syzbot


INFO: task hung in anon_pipe_read (2)

Status: auto-obsoleted due to no activity on 2025/12/22 10:52
Subsystems: fs
[Documentation on labels]
First crash: 138d, last: 138d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in anon_pipe_read fs 1 5 268d 268d 0/29 auto-obsoleted due to no activity on 2025/08/14 11:31

Sample crash report:
INFO: task syz-executor:6516 blocked for more than 143 seconds.
      Not tainted syz
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:6516  tgid:6516  ppid:6515   task_flags:0x400100 flags:0x00000008
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7115
 __mutex_lock_common+0xd04/0x2678 kernel/locking/mutex.c:676
 __mutex_lock kernel/locking/mutex.c:760 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
 anon_pipe_read+0x10c/0xcc0 fs/pipe.c:282
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x670/0x93c fs/read_write.c:572
 ksys_read+0x120/0x210 fs/read_write.c:715
 __do_sys_read fs/read_write.c:724 [inline]
 __se_sys_read fs/read_write.c:722 [inline]
 __arm64_sys_read+0x7c/0x90 fs/read_write.c:722
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
INFO: task syz.2.55:6931 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.55        state:D stack:0     pid:6931  tgid:6930  ppid:6535   task_flags:0x400140 flags:0x00000011
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 io_schedule+0x84/0xf0 kernel/sched/core.c:7903
 folio_wait_bit_common+0x56c/0x9e0 mm/filemap.c:1317
 __folio_lock+0x2c/0x3c mm/filemap.c:1675
 folio_lock include/linux/pagemap.h:1133 [inline]
 invalidate_inode_pages2_range+0x488/0xa9c mm/truncate.c:690
 bch2_write_invalidate_inode_pages_range+0xc4/0x12c fs/bcachefs/fs-io-pagecache.c:68
 bch2_direct_write+0x1fe0/0x2280 fs/bcachefs/fs-io-direct.c:662
 bch2_write_iter+0x16c/0x2300 fs/bcachefs/fs-io-buffered.c:1064
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x540/0xa3c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
INFO: task syz.2.55:6994 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.55        state:D stack:0     pid:6994  tgid:6930  ppid:6535   task_flags:0x440040 flags:0x00000019
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 __bch2_two_state_lock+0x1b4/0x2f0 fs/bcachefs/two_state_shared_lock.c:7
 bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:55 [inline]
 bch2_readahead+0xbc8/0xd88 fs/bcachefs/fs-io-buffered.c:296
 read_pages+0x13c/0x4c4 mm/readahead.c:160
 page_cache_ra_order+0x7a0/0xb7c mm/readahead.c:512
 page_cache_sync_ra+0x580/0x73c mm/readahead.c:619
 filemap_get_pages+0x2f4/0x19c8 mm/filemap.c:2603
 filemap_splice_read+0x454/0xad8 mm/filemap.c:2991
 do_splice_read fs/splice.c:982 [inline]
 splice_file_to_pipe+0x374/0x5a8 fs/splice.c:1292
 do_sendfile+0x37c/0x658 fs/read_write.c:1376
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __arm64_sys_sendfile64+0x1b4/0x274 fs/read_write.c:1417
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
1 lock held by khungtaskd/32:
 #0: ffff80008f9d9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
2 locks held by pr/ttyAMA-1/43:
2 locks held by getty/6313:
 #0: ffff0000d7bd80a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff800099e8e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/6516:
 #0: ffff0000d9781c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_read+0x10c/0xcc0 fs/pipe.c:282
2 locks held by syz.2.55/6931:
 #0: ffff0000d7ac3278 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x1fc/0x2a0 fs/file.c:1232
 #1: ffff0000cd7fa428 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
 #1: ffff0000cd7fa428 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x24c/0xa3c fs/read_write.c:682
2 locks held by syz.2.55/6994:
 #0: ffff0000d9781c68 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x68/0x98 fs/pipe.c:91
 #1: ffff0000f6f802e8 (mapping.invalidate_lock#6){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:935 [inline]
 #1: ffff0000f6f802e8 (mapping.invalidate_lock#6){.+.+}-{4:4}, at: page_cache_ra_order+0x268/0xb7c mm/readahead.c:488

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/23 10:50 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b5db4add5e77 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in anon_pipe_read
* Struck through repros no longer work on HEAD.