Hello, syzbot found the following issue on: HEAD commit: 36a21d51725a Linux 5.14-rc5 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=104b8eaa300000 kernel config: https://syzkaller.appspot.com/x/.config?x=e3a20bae04b96ccd dashboard link: https://syzkaller.appspot.com/bug?extid=bea44a5189836d956894 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=143c0ee9300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=158fc9aa300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bea44a5189836d956894@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor276:8433 blocked for more than 143 seconds. Not tainted 5.14.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor276 state:D stack:27736 pid: 8433 ppid: 8430 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 fuse_wait_on_page_writeback fs/fuse/file.c:452 [inline] fuse_wait_on_page_writeback+0x120/0x170 fs/fuse/file.c:448 fuse_launder_page fs/fuse/file.c:2316 [inline] fuse_launder_page+0xe9/0x130 fs/fuse/file.c:2306 do_launder_page mm/truncate.c:595 [inline] invalidate_inode_pages2_range+0x994/0xf80 mm/truncate.c:661 fuse_finish_open+0x2d9/0x560 fs/fuse/file.c:202 fuse_open_common+0x2f9/0x4c0 fs/fuse/file.c:254 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_creat fs/open.c:1294 [inline] __se_sys_creat fs/open.c:1288 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1288 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x446409 RSP: 002b:00007f0e6a9f92f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00000000004d34f0 RCX: 0000000000446409 RDX: 0000000000446409 RSI: 0000000000000000 RDI: 0000000020000280 RBP: 00000000004a3164 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 000000000049f158 R14: 00000000004a1160 R15: 00000000004d34f8 Showing all locks held in the system: 1 lock held by khungtaskd/1584: #0: ffffffff8b97c1c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 2 locks held by syz-executor276/8433: #0: ffff888015e38460 (sb_writers#11){.+.+}-{0:0}, at: do_open fs/namei.c:3367 [inline] #0: ffff888015e38460 (sb_writers#11){.+.+}-{0:0}, at: path_openat+0x1aee/0x27f0 fs/namei.c:3507 #1: ffff8880397d0150 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #1: ffff8880397d0150 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: fuse_open_common+0x366/0x4c0 fs/fuse/file.c:241 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1584 Comm: khungtaskd Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xd0a/0xfc0 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:553 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
