syzbot


INFO: task hung in filemap_fault (7)

Status: auto-obsoleted due to no activity on 2025/11/26 06:06
Subsystems: net
[Documentation on labels]
First crash: 95d, last: 95d
Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in filemap_fault (3) mm 1 1 1456d 1456d 0/29 closed as invalid on 2022/02/08 09:40
upstream INFO: task hung in filemap_fault (5) mm fs 1 12 900d 1278d 0/29 auto-obsoleted due to no activity on 2023/09/13 22:48
linux-6.1 INFO: task hung in filemap_fault 1 2 914d 938d 0/3 auto-obsoleted due to no activity on 2023/09/09 11:34
linux-5.15 INFO: task hung in filemap_fault 1 1 833d 833d 0/3 auto-obsoleted due to no activity on 2023/11/29 22:47
upstream INFO: task hung in filemap_fault mm 1 24 2884d 2905d 0/29 closed as invalid on 2018/02/13 19:52
android-44 INFO: task hung in filemap_fault 1 3 2815d 2816d 0/2 auto-closed as invalid on 2019/02/22 14:09
upstream INFO: task hung in filemap_fault (6) mm 1 192 221d 510d 0/29 auto-obsoleted due to no activity on 2025/07/03 22:39
android-49 INFO: task hung in filemap_fault 1 4 2707d 2754d 0/3 auto-closed as invalid on 2019/02/22 14:49
upstream INFO: task hung in filemap_fault (2) mm 1 5 2597d 2802d 0/29 auto-closed as invalid on 2019/04/20 06:20
linux-5.15 INFO: task hung in filemap_fault (2) 1 1 462d 462d 0/3 auto-obsoleted due to no activity on 2024/12/04 10:30
upstream INFO: task hung in filemap_fault (4) mm 1 1 1374d 1374d 0/29 auto-closed as invalid on 2022/05/27 12:14

Sample crash report:
INFO: task syz.6.3451:19776 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.3451      state:D stack:24168 pid:19776 tgid:19774 ppid:13749  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 filemap_fault+0x86a/0x1200 mm/filemap.c:3452
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_read_fault mm/memory.c:5573 [inline]
 do_fault mm/memory.c:5707 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x3611/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:60
Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 8d 09 04 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08
RSP: 0018:ffffc9000adc7a18 EFLAGS: 00050206
RAX: 00007ffffffff001 RBX: 0000000000000038 RCX: 0000000000000038
RDX: 0000000000000001 RSI: 0000200000311000 RDI: ffffc9000adc7aa0
RBP: ffffc9000adc7c30 R08: ffffc9000adc7ad7 R09: 1ffff920015b8f5a
R10: dffffc0000000000 R11: fffff520015b8f5b R12: 0000000000000002
R13: dffffc0000000000 R14: ffffc9000adc7aa0 R15: 0000200000311000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
 _inline_copy_from_user include/linux/uaccess.h:178 [inline]
 _copy_from_user+0x7a/0xb0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 copy_msghdr_from_user net/socket.c:2544 [inline]
 recvmsg_copy_msghdr net/socket.c:2800 [inline]
 ___sys_recvmsg+0x12e/0x510 net/socket.c:2872
 do_recvmmsg+0x307/0x770 net/socket.c:2971
 __sys_recvmmsg net/socket.c:3045 [inline]
 __do_sys_recvmmsg net/socket.c:3068 [inline]
 __se_sys_recvmmsg net/socket.c:3061 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3061
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ee0d8ebe9
RSP: 002b:00007f8edeff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f8ee0fb6090 RCX: 00007f8ee0d8ebe9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f8ee0e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ee0fb6128 R14: 00007f8ee0fb6090 R15: 00007f8ee10dfa28
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:6/3174:
2 locks held by getty/5630:
 #0: ffff88814cf510a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:0/19752:
2 locks held by syz.6.3451/19776:
 #0: ffff88807cd74d20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:472 [inline]
 #0: ffff88807cd74d20 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:277 [inline]
 #0: ffff88807cd74d20 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:337
 #1: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #1: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_fault+0x86a/0x1200 mm/filemap.c:3452
2 locks held by syz.4.3462/19814:
4 locks held by kworker/1:5/20083:
 #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
 #1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
 #3: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
1 lock held by syz.9.3747/21350:
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.3747/21352:
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.3747/21354:
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.3747/21362:
 #0: ffff888148df63a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #0: ffff888148df63a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:901
1 lock held by syz.3.3765/21432:
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.3.3765/21435:
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888148df6548 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz-executor/21585:
2 locks held by dhcpcd-run-hook/21795:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
RIP: 0010:__sanitizer_cov_trace_switch+0x0/0x130 kernel/kcov.c:327
Code: 89 74 0a 18 48 89 44 0a 20 c3 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 06 48 8b 4e 08 48 83 c1 f8 48 c1 c1 3d 48 83 f9
RSP: 0018:ffffc90000ac6b48 EFLAGS: 00000297
RAX: 0000000000000005 RBX: 0000000000000000 RCX: 000000008b8b7e04
RDX: 0000000000000000 RSI: ffffffff8f8a8fb0 RDI: 0000000000000000
RBP: ffffffff8b8b7e6b R08: ffff88801e2b1e00 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000000 R12: ffffffff8b8b7e6c
R13: ffffc90000ac6bf8 R14: 0000000000000001 R15: ffffffff8b8b7e6b
FS:  0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555836f45c8 CR3: 0000000057c64000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 format_decode+0x84/0xe30 lib/vsprintf.c:2671
 vsnprintf+0x102/0xf00 lib/vsprintf.c:2869
 sprintf+0xd9/0x120 lib/vsprintf.c:3089
 print_time kernel/printk/printk.c:1381 [inline]
 info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407
 record_print_text+0x154/0x420 kernel/printk/printk.c:1456
 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024
 console_emit_next_record kernel/printk/printk.c:3092 [inline]
 console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
 __netdev_printk+0x3d7/0x4d0 net/core/dev.c:12598
 netdev_info+0x10a/0x160 net/core/dev.c:12653
 nsim_udp_tunnel_set_port+0x26e/0x3e0 drivers/net/netdevsim/udp_tunnels.c:31
 udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline]
 udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:249 [inline]
 __udp_tunnel_nic_device_sync+0xb0c/0x14d0 net/ipv4/udp_tunnel_nic.c:292
 udp_tunnel_nic_device_sync_work+0x97/0xa50 net/ipv4/udp_tunnel_nic.c:740
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/28 05:57 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in filemap_fault
* Struck through repros no longer work on HEAD.