print_req_error: I/O error, dev loop3, sector 0 EXT4-fs (loop3): VFS: Can't find ext4 filesystem ====================================================== WARNING: possible circular locking dependency detected 4.14.176-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/10929 is trying to acquire lock: input: syz1 as /devices/virtual/input/input688 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}, at: [] __dev_xmit_skb net/core/dev.c:3202 [inline] (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}, at: [] __dev_queue_xmit+0x1f0b/0x25c0 net/core/dev.c:3493 but task is already holding lock: (_xmit_ETHER#2){+.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (_xmit_ETHER#2){+.-.}, at: [] __netif_tx_lock include/linux/netdevice.h:3536 [inline] (_xmit_ETHER#2){+.-.}, at: [] sch_direct_xmit+0x1e4/0x510 net/sched/sch_generic.c:184 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (_xmit_ETHER#2){+.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] __netif_tx_lock include/linux/netdevice.h:3536 [inline] sch_direct_xmit+0x1e4/0x510 net/sched/sch_generic.c:184 __dev_xmit_skb net/core/dev.c:3218 [inline] __dev_queue_xmit+0x1b6e/0x25c0 net/core/dev.c:3493 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x556/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1c2/0x520 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3a/0xc0 net/ipv4/ip_output.c:1422 udp_send_skb+0x614/0xbd0 net/ipv4/udp.c:833 udp_sendmsg+0x1562/0x1b70 net/ipv4/udp.c:1057 inet_sendmsg+0x116/0x4d0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x349/0x840 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] __dev_xmit_skb net/core/dev.c:3202 [inline] __dev_queue_xmit+0x1f0b/0x25c0 net/core/dev.c:3493 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x556/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1c2/0x520 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 iptunnel_xmit+0x583/0x970 net/ipv4/ip_tunnel_core.c:91 ip_tunnel_xmit+0xf67/0x32d8 net/ipv4/ip_tunnel.c:797 erspan_xmit net/ipv4/ip_gre.c:750 [inline] erspan_xmit+0x40f/0x1050 net/ipv4/ip_gre.c:725 __netdev_start_xmit include/linux/netdevice.h:4039 [inline] netdev_start_xmit include/linux/netdevice.h:4048 [inline] xmit_one net/core/dev.c:3009 [inline] dev_hard_start_xmit+0x186/0x890 net/core/dev.c:3025 sch_direct_xmit+0x25f/0x510 net/sched/sch_generic.c:186 __dev_xmit_skb net/core/dev.c:3218 [inline] __dev_queue_xmit+0x1b6e/0x25c0 net/core/dev.c:3493 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x556/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1c2/0x520 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3a/0xc0 net/ipv4/ip_output.c:1422 udp_send_skb+0x614/0xbd0 net/ipv4/udp.c:833 udp_sendmsg+0x1562/0x1b70 net/ipv4/udp.c:1057 inet_sendmsg+0x116/0x4d0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x349/0x840 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(_xmit_ETHER#2); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); lock(_xmit_ETHER#2); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); *** DEADLOCK *** 6 locks held by syz-executor.2/10929: #0: (rcu_read_lock_bh){....}, at: [] lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: (rcu_read_lock_bh){....}, at: [] ip_finish_output2+0x256/0x14a0 net/ipv4/ip_output.c:213 #1: (rcu_read_lock_bh){....}, at: [] __dev_queue_xmit+0x1e2/0x25c0 net/core/dev.c:3459 #2: (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: [] neigh_hh_output include/net/neighbour.h:490 [inline] #2: (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: [] neigh_output include/net/neighbour.h:498 [inline] #2: (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: [] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 #3: (_xmit_ETHER#2){+.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] #3: (_xmit_ETHER#2){+.-.}, at: [] __netif_tx_lock include/linux/netdevice.h:3536 [inline] #3: (_xmit_ETHER#2){+.-.}, at: [] sch_direct_xmit+0x1e4/0x510 net/sched/sch_generic.c:184 #4: (rcu_read_lock_bh){....}, at: [] lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #4: (rcu_read_lock_bh){....}, at: [] ip_finish_output2+0x256/0x14a0 net/ipv4/ip_output.c:213 #5: (rcu_read_lock_bh){....}, at: [] __dev_queue_xmit+0x1e2/0x25c0 net/core/dev.c:3459 stack backtrace: CPU: 1 PID: 10929 Comm: syz-executor.2 Not tainted 4.14.176-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] __dev_xmit_skb net/core/dev.c:3202 [inline] __dev_queue_xmit+0x1f0b/0x25c0 net/core/dev.c:3493 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x556/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1c2/0x520 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 iptunnel_xmit+0x583/0x970 net/ipv4/ip_tunnel_core.c:91 ip_tunnel_xmit+0xf67/0x32d8 net/ipv4/ip_tunnel.c:797 erspan_xmit net/ipv4/ip_gre.c:750 [inline] erspan_xmit+0x40f/0x1050 net/ipv4/ip_gre.c:725 __netdev_start_xmit include/linux/netdevice.h:4039 [inline] netdev_start_xmit include/linux/netdevice.h:4048 [inline] xmit_one net/core/dev.c:3009 [inline] dev_hard_start_xmit+0x186/0x890 net/core/dev.c:3025 sch_direct_xmit+0x25f/0x510 net/sched/sch_generic.c:186 __dev_xmit_skb net/core/dev.c:3218 [inline] __dev_queue_xmit+0x1b6e/0x25c0 net/core/dev.c:3493 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x556/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1c2/0x520 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3a/0xc0 net/ipv4/ip_output.c:1422 udp_send_skb+0x614/0xbd0 net/ipv4/udp.c:833 udp_sendmsg+0x1562/0x1b70 net/ipv4/udp.c:1057 inet_sendmsg+0x116/0x4d0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x349/0x840 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007f4bc0bc2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004fc080 RCX: 000000000045c829 RDX: 0400000000000075 RSI: 0000000020007fc0 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d7 R14: 00000000004cb7aa R15: 00007f4bc0bc36d4 input: syz1 as /devices/virtual/input/input689 input: syz1 as /devices/virtual/input/input692 input: syz1 as /devices/virtual/input/input693 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input694 print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input695 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input696 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input697 EXT4-fs (loop3): VFS: Can't find ext4 filesystem EXT4-fs (loop3): VFS: Can't find ext4 filesystem input: syz1 as /devices/virtual/input/input698 EXT4-fs (loop3): Invalid want_extra_isize 0 EXT4-fs (loop3): Invalid want_extra_isize 0 EXT4-fs (loop3): Unrecognized mount option "debug_want_extra_isize=0x000000000Eë00000" or missing value EXT4-fs (loop3): Unrecognized mount option "debug_want_extra_isize=0x000000000Eë00000" or missing value print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read IPVS: ftp: loaded support on port[0] = 21 EXT4-fs (loop3): Invalid want_extra_isize 0 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input699 audit: type=1400 audit(1587507640.092:206): avc: denied { net_raw } for pid=11210 comm="syz-executor.2" capability=13 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=cap_userns permissive=1 EXT4-fs (loop3): Invalid want_extra_isize 0 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input700 input: syz1 as /devices/virtual/input/input701 input: syz1 as /devices/virtual/input/input702 ptrace attach of "/root/syz-executor.0"[11278] was attempted by "/root/syz-executor.0"[11279] EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input703 input: syz1 as /devices/virtual/input/input704 input: syz1 as /devices/virtual/input/input705 EXT4-fs (loop3): Invalid want_extra_isize 0 EXT4-fs (loop3): Invalid want_extra_isize 0 input: syz1 as /devices/virtual/input/input706 print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read input: syz1 as /devices/virtual/input/input707 input: syz1 as /devices/virtual/input/input708