syzbot


INFO: task hung in d_alloc_parallel (2)

Status: upstream: reported C repro on 2024/11/04 12:30
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+30f73869d6de512e814b@syzkaller.appspotmail.com
First crash: 39d, last: 4d22h
Bug presence (2)
Date Name Commit Repro Result
2024/11/09 linux-6.1.y (ToT) d7039b844a1c C [report] INFO: task hung in d_alloc_parallel
2024/11/09 upstream (ToT) da4373fbcf00 C Didn't crash
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in d_alloc_parallel 85 1920d 2070d 0/3 auto-closed as invalid on 2020/01/08 20:52
linux-5.15 INFO: task hung in d_alloc_parallel origin:upstream C 73 10d 239d 0/3 upstream: reported C repro on 2024/04/18 05:41
linux-4.14 INFO: task hung in d_alloc_parallel C error 4 1339d 1948d 0/1 upstream: reported C repro on 2019/08/14 00:43
android-414 INFO: task hung in d_alloc_parallel 1 1880d 1880d 0/1 auto-closed as invalid on 2020/02/18 04:29
linux-4.19 INFO: task hung in d_alloc_parallel vfs C error 5 669d 1686d 0/1 upstream: reported C repro on 2020/05/01 20:49
upstream INFO: task hung in d_alloc_parallel fuse 213 2114d 2445d 0/28 closed as dup on 2018/09/08 15:40
linux-6.1 INFO: task hung in d_alloc_parallel 43 119d 242d 0/3 auto-obsoleted due to no activity on 2024/10/24 17:53
upstream INFO: task hung in d_alloc_parallel (2) fs C done error 1380 4d03h 1878d 0/28 upstream: reported C repro on 2019/10/22 22:44

Sample crash report:
INFO: task syz-executor299:4306 blocked for more than 143 seconds.
      Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
 stack:0     pid:4306  ppid:4291   flags:0x00000005
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
 d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
 __lookup_slow+0x108/0x374 fs/namei.c:1675
 lookup_slow+0x60/0x84 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x830/0xcc8 fs/namei.c:2325
 path_openat+0x1c8/0x2548 fs/namei.c:3779
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4307 blocked for more than 143 seconds.
      Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
 stack:0     pid:4307  ppid:4294   flags:0x00000005
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
 d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
 __lookup_slow+0x108/0x374 fs/namei.c:1675
 lookup_slow+0x60/0x84 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x830/0xcc8 fs/namei.c:2325
 path_openat+0x1c8/0x2548 fs/namei.c:3779
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4308 blocked for more than 143 seconds.
      Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
 stack:0     pid:4308  ppid:4292   flags:0x00000005
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
 d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
 __lookup_slow+0x108/0x374 fs/namei.c:1675
 lookup_slow+0x60/0x84 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x830/0xcc8 fs/namei.c:2325
 path_openat+0x1c8/0x2548 fs/namei.c:3779
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4312 blocked for more than 143 seconds.
      Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
 stack:0     pid:4312  ppid:4293   flags:0x00000005
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
 d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
 __lookup_slow+0x108/0x374 fs/namei.c:1675
 lookup_slow+0x60/0x84 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x830/0xcc8 fs/namei.c:2325
 path_openat+0x1c8/0x2548 fs/namei.c:3779
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: 
ffff800015ba5bf0
 (
rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: 
ffff800015ba63f0
 (
rcu_tasks_trace.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: 
ffff800015ba5a20
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/4055:
 #0: 
ffff0000d66f2098
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: 
ffff80001efd02f0
 (
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2198
4 locks held by syz-executor299/4296:
1 lock held by syz-executor299/4306:
 #0: 
ffff0000e4878198
 (&type->i_mutex_dir_key#6){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4299:
1 lock held by syz-executor299/4307:
 #0: ffff0000e4878c48
 (&type->i_mutex_dir_key#6){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4301:
1 lock held by syz-executor299/4308:
 #0: 
ffff0000e48796f8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
ffff0000e48796f8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4304:
1 lock held by syz-executor299/4312:
 #0: 
ffff0000e487a1a8
 (
&type->i_mutex_dir_key
#6
){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4311:

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


Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/04 12:29 linux-6.1.y 7c15117f9468 f00eed24 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 INFO: task hung in d_alloc_parallel
2024/12/08 14:47 linux-6.1.y e4d90d63d385 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in d_alloc_parallel
2024/11/18 21:33 linux-6.1.y b67dc5c9ade9 e7bb5d6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in d_alloc_parallel
* Struck through repros no longer work on HEAD.