syzbot


INFO: task hung in __fdget_pos (3)

Status: upstream: reported on 2024/08/11 10:43
Reported-by: syzbot+4fb0eae4a6e28994ac02@syzkaller.appspotmail.com
First crash: 65d, last: 8h03m
Similar bugs (12)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in __fdget_pos (2) 5 31d 65d 0/3 upstream: reported on 2024/08/11 21:32
upstream INFO: task hung in __fdget_pos kernfs 1 2395d 2395d 0/28 closed as invalid on 2018/03/27 11:08
android-44 INFO: task hung in __fdget_pos 2 2215d 2228d 0/2 auto-closed as invalid on 2019/03/21 05:21
linux-6.1 INFO: task hung in __fdget_pos 1 373d 373d 0/3 auto-obsoleted due to no activity on 2024/01/16 13:13
android-49 INFO: task hung in __fdget_pos 22 2216d 2347d 0/3 auto-closed as invalid on 2019/03/20 03:41
upstream INFO: task hung in __fdget_pos (4) fs C error 297 15d 408d 0/28 upstream: reported C repro on 2023/09/03 04:11
upstream INFO: task hung in __fdget_pos (3) fs 3 1102d 1119d 0/28 auto-closed as invalid on 2022/01/07 10:38
android-414 INFO: task hung in __fdget_pos 1 2084d 2015d 0/1 auto-closed as invalid on 2019/07/30 11:39
linux-5.15 INFO: task hung in __fdget_pos (2) 2 172d 184d 0/3 auto-obsoleted due to no activity on 2024/08/04 06:39
linux-5.15 INFO: task hung in __fdget_pos 1 564d 564d 0/3 auto-obsoleted due to no activity on 2023/07/29 10:54
upstream INFO: task hung in __fdget_pos (2) fs 36 2107d 2332d 0/28 closed as dup on 2018/10/27 13:29
upstream INFO: task can't die in __fdget_pos fs 1 977d 977d 0/28 auto-closed as invalid on 2022/04/12 09:48

Sample crash report:
INFO: task syz.0.89:4400 blocked for more than 142 seconds.
      Not tainted 5.15.164-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.89        state:D stack:28512 pid: 4400 ppid:  3570 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 __fdget_pos+0x2cb/0x380 fs/file.c:1088
 fdget_pos include/linux/file.h:75 [inline]
 ksys_read+0x7e/0x2c0 fs/read_write.c:614
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7faa5b6109f9
RSP: 002b:00007faa59a6e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007faa5b79f058 RCX: 00007faa5b6109f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007faa5b67e8ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007faa5b79f058 R15: 00007fff86579998
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3321:
 #0: ffff888024072098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000209b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:11/3665:
 #0: ffff8880b9b3a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9b27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x53d/0x810 kernel/sched/psi.c:891
3 locks held by syz.2.40/3810:
2 locks held by syz.0.89/4394:
1 lock held by syz.0.89/4400:
 #0: ffff88801b22d9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1088
2 locks held by syz.1.124/4569:
1 lock held by syz.1.124/4570:
 #0: ffff8880790a8ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1088
3 locks held by syz.3.159/4764:
1 lock held by syz.4.451/6343:
2 locks held by syz.1.452/6351:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: phy10 ieee80211_iface_work
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x74/0x290 mm/kasan/generic.c:189
Code: 49 c1 ea 03 49 bb 01 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 <49> 01 da 41 80 39 00 0f 85 c4 01 00 00 49 ff c1 49 ff c2 75 ee e9
RSP: 0018:ffffc90002047580 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff92000408eda RCX: ffffffff813893b8
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900020476d0
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffff52000408eda
R10: e00006dfffbf7124 R11: dffffc0000000001 R12: 1ffffffff1cd47e8
R13: 1ffffffff1cd47e8 R14: fffff52000408edc R15: ffffc90002047680
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fae392cc178 CR3: 000000006589b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 memset+0x1f/0x40 mm/kasan/shadow.c:44
 unwind_next_frame+0xbc8/0x1fa0 arch/x86/kernel/unwind_orc.c:547
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0xf1/0x270 mm/slub.c:4559
 skb_free_head net/core/skbuff.c:655 [inline]
 skb_release_data+0x73a/0x8a0 net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb_reason+0xb3/0x170 net/core/skbuff.c:776
 kfree_skb include/linux/skbuff.h:1123 [inline]
 ieee80211_iface_work+0x251/0xcc0 net/mac80211/iface.c:1497
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (39):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/11 11:15 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __fdget_pos
2024/08/11 11:14 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __fdget_pos
2024/08/11 11:12 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __fdget_pos
2024/10/15 15:23 linux-5.15.y 3a5928702e71 7eb57b4a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/15 15:22 linux-5.15.y 3a5928702e71 7eb57b4a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/12 03:00 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/12 02:59 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/08 10:14 linux-5.15.y 3a5928702e71 402f1df0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/04 03:03 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/03 21:06 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/10/01 08:20 linux-5.15.y 3a5928702e71 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/30 05:21 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/28 16:17 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/27 12:33 linux-5.15.y 3a5928702e71 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/25 05:13 linux-5.15.y 3a5928702e71 5643e0e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/24 20:44 linux-5.15.y 3a5928702e71 5643e0e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/23 21:31 linux-5.15.y 3a5928702e71 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/21 04:56 linux-5.15.y 3a5928702e71 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/13 20:05 linux-5.15.y 3a5928702e71 b58f933c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/09 08:03 linux-5.15.y 14e468424d3e 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/05 14:42 linux-5.15.y 14e468424d3e 464ac2ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/02 17:03 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/02 15:40 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/09/01 19:05 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/30 22:34 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/30 22:34 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/30 22:33 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/27 21:50 linux-5.15.y fa93fa65db6e 6c853ff9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/27 21:47 linux-5.15.y fa93fa65db6e 6c853ff9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/26 05:47 linux-5.15.y fa93fa65db6e d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/24 08:49 linux-5.15.y fa93fa65db6e d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/14 20:35 linux-5.15.y 7e89efd3ae1c e6b88e20 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/14 20:33 linux-5.15.y 7e89efd3ae1c e6b88e20 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/12 11:33 linux-5.15.y 7e89efd3ae1c 842184b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/11 11:40 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/11 10:59 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/11 10:54 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/11 10:49 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
2024/08/11 10:42 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in __fdget_pos
* Struck through repros no longer work on HEAD.