Message-ID: <67171113.050a0220.1e4b4d.006c.GAE@google.com>
Date: Mon, 21 Oct 2024 19:42:27 -0700
From: syzbot <syzbot+0dbb0d6fda088e78a4d8@...kaller.appspotmail.com>
To: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, 
	miklos@...redi.hu, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [fuse?] INFO: task hung in __fuse_simple_request

Hello,

syzbot found the following issue on:

HEAD commit:    715ca9dd687f Merge tag 'io_uring-6.12-20241019' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f6ca40580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=16e543edc81a3008
dashboard link: https://syzkaller.appspot.com/bug?extid=0dbb0d6fda088e78a4d8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1478a0a7980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-715ca9dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba436e2363b6/vmlinux-715ca9dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3ac78a7a1a30/bzImage-715ca9dd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0dbb0d6fda088e78a4d8@...kaller.appspotmail.com

INFO: task syz.1.16:5435 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.16        state:D stack:26736 pid:5435  tgid:5429  ppid:5222   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 request_wait_answer fs/fuse/dev.c:464 [inline]
 __fuse_request_send fs/fuse/dev.c:478 [inline]
 __fuse_simple_request+0xe17/0x1840 fs/fuse/dev.c:572
 fuse_simple_request fs/fuse/fuse_i.h:1156 [inline]
 fuse_send_open fs/fuse/file.c:51 [inline]
 fuse_file_open+0x599/0xb40 fs/fuse/file.c:146
 fuse_do_open fs/fuse/file.c:175 [inline]
 fuse_open+0x341/0x720 fs/fuse/file.c:264
 do_dentry_open+0x978/0x1460 fs/open.c:958
 vfs_open+0x3e/0x330 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x2c84/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff76397dff9
RSP: 002b:00007ff764752038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff763b36058 RCX: 00007ff76397dff9
RDX: 0000000000101001 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 00007ff7639f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ff763b36058 R15: 00007ffe4de011e8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/25:
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
1 lock held by klogd/4585:
 #0: ffff88801fc3ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593
2 locks held by getty/4894:
 #0: ffff88801e1690a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000039b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz-execprog/5119:
1 lock held by syz-executor/5120:
1 lock held by dhcpcd-run-hook/5428:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 25 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>


---
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