syzbot


INFO: task hung in hugetlb_fault

Status: upstream: reported on 2024/09/09 10:06
Reported-by: syzbot+82c907906c520848e4a2@syzkaller.appspotmail.com
First crash: 65d, last: 65d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in hugetlb_fault 1 1406d 1406d 0/1 auto-closed as invalid on 2021/05/07 13:07
upstream INFO: task hung in hugetlb_fault mm C done 65 16d 67d 0/28 upstream: reported C repro on 2024/09/07 06:23

Sample crash report:
INFO: task syz.1.4211:15230 blocked for more than 143 seconds.
      Not tainted 6.1.109-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4211      state:D stack:25832 pid:15230 ppid:13976  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 io_schedule+0x88/0x100 kernel/sched/core.c:8786
 folio_wait_bit_common+0x878/0x1290 mm/filemap.c:1296
 __filemap_get_folio+0x47c/0xe80 mm/filemap.c:1931
 pagecache_get_page+0x28/0x250 mm/folio-compat.c:110
 find_lock_page include/linux/pagemap.h:621 [inline]
 hugetlb_fault+0x92f/0x2c50 mm/hugetlb.c:6162
 handle_mm_fault+0x3218/0x5340 mm/memory.c:5273
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f622374497c
RSP: 002b:00007ffcce765ee8 EFLAGS: 00010246
RAX: 0000000020000d00 RBX: 0000000000000004 RCX: 8000000000000010
RDX: 0000000000000010 RSI: 00007f62230005d6 RDI: 0000000020000d00
RBP: 00007f6223937a80 R08: 00007f6223400000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00000000000b3737
R13: 00007ffcce765ff0 R14: 0000000000000032 R15: fffffffffffffffe
 </TASK>
INFO: task syz.1.4211:15231 blocked for more than 143 seconds.
      Not tainted 6.1.109-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4211      state:D stack:25984 pid:15231 ppid:13976  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 hugetlb_wp+0x11f0/0x3090 mm/hugetlb.c:5655
 hugetlb_fault+0x13a4/0x2c50 mm/hugetlb.c:6207
 handle_mm_fault+0x3218/0x5340 mm/memory.c:5273
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166
Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 <f3> a4 31 c0 0f 01 ca c3 89 ca eb 0a 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc9000b59fa90 EFLAGS: 00050246
RAX: ffffffff84396801 RBX: 00007fffffffefc0 RCX: 0000000000000040
RDX: 0000000000000040 RSI: ffffc9000b59fb20 RDI: 000000002000f2c0
RBP: ffffc9000b59fbd0 R08: dffffc0000000000 R09: fffff520016b3f6c
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000040
R13: 000000000000ec80 R14: 000000002000f2c0 R15: ffffc9000b59fb20
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 _copy_to_user+0xe9/0x130 lib/usercopy.c:41
 copy_to_user include/linux/uaccess.h:169 [inline]
 rng_dev_read+0x39b/0x6b0 drivers/char/hw_random/core.c:267
 do_iter_read+0x500/0xc80 fs/read_write.c:798
 vfs_readv fs/read_write.c:916 [inline]
 do_preadv+0x20e/0x350 fs/read_write.c:1008
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f622377cef9
RSP: 002b:00007f622458f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f6223935f80 RCX: 00007f622377cef9
RDX: 0000000000000002 RSI: 0000000020000580 RDI: 0000000000000005
RBP: 00007f62237ef046 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6223935f80 R15: 00007ffcce765d88
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b190 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b990 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by kworker/u4:2/33:
 #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000a9fd20 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffc90000a9fd20 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffc90000a9fd20 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: newidle_balance+0x2c9/0x10b0 kernel/sched/fair.c:11579
2 locks held by getty/3398:
 #0: ffff88814b90c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
3 locks held by kworker/u4:5/3669:
 #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545
 #1: ffff8880b8f27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:1001
 #2: ffff88807a898d40 (&wdev->mtx){+.+.}-{3:3}, at: sdata_lock net/mac80211/ieee80211_i.h:1113 [inline]
 #2: ffff88807a898d40 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_ibss_work+0xa0/0x1480 net/mac80211/ibss.c:1680
3 locks held by syz.1.4211/15230:
 #0: ffff88807e059058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
 #1: ffff88801d2703c8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_fault+0x63e/0x2c50 mm/hugetlb.c:6105
 #2: ffff888026e428e8 (&resv_map->rw_sema){++++}-{3:3}, at: hugetlb_fault+0x6cd/0x2c50 mm/hugetlb.c:6116
2 locks held by syz.1.4211/15231:
 #0: ffff88807e059058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
 #1: ffff88801d2703c8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_wp+0x11f0/0x3090 mm/hugetlb.c:5655
2 locks held by syz.1.4412/16001:
 #0: ffff888055d7e2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
 #1: ffff88801d2703c8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_fault+0x63e/0x2c50 mm/hugetlb.c:6105
1 lock held by syz.1.4642/16771:
 #0: ffffffff8d330480 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4019

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.109-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 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+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7585 Comm: kworker/1:15 Not tainted 6.1.109-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:check_preemption_disabled+0x5c/0x110 lib/smp_processor_id.c:19
Code: 25 28 00 00 00 48 3b 44 24 08 0f 85 c7 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c9 49 89 f6 49 89 ff 65 4c 8b 25 1d ab 5b
RSP: 0018:ffffc9000310fa60 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffff88802cf19dc0
RDX: 0000000000000000 RSI: ffffffff8b0c0f40 RDI: ffffffff8b5d69c0
RBP: 00000000ffffffff R08: dffffc0000000000 R09: fffffbfff1b9ff45
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246
R13: ffff88802cf19dc0 R14: 00000000ffffffff R15: ffffffff8d32b020
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f959c0fc178 CR3: 000000001e3fe000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
 lock_is_held_type+0x76/0x180 kernel/locking/lockdep.c:5704
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0xa1/0x780 kernel/sched/core.c:9917
 wg_ratelimiter_gc_entries+0x3c9/0x470 drivers/net/wireguard/ratelimiter.c:78
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/09 10:05 linux-6.1.y 5ca5b389fddf 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in hugetlb_fault
* Struck through repros no longer work on HEAD.