bisecting fixing commit since 6500aa436df40a46998f7a56a32e8199a3513e6d building syzkaller on 442206d76b974cca2d83ec763d4cf5ee829eb7d6 testing commit 6500aa436df40a46998f7a56a32e8199a3513e6d with gcc (GCC) 8.1.0 kernel signature: 66f0a1cdf00961d2a768644739a46cde213ccb8e951fb1880ee89ac9b0fd91be all runs: crashed: INFO: task hung in __fuse_request_send testing current HEAD 357668399cf70ccdc0ee8967bff3448d0f4f9ae1 testing commit 357668399cf70ccdc0ee8967bff3448d0f4f9ae1 with gcc (GCC) 8.1.0 kernel signature: 630fd8b9b1b3842f8b6a20c1e760bd08c5be06e2fd0ae07cb87e39fcf29ca609 all runs: crashed: INFO: task hung in __fuse_request_send revisions tested: 2, total time: 30m14.358197515s (build: 17m45.117531419s, test: 11m34.338737714s) the crash still happens on HEAD commit msg: Linux 4.19.103 crash: INFO: task hung in __fuse_request_send IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 INFO: task syz-executor.2:7158 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27192 7158 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 request_wait_answer+0x2fe/0x620 fs/fuse/dev.c:485 __fuse_request_send+0xff/0x190 fs/fuse/dev.c:505 fuse_request_send+0x41/0x80 fs/fuse/dev.c:518 fuse_simple_request+0x2b4/0x610 fs/fuse/dev.c:576 fuse_lookup_name+0x244/0x590 fs/fuse/dir.c:330 fuse_lookup+0xf3/0x3b0 fs/fuse/dir.c:368 __lookup_slow+0x216/0x400 fs/namei.c:1672 lookup_slow+0x51/0x70 fs/namei.c:1689 walk_component+0x694/0x2320 fs/namei.c:1811 lookup_last fs/namei.c:2274 [inline] path_lookupat.isra.43+0x180/0x850 fs/namei.c:2319 filename_lookup.part.57+0x160/0x360 fs/namei.c:2349 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_stat include/linux/fs.h:3128 [inline] __do_sys_newstat+0x85/0xe0 fs/stat.c:337 __se_sys_newstat fs/stat.c:333 [inline] __x64_sys_newstat+0x4f/0x70 fs/stat.c:333 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007fad7b5b6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad7b5b76d4 R13: 00000000004e52fb R14: 00000000004de648 R15: 00000000ffffffff INFO: task syz-executor.2:7160 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29704 7160 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] lock_mount+0x82/0x290 fs/namespace.c:2039 do_add_mount+0x22/0x310 fs/namespace.c:2416 do_new_mount fs/namespace.c:2483 [inline] do_mount+0x1290/0x2410 fs/namespace.c:2799 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007fad7b595c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004592c9 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000000000000 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 00007fad7b5966d4 R13: 00000000004c570b R14: 00000000004d9aa0 R15: 00000000ffffffff INFO: task syz-executor.2:7161 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28616 7161 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 fuse_notify_delete fs/fuse/dev.c:1568 [inline] fuse_notify fs/fuse/dev.c:1802 [inline] fuse_dev_do_write+0xb7d/0x2350 fs/fuse/dev.c:1877 fuse_dev_write+0x12a/0x1b0 fs/fuse/dev.c:1961 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x443/0x890 fs/read_write.c:487 vfs_write+0x150/0x4d0 fs/read_write.c:549 ksys_write+0x103/0x260 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:608 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007fad7b574c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004592c9 RDX: 000000000000002e RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad7b5756d4 R13: 00000000004c8aa3 R14: 00000000004df6e0 R15: 00000000ffffffff INFO: task syz-executor.2:7188 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27960 7188 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] lock_mount+0x82/0x290 fs/namespace.c:2039 do_add_mount+0x22/0x310 fs/namespace.c:2416 do_new_mount fs/namespace.c:2483 [inline] do_mount+0x1290/0x2410 fs/namespace.c:2799 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007fad7b553c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004592c9 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c118 R08: 0000000020000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad7b5546d4 R13: 00000000004c56df R14: 00000000004d9b60 R15: 00000000ffffffff INFO: task syz-executor.2:7189 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29144 7189 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x21c/0x3e0 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:757 [inline] lookup_slow+0x43/0x70 fs/namei.c:1688 walk_component+0x694/0x2320 fs/namei.c:1811 lookup_last fs/namei.c:2274 [inline] path_lookupat.isra.43+0x180/0x850 fs/namei.c:2319 filename_lookup.part.57+0x160/0x360 fs/namei.c:2349 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_stat include/linux/fs.h:3128 [inline] __do_sys_newstat+0x85/0xe0 fs/stat.c:337 __se_sys_newstat fs/stat.c:333 [inline] __x64_sys_newstat+0x4f/0x70 fs/stat.c:333 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007fad7b532c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad7b5336d4 R13: 00000000004e52fb R14: 00000000004de648 R15: 00000000ffffffff INFO: task syz-executor.4:7163 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27720 7163 7142 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 request_wait_answer+0x2fe/0x620 fs/fuse/dev.c:485 __fuse_request_send+0xff/0x190 fs/fuse/dev.c:505 fuse_request_send+0x41/0x80 fs/fuse/dev.c:518 fuse_simple_request+0x2b4/0x610 fs/fuse/dev.c:576 fuse_lookup_name+0x244/0x590 fs/fuse/dir.c:330 fuse_lookup+0xf3/0x3b0 fs/fuse/dir.c:368 __lookup_slow+0x216/0x400 fs/namei.c:1672 lookup_slow+0x51/0x70 fs/namei.c:1689 walk_component+0x694/0x2320 fs/namei.c:1811 lookup_last fs/namei.c:2274 [inline] path_lookupat.isra.43+0x180/0x850 fs/namei.c:2319 filename_lookup.part.57+0x160/0x360 fs/namei.c:2349 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_stat include/linux/fs.h:3128 [inline] __do_sys_newstat+0x85/0xe0 fs/stat.c:337 __se_sys_newstat fs/stat.c:333 [inline] __x64_sys_newstat+0x4f/0x70 fs/stat.c:333 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007f4c1a856c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c1a8576d4 R13: 00000000004e52fb R14: 00000000004de648 R15: 00000000ffffffff INFO: task syz-executor.4:7165 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29496 7165 7142 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] lock_mount+0x82/0x290 fs/namespace.c:2039 do_add_mount+0x22/0x310 fs/namespace.c:2416 do_new_mount fs/namespace.c:2483 [inline] do_mount+0x1290/0x2410 fs/namespace.c:2799 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007f4c1a835c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004592c9 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000000000000 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 00007f4c1a8366d4 R13: 00000000004c570b R14: 00000000004d9aa0 R15: 00000000ffffffff INFO: task syz-executor.4:7169 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28920 7169 7142 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 fuse_notify_delete fs/fuse/dev.c:1568 [inline] fuse_notify fs/fuse/dev.c:1802 [inline] fuse_dev_do_write+0xb7d/0x2350 fs/fuse/dev.c:1877 fuse_dev_write+0x12a/0x1b0 fs/fuse/dev.c:1961 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x443/0x890 fs/read_write.c:487 vfs_write+0x150/0x4d0 fs/read_write.c:549 ksys_write+0x103/0x260 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:608 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007f4c1a814c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004592c9 RDX: 000000000000002e RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c1a8156d4 R13: 00000000004c8aa3 R14: 00000000004df6e0 R15: 00000000ffffffff INFO: task syz-executor.4:7193 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27960 7193 7142 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x5c6/0xbf0 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] lock_mount+0x82/0x290 fs/namespace.c:2039 do_add_mount+0x22/0x310 fs/namespace.c:2416 do_new_mount fs/namespace.c:2483 [inline] do_mount+0x1290/0x2410 fs/namespace.c:2799 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007f4c1a7f3c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004592c9 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c118 R08: 0000000020000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c1a7f46d4 R13: 00000000004c56df R14: 00000000004d9b60 R15: 00000000ffffffff INFO: task syz-executor.4:7194 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29144 7194 7142 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x21c/0x3e0 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:757 [inline] lookup_slow+0x43/0x70 fs/namei.c:1688 walk_component+0x694/0x2320 fs/namei.c:1811 lookup_last fs/namei.c:2274 [inline] path_lookupat.isra.43+0x180/0x850 fs/namei.c:2319 filename_lookup.part.57+0x160/0x360 fs/namei.c:2349 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_stat include/linux/fs.h:3128 [inline] __do_sys_newstat+0x85/0xe0 fs/stat.c:337 __se_sys_newstat fs/stat.c:333 [inline] __x64_sys_newstat+0x4f/0x70 fs/stat.c:333 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: 24 48 c7 44 24 10 09 00 00 00 e8 82 ad ff ff 0f b6 44 24 18 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 8a 8f ff ff eb a8 cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 RSP: 002b:00007f4c1a7d2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c1a7d36d4 R13: 00000000004e52fb R14: 00000000004de648 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1037: #0: 000000001fe23557 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/6896: #0: 00000000acfe75d5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 2 locks held by getty/7019: #0: 00000000eb5c027d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006d61a1bf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7020: #0: 00000000c50b6635 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000018bca616 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7021: #0: 0000000088182dd9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000d6a8eca4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7022: #0: 00000000575321cd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000001928d715 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7023: #0: 00000000ebe019b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000aa2d538a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7024: #0: 00000000be766b41 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000031ad957b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by getty/7025: #0: 0000000086afa987 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b96fd044 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x1ee/0x1910 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.2/7158: #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 000000008c4eb360 (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 1 lock held by syz-executor.2/7160: #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 2 locks held by syz-executor.2/7161: #0: 000000002e42a0cc (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 000000002e42a0cc (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 000000002e42a0cc (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.2/7188: #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.2/7189: #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 00000000a743d820 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 2 locks held by syz-executor.4/7163: #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 00000000cb985664 (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 1 lock held by syz-executor.4/7165: #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 2 locks held by syz-executor.4/7169: #0: 000000005be00544 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 000000005be00544 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 000000005be00544 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.4/7193: #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.4/7194: #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 0000000009ed5949 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 2 locks held by syz-executor.0/7168: #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 00000000388e1886 (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 1 lock held by syz-executor.0/7170: #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 2 locks held by syz-executor.0/7171: #0: 00000000c34174d8 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 00000000c34174d8 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 00000000c34174d8 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.0/7197: #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.0/7198: #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 0000000022e965f4 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 2 locks held by syz-executor.3/7174: #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 0000000049dbe9db (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 2 locks held by syz-executor.3/7175: #0: 00000000a5033fc5 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 00000000a5033fc5 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 00000000a5033fc5 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.3/7176: #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.3/7201: #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.3/7202: #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000008cba7668 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 2 locks held by syz-executor.5/7179: #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 000000004c13380a (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 1 lock held by syz-executor.5/7184: #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 2 locks held by syz-executor.5/7186: #0: 000000008193f978 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 000000008193f978 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 000000008193f978 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.5/7205: #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.5/7206: #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000003958d901 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 2 locks held by syz-executor.1/7183: #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 #1: 000000005f546b02 (&fi->mutex){+.+.}, at: fuse_lock_inode+0x9a/0xc0 fs/fuse/inode.c:365 2 locks held by syz-executor.1/7185: #0: 00000000c81c2e51 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1565 [inline] #0: 00000000c81c2e51 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1802 [inline] #0: 00000000c81c2e51 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x19c5/0x2350 fs/fuse/dev.c:1877 #1: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #1: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: fuse_reverse_inval_entry+0x9a/0x5d0 fs/fuse/dir.c:987 1 lock held by syz-executor.1/7187: #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.1/7209: #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: lock_mount+0x82/0x290 fs/namespace.c:2039 1 lock held by syz-executor.1/7210: #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:757 [inline] #0: 000000003e352488 (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1037 Comm: khungtaskd Not tainted 4.19.103-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.4+0x3e/0x76 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xe6/0x11a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x12/0x20 arch/x86/include/asm/irqflags.h:60