====================================================== WARNING: possible circular locking dependency detected 4.19.195-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/9884 is trying to acquire lock: 0000000037e34b5b (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 but task is already holding lock: 000000006944c134 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] 000000006944c134 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sb->s_type->i_mutex_key#13){+.+.}: inode_lock include/linux/fs.h:748 [inline] __sock_release+0x86/0x2a0 net/socket.c:578 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 delayed_fput+0x56/0x70 fs/file_table.c:304 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #2 ((delayed_fput_work).work){+.+.}: worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #1 ((wq_completion)"events"){+.+.}: flush_scheduled_work include/linux/workqueue.h:599 [inline] tipc_exit_net+0x38/0x60 net/tipc/core.c:100 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #0 (pernet_ops_rwsem){++++}: down_write+0x34/0x90 kernel/locking/rwsem.c:70 unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 bcm_release+0x94/0x700 net/can/bcm.c:1525 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: pernet_ops_rwsem --> (delayed_fput_work).work --> &sb->s_type->i_mutex_key#13 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#13); lock((delayed_fput_work).work); lock(&sb->s_type->i_mutex_key#13); lock(pernet_ops_rwsem); *** DEADLOCK *** 1 lock held by syz-executor.5/9884: #0: 000000006944c134 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 000000006944c134 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 stack backtrace: CPU: 1 PID: 9884 Comm: syz-executor.5 Not tainted 4.19.195-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+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 down_write+0x34/0x90 kernel/locking/rwsem.c:70 unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 bcm_release+0x94/0x700 net/can/bcm.c:1525 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665d9 Code: Bad RIP value. RSP: 002b:00007f6253887188 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000003 RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 000000000000001d RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fffc0f3d7df R14: 00007f6253887300 R15: 0000000000022000 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) SQUASHFS error: lzo decompression failed, data probably corrupt SQUASHFS error: squashfs_read_data failed to read block 0x60 SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f IPVS: ftp: loaded support on port[0] = 21 SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f audit: type=1800 audit(1624981045.890:8): pid=10008 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.2" name="file1" dev="loop2" ino=5 res=0 nla_parse: 17 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. SQUASHFS error: lzo decompression failed, data probably corrupt SQUASHFS error: squashfs_read_data failed to read block 0x60 SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f audit: type=1800 audit(1624981047.070:9): pid=10126 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.2" name="file1" dev="loop2" ino=5 res=0 SQUASHFS error: Unable to read fragment cache entry [60] SQUASHFS error: Unable to read page, block 60, size 1f netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. MINIX-fs: unable to read superblock netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. Dev loop4: unable to read RDB block 1 loop4: unable to read partition table loop4: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop4 () failed (rc=-5) Dev loop4: unable to read RDB block 1 loop4: unable to read partition table EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue loop4: partition table beyond EOD, truncated sctp: [Deprecated]: syz-executor.2 (pid 10403) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor.2 (pid 10403) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead VFS: unable to find oldfs superblock on device loop2 tmpfs: Bad mount option fsmagic tmpfs: Bad mount option fsmagic IPVS: ftp: loaded support on port[0] = 21 overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' audit: type=1800 audit(1624981050.450:10): pid=10677 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.4" name="bus" dev="loop4" ino=1 res=0 overlayfs: missing 'lowerdir' batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 nla_parse: 37 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount option "" netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. audit: type=1804 audit(1624981052.100:11): pid=10900 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/21/bus" dev="sda1" ino=13989 res=1 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. audit: type=1804 audit(1624981052.160:12): pid=10913 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir028840970/syzkaller.pH0mp2/23/cgroup.controllers" dev="sda1" ino=13995 res=1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. audit: type=1804 audit(1624981052.480:13): pid=10946 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/21/bus" dev="sda1" ino=13989 res=1 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. audit: type=1804 audit(1624981052.780:14): pid=10885 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/21/bus" dev="sda1" ino=13989 res=1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. audit: type=1804 audit(1624981052.820:15): pid=10885 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/21/bus" dev="sda1" ino=13989 res=1 audit: type=1804 audit(1624981053.030:16): pid=11001 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/22/bus" dev="sda1" ino=13994 res=1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. device lo entered promiscuous mode audit: type=1804 audit(1624981053.710:17): pid=11006 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.2" name="/root/syzkaller-testdir987172772/syzkaller.dhg7cI/22/bus" dev="sda1" ino=13994 res=1 device tunl0 entered promiscuous mode device gre0 entered promiscuous mode device gretap0 entered promiscuous mode device erspan0 entered promiscuous mode