syzbot


INFO: task hung in read_part_sector (3)

Status: upstream: reported on 2025/07/28 11:29
Reported-by: syzbot+910d3e8c08500bfcbc85@syzkaller.appspotmail.com
First crash: 22d, last: 22d
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in read_part_sector origin:upstream 1 C error 167 19h15m 752d 0/3 upstream: reported C repro on 2023/07/29 13:11
linux-6.1 INFO: task hung in read_part_sector 1 1 560d 560d 0/3 auto-obsoleted due to no activity on 2024/05/17 07:34
upstream INFO: task hung in read_part_sector block 1 2 576d 642d 0/29 auto-obsoleted due to no activity on 2024/04/21 10:47
linux-6.6 INFO: task hung in read_part_sector 1 23 6d18h 61d 0/2 upstream: reported on 2025/06/19 22:23
linux-6.1 INFO: task hung in read_part_sector (2) 1 1 438d 438d 0/3 auto-obsoleted due to no activity on 2024/09/16 08:59
upstream INFO: task hung in read_part_sector (2) block 1 2092 40m 380d 0/29 upstream: reported on 2024/08/04 19:22

Sample crash report:
INFO: task udevd:4439 blocked for more than 143 seconds.
      Not tainted 6.1.147-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:23040 pid:4439  ppid:3637   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797
 folio_wait_bit_common+0x6e1/0xf60 mm/filemap.c:1324
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x1a9/0x760 mm/filemap.c:3609
 read_mapping_folio include/linux/pagemap.h:797 [inline]
 read_part_sector+0xce/0x350 block/partitions/core.c:724
 adfspart_check_POWERTEC+0xb4/0x870 block/partitions/acorn.c:454
 check_partition block/partitions/core.c:146 [inline]
 blk_add_partitions block/partitions/core.c:609 [inline]
 bdev_disk_changed+0x7bd/0x1480 block/partitions/core.c:695
 blkdev_get_whole+0x2e8/0x370 block/bdev.c:687
 blkdev_get_by_dev+0x32e/0xa60 block/bdev.c:824
 blkdev_open+0x11e/0x2e0 block/fops.c:500
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3626 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3783
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
 do_sys_openat2+0x142/0x490 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]
 __x64_sys_openat+0x135/0x160 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5ea38a7407
RSP: 002b:00007ffe7c9fc3c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5ea3f71880 RCX: 00007f5ea38a7407
RDX: 00000000000a0800 RSI: 000056387b9e41c0 RDI: ffffffffffffff9c
RBP: 000056387b9c9910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056387b9fa1f0
R13: 000056387b9e1420 R14: 0000000000000000 R15: 000056387b9fa1f0
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2b7b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2bfd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4033:
 #0: ffff888030377098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by udevd/4439:
 #0: ffff888024db24c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:815
3 locks held by kworker/u4:17/4752:
 #0: ffff8880b8e3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0xf9/0x420 kernel/trace/bpf_trace.c:2326
 #2: ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
2 locks held by dhcpcd-run-hook/12107:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12111 Comm: dhcpcd-run-hook Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:unwind_next_frame+0x3f3/0x20b0 arch/x86/kernel/unwind_orc.c:461
Code: 28 84 c0 0f 85 39 17 00 00 41 c6 06 01 49 c7 c4 c0 79 89 8a 49 8d 6c 24 04 4d 8d 7c 24 05 48 89 e8 48 c1 e8 03 48 89 44 24 48 <42> 0f b6 04 28 84 c0 0f 85 72 16 00 00 4c 89 f8 48 c1 e8 03 42 0f
RSP: 0018:ffffc90005b17230 EFLAGS: 00000a03
RAX: 1ffffffff1d52cf4 RBX: ffffc90005b17308 RCX: ffffffff8e361e90
RDX: ffffffff8ea96784 RSI: ffffffff8e361e74 RDI: ffffffff8138551f
RBP: ffffffff8ea967a6 R08: 0000000000000011 R09: 0000000000000000
R10: fffff52000b62e6d R11: 1ffff92000b62e6b R12: ffffffff8ea967a2
R13: dffffc0000000000 R14: ffffffff8e361e8c R15: ffffffff8ea967a7
FS:  00007f8d3c3a8c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d3c60c7e8 CR3: 000000006b732000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422
 anon_vma_chain_alloc mm/rmap.c:141 [inline]
 anon_vma_clone+0xb4/0x4e0 mm/rmap.c:287
 anon_vma_fork+0x75/0x4f0 mm/rmap.c:350
 dup_mmap kernel/fork.c:663 [inline]
 dup_mm kernel/fork.c:1541 [inline]
 copy_mm+0xb44/0x15c0 kernel/fork.c:1590
 copy_process+0x1953/0x4020 kernel/fork.c:2351
 kernel_clone+0x225/0x8b0 kernel/fork.c:2757
 __do_sys_clone kernel/fork.c:2898 [inline]
 __se_sys_clone kernel/fork.c:2882 [inline]
 __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8d3c542636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffcc62a3160 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffcc62a3168 RCX: 00007f8d3c542636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000055d977efbe60 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f8d3c3a8f50 R11: 0000000000000246 R12: 000055d977efe060
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/28 11:29 linux-6.1.y 3594f306da12 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in read_part_sector
* Struck through repros no longer work on HEAD.