Hello, syzbot found the following issue on: HEAD commit: 274a2eebf80c Merge tag 'for_linus' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=110b183d080000 kernel config: https://syzkaller.appspot.com/x/.config?x=3b9175e0879a7749 dashboard link: https://syzkaller.appspot.com/bug?extid=8fba0e0286621ce71edd compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13db992d080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1301c1f3080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8fba0e0286621ce71edd@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syslogd:2954 blocked for more than 143 seconds. Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syslogd state:D stack:25896 pid: 2954 ppid: 1 flags:0x00000000 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 rwsem_down_read_slowpath+0x59f/0xb10 kernel/locking/rwsem.c:1087 __down_read_common kernel/locking/rwsem.c:1252 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xe2/0x450 kernel/locking/rwsem.c:1501 inode_lock_shared include/linux/fs.h:766 [inline] lookup_slow fs/namei.c:1701 [inline] walk_component+0x332/0x5a0 fs/namei.c:1993 link_path_walk.part.0+0x74e/0xe20 fs/namei.c:2320 link_path_walk fs/namei.c:2245 [inline] path_openat+0x262/0x28f0 fs/namei.c:3687 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1311 do_sys_open fs/open.c:1327 [inline] __do_sys_openat fs/open.c:1343 [inline] __se_sys_openat fs/open.c:1338 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1338 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+0x63/0xcd RIP: 0033:0x7f600686b697 RSP: 002b:00007ffc893ed6a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055f27b512910 RCX: 00007f600686b697 RDX: 0000000000000d41 RSI: 00007f60069f999a RDI: 00000000ffffff9c RBP: 00007f60069f999a R08: 00007f60068fb040 R09: 00007f60068fb0c0 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000d41 R13: 000055f27b512a50 R14: 0000000000000003 R15: 000055f27b512a60 </TASK> INFO: task udevd:2972 blocked for more than 143 seconds. Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:27096 pid: 2972 ppid: 1 flags:0x00000000 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 rwsem_down_read_slowpath+0x59f/0xb10 kernel/locking/rwsem.c:1087 __down_read_common kernel/locking/rwsem.c:1252 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xe2/0x450 kernel/locking/rwsem.c:1501 inode_lock_shared include/linux/fs.h:766 [inline] lookup_slow fs/namei.c:1701 [inline] walk_component+0x332/0x5a0 fs/namei.c:1993 link_path_walk.part.0+0x74e/0xe20 fs/namei.c:2320 link_path_walk fs/namei.c:2244 [inline] path_lookupat+0xb7/0x840 fs/namei.c:2473 filename_lookup+0x1ce/0x590 fs/namei.c:2503 vfs_statx+0x148/0x390 fs/stat.c:228 vfs_fstatat+0x8c/0xb0 fs/stat.c:255 __do_sys_newfstatat+0x91/0x110 fs/stat.c:425 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+0x63/0xcd RIP: 0033:0x7f93c7f7a1da RSP: 002b:00007fffc0378198 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000555918b966a0 RCX: 00007f93c7f7a1da RDX: 00007fffc03781a8 RSI: 0000555918b847ed RDI: 00000000ffffff9c RBP: 0000555918e507b8 R08: 0000000002a8adc5 R09: 00007fffc03c7080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 00007fffc03781a8 </TASK> INFO: task syz-executor412:3612 blocked for more than 143 seconds. Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor412 state:D stack:26448 pid: 3612 ppid: 3609 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 rwsem_down_read_slowpath+0x59f/0xb10 kernel/locking/rwsem.c:1087 __down_read_common kernel/locking/rwsem.c:1252 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xe2/0x450 kernel/locking/rwsem.c:1501 inode_lock_shared include/linux/fs.h:766 [inline] lookup_slow fs/namei.c:1701 [inline] walk_component+0x332/0x5a0 fs/namei.c:1993 link_path_walk.part.0+0x74e/0xe20 fs/namei.c:2320 link_path_walk fs/namei.c:2245 [inline] path_openat+0x262/0x28f0 fs/namei.c:3687 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1311 do_sys_open fs/open.c:1327 [inline] __do_sys_openat fs/open.c:1343 [inline] __se_sys_openat fs/open.c:1338 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1338 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+0x63/0xcd RIP: 0033:0x7f29b1af0238 RSP: 002b:00007ffea611c300 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f29b1af0238 RDX: 0000000000090800 RSI: 00007f29b1b46060 RDI: 00000000ffffff9c RBP: 0000000000000e1d R08: 0000000000090800 R09: 00007f29b1b46060 R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffea611c394 R13: 00007ffea611c3f0 R14: 0000000000000000 R15: 431bde82d7b634db </TASK> INFO: task syz-executor412:3614 blocked for more than 144 seconds. Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor412 state:D stack:26960 pid: 3614 ppid: 3612 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 request_wait_answer+0x46d/0x850 fs/fuse/dev.c:407 __fuse_request_send fs/fuse/dev.c:426 [inline] fuse_simple_request+0x71d/0xe50 fs/fuse/dev.c:511 fuse_lookup_name+0x280/0x630 fs/fuse/dir.c:392 fuse_lookup.part.0+0xdf/0x390 fs/fuse/dir.c:433 fuse_lookup+0x70/0x90 fs/fuse/dir.c:429 __lookup_slow+0x24c/0x460 fs/namei.c:1685 lookup_slow fs/namei.c:1702 [inline] walk_component+0x33f/0x5a0 fs/namei.c:1993 link_path_walk.part.0+0x74e/0xe20 fs/namei.c:2320 link_path_walk fs/namei.c:2245 [inline] path_openat+0x262/0x28f0 fs/namei.c:3687 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1311 do_sys_open fs/open.c:1327 [inline] __do_sys_openat fs/open.c:1343 [inline] __se_sys_openat fs/open.c:1338 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1338 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+0x63/0xcd RIP: 0033:0x7f29b1af05b9 RSP: 002b:00007f29b1aa12f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f29b1b7b4c0 RCX: 00007f29b1af05b9 RDX: 0000000000000042 RSI: 0000000020002080 RDI: ffffffffffffff9c RBP: 00007f29b1b48084 R08: 0000000000000065 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000065 R13: 00007f29b1b480a8 R14: 31f4000000000002 R15: 00007f29b1b7b4c8 </TASK> INFO: task syz-executor412:3616 blocked for more than 144 seconds. Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor412 state:D stack:28392 pid: 3616 ppid: 3612 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 rwsem_down_write_slowpath+0x59c/0x11e0 kernel/locking/rwsem.c:1182 __down_write_common kernel/locking/rwsem.c:1297 [inline] __down_write_common kernel/locking/rwsem.c:1294 [inline] __down_write kernel/locking/rwsem.c:1306 [inline] down_write_nested+0x139/0x150 kernel/locking/rwsem.c:1663 inode_lock_nested include/linux/fs.h:791 [inline] fuse_reverse_inval_entry+0x51/0x540 fs/fuse/dir.c:1167 fuse_notify_delete fs/fuse/dev.c:1548 [inline] fuse_notify fs/fuse/dev.c:1797 [inline] fuse_dev_do_write+0x1aab/0x2c00 fs/fuse/dev.c:1872 fuse_dev_write+0x150/0x1e0 fs/fuse/dev.c:1956 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 ksys_write+0x127/0x250 fs/read_write.c:631 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+0x63/0xcd RIP: 0033:0x7f29b1af05b9 RSP: 002b:00007f29b1a802f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f29b1b7b4d0 RCX: 00007f29b1af05b9 RDX: 000000000000002c RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f29b1b48084 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f29b1b480a8 R14: 31f4000000000002 R15: 00007f29b1b7b4d8 </TASK> Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8bf88770 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8bf88470 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8bf892c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6492 2 locks held by kworker/u4:4/57: #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90001587da8 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 1 lock held by syslogd/2954: #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:766 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: lookup_slow fs/namei.c:1701 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: walk_component+0x332/0x5a0 fs/namei.c:1993 1 lock held by udevd/2972: #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:766 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: lookup_slow fs/namei.c:1701 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: walk_component+0x332/0x5a0 fs/namei.c:1993 2 locks held by getty/3286: #0: ffff88814adb2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef0/0x13e0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor412/3612: #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:766 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: lookup_slow fs/namei.c:1701 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: walk_component+0x332/0x5a0 fs/namei.c:1993 2 locks held by syz-executor412/3614: #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:766 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: lookup_slow fs/namei.c:1701 [inline] #0: ffff88806f868150 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: walk_component+0x332/0x5a0 fs/namei.c:1993 #1: ffff88806f8685b8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xce/0x100 fs/fuse/inode.c:468 2 locks held by syz-executor412/3616: #0: ffff88814ab26b38 (&fc->killsb){.+.+}-{3:3}, at: fuse_notify_delete fs/fuse/dev.c:1547 [inline] #0: ffff88814ab26b38 (&fc->killsb){.+.+}-{3:3}, at: fuse_notify fs/fuse/dev.c:1797 [inline] #0: ffff88814ab26b38 (&fc->killsb){.+.+}-{3:3}, at: fuse_dev_do_write+0x2567/0x2c00 fs/fuse/dev.c:1872 #1: ffff88806f868150 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:791 [inline] #1: ffff88806f868150 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: fuse_reverse_inval_entry+0x51/0x540 fs/fuse/dir.c:1167 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc18/0xf50 kernel/hung_task.c:369 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 RIP: 0010:__sanitizer_cov_trace_cmp8+0x4/0x20 kernel/kcov.c:276 Code: 00 00 00 00 00 90 48 8b 0c 24 89 f2 89 fe bf 04 00 00 00 e9 1e ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 0c 24 <48> 89 f2 48 89 fe bf 06 00 00 00 e9 fc fe ff ff 66 66 2e 0f 1f 84 RSP: 0018:ffffc90000177da0 EFLAGS: 00000046 RAX: 00000042efb73b7f RBX: ffff8880b9b2ae60 RCX: ffffffff816ff959 RDX: 1ffff110173655cf RSI: 00000042efb73b7f RDI: 00000042efb73b7f RBP: 0000000000000001 R08: 0000000000000007 R09: 7fffffffffffffff R10: 00000042efb73b7f R11: 0000000000000000 R12: 00000042efb73b7f R13: 00000042efb73b7f R14: 0000000000000001 R15: 00000042efb73b7f FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe71c5af990 CR3: 000000000bc8e000 CR4: 0000000000350ee0 Call Trace: <TASK> tick_nohz_stop_tick kernel/time/tick-sched.c:896 [inline] __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:1108 [inline] tick_nohz_idle_stop_tick+0x699/0xbf0 kernel/time/tick-sched.c:1129 cpuidle_idle_call kernel/sched/idle.c:232 [inline] do_idle+0x37b/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:262 secondary_startup_64_no_verify+0xce/0xdb </TASK> --- 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
