb20 fs/read_write.c:1438
 SYSC_sendfile64 fs/read_write.c:1493 [inline]
 SyS_sendfile64+0xab/0x140 fs/read_write.c:1485
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.?}, at: [<ffffffffafa010ac>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1758:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffffb053a3e2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffb0535807>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.0/1446:
 #0:  (sb_writers#4){.+.+}, at: [<ffffffffafd58e3f>] file_start_write include/linux/fs.h:2726 [inline]
 #0:  (sb_writers#4){.+.+}, at: [<ffffffffafd58e3f>] do_sendfile+0x88f/0xb20 fs/read_write.c:1437
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<ffffffffaff58306>] inode_lock_shared include/linux/fs.h:725 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<ffffffffaff58306>] ext4_direct_IO_read fs/ext4/inode.c:3798 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++}, at: [<ffffffffaff58306>] ext4_direct_IO+0x546/0x2800 fs/ext4/inode.c:3862

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.108+ #39
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1011 Comm: syz-executor.4 Not tainted 4.14.108+ #39
task: ffff88819f8c0000 task.stack: ffff88816add0000
RIP: 0033:0x4015a4
RSP: 002b:00007ff769845690 EFLAGS: 00000202
RAX: 0000000060f94762 RBX: 000000000000000b RCX: 0000000000458209
RDX: 0000000000000000 RSI: 00007ff7698456c0 RDI: 000000000000000b
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007ff769846700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c423558018 CR3: 00000001626b0004 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/03/27 12:01 android-4.14 db689dd813b7 55684ce1 .config console log report ci-android-414-kasan-gce-root
2019/03/26 12:21 android-4.14 02b246355459 55684ce1 .config console log report ci-android-414-kasan-gce-root
2019/03/24 19:33 android-4.14 4344de2f79ab acbc5b7d .config console log report ci-android-414-kasan-gce-root
2019/03/16 01:52 android-4.14 8ed9bc6e6401 bab43553 .config console log report ci-android-414-kasan-gce-root
2019/03/14 06:44 android-4.14 8ed9bc6e6401 d09a902e .config console log report ci-android-414-kasan-gce-root
2019/02/13 02:00 android-4.14 09518493514e 1eedba36 .config console log report ci-android-414-kasan-gce-root
2019/02/01 21:03 android-4.14 80d7b06534fa 564f9a4f .config console log report ci-android-414-kasan-gce-root
2019/01/21 13:30 android-4.14 5a76363f1262 badbbeee .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.