syzbot


INFO: task hung in exfat_sync_fs

Status: upstream: reported on 2023/10/27 20:30
Reported-by: syzbot+0d1cb0a990ed164d3874@syzkaller.appspotmail.com
First crash: 235d, last: 4d18h
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in exfat_sync_fs exfat 1304 1h32m 325d 0/27 upstream: reported on 2023/07/29 17:40
linux-5.15 INFO: task hung in exfat_sync_fs 3 219d 315d 0/3 auto-obsoleted due to no activity on 2024/02/20 04:29
linux-5.15 INFO: task hung in exfat_sync_fs (2) 6 8d10h 43d 0/3 upstream: reported on 2024/05/06 19:33

Sample crash report:
INFO: task syz-executor.3:9349 blocked for more than 143 seconds.
      Not tainted 6.1.90-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:23992 pid:9349  ppid:6864   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 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
 exfat_sync_fs+0x67/0x100 fs/exfat/super.c:65
 iterate_supers+0x127/0x1e0 fs/super.c:746
 ksys_sync+0xd7/0x1c0 fs/sync.c:104
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 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: 0033:0x7f7d37c7dd69
RSP: 002b:00007f7d389920c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f7d37dabf80 RCX: 00007f7d37c7dd69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f7d37cca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7d37dabf80 R15: 00007ffd5fa67a88
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12ae50 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b650 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by kworker/0:2/152:
 #0: ffff888012472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90002ddfd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
2 locks held by getty/3305:
 #0: ffff888028f0a098 (&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:2188
2 locks held by kworker/u4:7/4112:
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900031dfd20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
3 locks held by syz-executor.0/5148:
2 locks held by syz-executor.3/9349:
 #0: ffff88807a4340e0 (&type->s_umount_key#71){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744
 #1: ffff888073ac60e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:65
1 lock held by syz-executor.3/10799:
 #0: ffffffff8d130278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #0: ffffffff8d130278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
4 locks held by syz-executor.4/11204:
3 locks held by syz-executor.1/11206:
 #0: ffffffff8e2f9ab0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860
 #1: ffff88806288b2f8 (&devlink->lock_key#25){+.+.}-{3:3}, at: devl_lock net/devlink/leftover.c:275 [inline]
 #1: ffff88806288b2f8 (&devlink->lock_key#25){+.+.}-{3:3}, at: devlink_nl_pre_doit+0x96/0xa50 net/devlink/leftover.c:783
 #2: ffffffff8d130140 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4018
2 locks held by syz-executor.2/11241:
1 lock held by syz-executor.0/11224:
 #0: ffff888072c45010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #0: ffff888072c45010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
 #0: ffff888072c45010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x98/0x230 net/socket.c:1400

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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+0x1b0/0x3f0 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:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11225 Comm: syz-executor.0 Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [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+0x81/0x290 mm/kasan/generic.c:189
Code: 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 1d 01 00 00 45 89 cf 41 83 e7 07 0f 84
RSP: 0018:ffffc90005757218 EFLAGS: 00000246
RAX: ffffffff81bc1d01 RBX: 1ffffd4000380630 RCX: ffffffff81bc1dd2
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001c03180
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffff94000380630
R10: ffffffffffffffff R11: dffffc0000000001 R12: 1ffffd4000380630
R13: ffff8880772741e8 R14: fffff94000380631 R15: ffffea0001c03188
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000a038 CR3: 000000007384f000 CR4: 00000000003526f0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 folio_test_unevictable include/linux/page-flags.h:558 [inline]
 folio_inc_refs mm/swap.c:436 [inline]
 folio_mark_accessed+0x122/0x1c90 mm/swap.c:478
 zap_pte_range mm/memory.c:1450 [inline]
 zap_pmd_range mm/memory.c:1574 [inline]
 zap_pud_range mm/memory.c:1603 [inline]
 zap_p4d_range mm/memory.c:1624 [inline]
 unmap_page_range+0x1143/0x2740 mm/memory.c:1645
 unmap_vmas+0x48b/0x640 mm/memory.c:1730
 exit_mmap+0x252/0x9f0 mm/mmap.c:3227
 __mmput+0x115/0x3c0 kernel/fork.c:1199
 exit_mm+0x226/0x300 kernel/exit.c:563
 do_exit+0x9f6/0x26a0 kernel/exit.c:856
 do_group_exit+0x202/0x2b0 kernel/exit.c:1019
 get_signal+0x16f7/0x17d0 kernel/signal.c:2862
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fde7147dd69
Code: Unable to access opcode bytes at 0x7fde7147dd3f.
RSP: 002b:00007fde7226a178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fde715abf88 RCX: 00007fde7147dd69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fde715abf88
RBP: 00007fde715abf80 R08: 00007fde7226a6c0 R09: 00007fde7226a6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde715abf8c
R13: 000000000000000b R14: 00007fff1e1bc5e0 R15: 00007fff1e1bc6c8
 </TASK>

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/13 21:58 linux-6.1.y 909ba1f1b414 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/03/01 15:02 linux-6.1.y a3eb3a74aa8c 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/28 14:02 linux-6.1.y 81e1dc2f7001 55d6f11d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/27 20:10 linux-6.1.y 81e1dc2f7001 d367cbe5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/23 19:37 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/23 13:58 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/22 00:06 linux-6.1.y 8b4118fabd6e 345111b5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/20 04:29 linux-6.1.y 8b4118fabd6e 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/02/19 16:08 linux-6.1.y 8b4118fabd6e 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2023/11/22 18:58 linux-6.1.y 69e434a1cb21 03e12510 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2023/11/20 19:51 linux-6.1.y 69e434a1cb21 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2023/11/13 22:26 linux-6.1.y fb2635ac69ab cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2023/11/12 04:22 linux-6.1.y fb2635ac69ab 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2023/10/27 22:36 linux-6.1.y 32c9cdbe383c 3c418d72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in exfat_sync_fs
2024/06/14 09:23 linux-6.1.y ae9f2a70d69e 8d849073 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in exfat_sync_fs
2024/06/14 09:22 linux-6.1.y ae9f2a70d69e 8d849073 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in exfat_sync_fs
2024/05/08 14:06 linux-6.1.y 909ba1f1b414 4cf3f9b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in exfat_sync_fs
2023/10/27 20:29 linux-6.1.y 32c9cdbe383c 3c418d72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in exfat_sync_fs
* Struck through repros no longer work on HEAD.