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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: 195d, last: 2d09h
Fix bisection: failed (error log, bisect log)
  
▶ ▼ 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 2077d 2226d 0/3 auto-closed as invalid on 2020/01/08 20:52
linux-5.15 INFO: task hung in d_alloc_parallel origin:upstream missing-backport C error 77 12d 395d 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 1495d 2104d 0/1 upstream: reported C repro on 2019/08/14 00:43
android-414 INFO: task hung in d_alloc_parallel 1 2036d 2036d 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 826d 1843d 0/1 upstream: reported C repro on 2020/05/01 20:49
upstream INFO: task hung in d_alloc_parallel fuse 213 2270d 2601d 0/28 closed as dup on 2018/09/08 15:40
linux-6.1 INFO: task hung in d_alloc_parallel 43 276d 398d 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 1411 64d 2034d 0/28 upstream: reported C repro on 2019/10/22 22:44
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2025/04/20 07:53 18m fix candidate upstream error job log
2025/03/02 13:58 16m fix candidate upstream error job log
2025/02/11 17:42 15m bisect fix linux-6.1.y error job log

Sample crash report:
INFO: task syz-executor397:4339 blocked for more than 143 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor397 state:D stack:0     pid:4339  ppid:4324   flags:0x00000005
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 d_wait_lookup+0x154/0x22c fs/dcache.c:2632
 d_alloc_parallel+0x978/0x10e4 fs/dcache.c:2714
 __lookup_slow+0x104/0x370 fs/namei.c:1675
 lookup_slow+0x5c/0x80 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x76c/0xc6c fs/namei.c:2325
 path_openat+0x1c0/0x2680 fs/namei.c:3779
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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-executor397:4341 blocked for more than 143 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor397 state:D stack:0     pid:4341  ppid:4326   flags:0x00000005
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 d_wait_lookup+0x154/0x22c fs/dcache.c:2632
 d_alloc_parallel+0x978/0x10e4 fs/dcache.c:2714
 __lookup_slow+0x104/0x370 fs/namei.c:1675
 lookup_slow+0x5c/0x80 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x76c/0xc6c fs/namei.c:2325
 path_openat+0x1c0/0x2680 fs/namei.c:3779
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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-executor397:4340 blocked for more than 143 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor397 state:D stack:0     pid:4340  ppid:4325   flags:0x00000005
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 d_wait_lookup+0x154/0x22c fs/dcache.c:2632
 d_alloc_parallel+0x978/0x10e4 fs/dcache.c:2714
 __lookup_slow+0x104/0x370 fs/namei.c:1675
 lookup_slow+0x5c/0x80 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x76c/0xc6c fs/namei.c:2325
 path_openat+0x1c0/0x2680 fs/namei.c:3779
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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-executor397:4343 blocked for more than 143 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor397 state:D stack:0     pid:4343  ppid:4323   flags:0x00000005
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 d_wait_lookup+0x154/0x22c fs/dcache.c:2632
 d_alloc_parallel+0x978/0x10e4 fs/dcache.c:2714
 __lookup_slow+0x104/0x370 fs/namei.c:1675
 lookup_slow+0x5c/0x80 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x76c/0xc6c fs/namei.c:2325
 path_openat+0x1c0/0x2680 fs/namei.c:3779
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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-executor397:4342 blocked for more than 143 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor397 state:D stack:0     pid:4342  ppid:4327   flags:0x00000005
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 d_wait_lookup+0x154/0x22c fs/dcache.c:2632
 d_alloc_parallel+0x978/0x10e4 fs/dcache.c:2714
 __lookup_slow+0x104/0x370 fs/namei.c:1675
 lookup_slow+0x5c/0x80 fs/namei.c:1707
 walk_component fs/namei.c:1998 [inline]
 link_path_walk+0x76c/0xc6c fs/namei.c:2325
 path_openat+0x1c0/0x2680 fs/namei.c:3779
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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: ffff800015247630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015247e50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffff800015246cc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/4065:
 #0: ffff0000d5f8b098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff8000205fe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2ec/0xf9c drivers/tty/n_tty.c:2198
2 locks held by syz-executor397/4330:
1 lock held by syz-executor397/4339:
 #0: ffff0000e22b4188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff0000e22b4188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x4c/0x80 fs/namei.c:1706
2 locks held by syz-executor397/4331:
1 lock held by syz-executor397/4341:
 #0: ffff0000e2374188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff0000e2374188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x4c/0x80 fs/namei.c:1706
1 lock held by syz-executor397/4334:
1 lock held by syz-executor397/4340:
 #0: ffff0000e23746d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff0000e23746d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x4c/0x80 fs/namei.c:1706
1 lock held by syz-executor397/4336:
1 lock held by syz-executor397/4343:
 #0: ffff0000e22b46d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff0000e22b46d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x4c/0x80 fs/namei.c:1706
1 lock held by syz-executor397/4338:
1 lock held by syz-executor397/4342:
 #0: ffff0000e2374c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff0000e2374c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x4c/0x80 fs/namei.c:1706

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

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/16 11:33 linux-6.1.y 02b72ccb5f9d cfde8269 .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
2024/12/22 04:17 linux-6.1.y 29f02ec58a94 d7f584ee .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
2024/11/04 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
2025/02/26 15:47 linux-6.1.y 3a8358583626 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in d_alloc_parallel
2025/01/09 02:32 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in d_alloc_parallel
2025/01/01 19:10 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan 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
2024/12/23 03:47 linux-6.1.y 29f02ec58a94 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in d_alloc_parallel
2024/12/18 03:29 linux-6.1.y 52f863f820fd a0626d3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in d_alloc_parallel
* Struck through repros no longer work on HEAD.