syzbot


INFO: task hung in __ext4_find_entry

Status: auto-closed as invalid on 2022/07/20 09:42
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 226d, last: 226d

Sample crash report:
INFO: task syz-executor.0:3983 blocked for more than 430 seconds.
      Not tainted 5.18.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:    0 pid: 3983 ppid:  2236 flags:0x00000001
Backtrace: 
[<816f7a50>] (__schedule) from [<816f84d0>] (schedule+0x54/0xbc kernel/sched/core.c:6460)
 r10:816f9058 r9:85228b80 r8:dfd79d8c r7:00000002 r6:82204c2c r5:00000000
 r4:85228b80
[<816f847c>] (schedule) from [<816f8594>] (io_schedule+0x38/0x48 kernel/sched/core.c:8563)
 r5:00000000 r4:85228b80
[<816f855c>] (io_schedule) from [<816f906c>] (bit_wait_io+0x14/0x60 kernel/sched/wait_bit.c:209)
 r5:82204c28 r4:00000002
[<816f9058>] (bit_wait_io) from [<816f8c3c>] (__wait_on_bit+0x94/0x168 kernel/sched/wait_bit.c:49)
 r5:82204c28 r4:dfd79d74
[<816f8ba8>] (__wait_on_bit) from [<816f8d90>] (out_of_line_wait_on_bit+0x80/0xa8 kernel/sched/wait_bit.c:64)
 r10:00000000 r9:00000001 r8:00000001 r7:849d53f8 r6:00000001 r5:84956700
 r4:dfd79d8c
[<816f8d10>] (out_of_line_wait_on_bit) from [<804d9830>] (wait_on_bit_io include/linux/wait_bit.h:101 [inline])
[<816f8d10>] (out_of_line_wait_on_bit) from [<804d9830>] (__wait_on_buffer+0x2c/0x30 fs/buffer.c:122)
 r4:00000000
[<804d9804>] (__wait_on_buffer) from [<805cdf10>] (wait_on_buffer include/linux/buffer_head.h:355 [inline])
[<804d9804>] (__wait_on_buffer) from [<805cdf10>] (__ext4_find_entry+0x298/0x60c fs/ext4/namei.c:1610)
[<805cdc78>] (__ext4_find_entry) from [<805ceb98>] (ext4_lookup_entry fs/ext4/namei.c:1701 [inline])
[<805cdc78>] (__ext4_find_entry) from [<805ceb98>] (ext4_lookup fs/ext4/namei.c:1769 [inline])
[<805cdc78>] (__ext4_find_entry) from [<805ceb98>] (ext4_lookup+0x118/0x350 fs/ext4/namei.c:1760)
 r10:00000053 r9:00000000 r8:849d53f8 r7:00000000 r6:00000600 r5:849d53f8
 r4:8495cd48
[<805cea80>] (ext4_lookup) from [<8049da20>] (__lookup_hash+0x68/0x90 fs/namei.c:1608)
 r9:00000000 r8:849d53f8 r7:dfd79f18 r6:00000600 r5:8495cb28 r4:8495cd48
[<8049d9b8>] (__lookup_hash) from [<804a1968>] (filename_create+0xb8/0x168 fs/namei.c:3703)
 r9:00000000 r8:dfd79f18 r7:00000600 r6:dfd79f5c r5:00000600 r4:00000000
[<804a18b0>] (filename_create) from [<804a513c>] (do_symlinkat+0x50/0x12c fs/namei.c:4316)
 r9:ffffff9c r8:829d9000 r7:829da000 r6:00000000 r5:00088460 r4:829da000
[<804a50ec>] (do_symlinkat) from [<804a52a0>] (__do_sys_symlink fs/namei.c:4348 [inline])
[<804a50ec>] (do_symlinkat) from [<804a52a0>] (sys_symlink+0x40/0x44 fs/namei.c:4346)
 r9:85228b80 r8:802002a4 r7:00000053 r6:000002ce r5:00088460 r4:829da000
[<804a5260>] (sys_symlink) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:64)
Exception stack(0xdfd79fa8 to 0xdfd79ff0)
9fa0:                   00000000 00000000 7ea5f604 00088460 00000000 00000000
9fc0: 00000000 00000000 000002ce 00000053 00120000 7ea5f604 00000000 00000000
9fe0: 00000000 7ea5f534 00020f30 0004b46c
 r5:00000000 r4:00000000
NMI backtrace for cpu 1
CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.18.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace: 
[<816da3f8>] (dump_backtrace) from [<816da728>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:253)
 r7:00000001 r6:00000000 r5:60000093 r4:81d73ca4
[<816da710>] (show_stack) from [<816e3028>] (__dump_stack lib/dump_stack.c:88 [inline])
[<816da710>] (show_stack) from [<816e3028>] (dump_stack_lvl+0x48/0x54 lib/dump_stack.c:106)
[<816e2fe0>] (dump_stack_lvl) from [<816e304c>] (dump_stack+0x18/0x1c lib/dump_stack.c:113)
 r5:00000013 r4:00000001
[<816e3034>] (dump_stack) from [<80810254>] (nmi_cpu_backtrace+0x114/0x180 lib/nmi_backtrace.c:111)
[<80810140>] (nmi_cpu_backtrace) from [<808103f0>] (nmi_trigger_cpumask_backtrace+0x130/0x1d0 lib/nmi_backtrace.c:62)
 r7:00000001 r6:8220c494 r5:8220ccd0 r4:00000000
[<808102c0>] (nmi_trigger_cpumask_backtrace) from [<8021110c>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:863)
 r9:0000d704 r8:82204d00 r7:00007f62 r6:8248992c r5:8220c5e4 r4:84044840
[<802110f4>] (arch_trigger_cpumask_backtrace) from [<8032b534>] (trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline])
[<802110f4>] (arch_trigger_cpumask_backtrace) from [<8032b534>] (check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline])
[<802110f4>] (arch_trigger_cpumask_backtrace) from [<8032b534>] (watchdog+0x4a0/0x58c kernel/hung_task.c:369)
[<8032b094>] (watchdog) from [<8026ac14>] (kthread+0xf0/0x120 kernel/kthread.c:376)
 r10:00000000 r9:df81de4c r8:82aebb80 r7:00000000 r6:8032b094 r5:829f9700
 r4:82aebac0
[<8026ab24>] (kthread) from [<80200100>] (ret_from_fork+0x14/0x34 arch/arm/kernel/entry-common.S:148)
Exception stack(0xdf8e9fb0 to 0xdf8e9ff8)
9fa0:                                     00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8026ab24 r4:82aebac0
Sending NMI from CPU 1 to CPUs 0:

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-qemu2-arm32 2022/04/21 09:33 upstream b253435746d9 d4befee1 .config log report info INFO: task hung in __ext4_find_entry
* Struck through repros no longer work on HEAD.