============================================ WARNING: possible recursive locking detected 4.19.204-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/11656 is trying to acquire lock: 000000000227af59 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] 000000000227af59 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3838 [inline] 000000000227af59 (_xmit_ETHER#2){+.-.}, at: __dev_queue_xmit+0x2592/0x2e00 net/core/dev.c:3834 but task is already holding lock: 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3838 [inline] 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x254/0xf50 net/sched/sch_generic.c:330 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); audit: type=1804 audit(1629715950.461:41): pid=11661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.3" name="/root/syzkaller-testdir019227180/syzkaller.oqHoGA/19/cgroup.controllers" dev="sda1" ino=14106 res=1 lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor.1/11656: #0: 0000000016e6e422 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 0000000016e6e422 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x28d/0x15a0 net/ipv4/ip_output.c:214 #1: 0000000016e6e422 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x1e2/0x2e00 net/core/dev.c:3773 #2: 00000000556f8737 (&(&sch->seqlock)->rlock){+...}, at: spin_trylock include/linux/spinlock.h:339 [inline] #2: 00000000556f8737 (&(&sch->seqlock)->rlock){+...}, at: qdisc_run_begin include/net/sch_generic.h:130 [inline] #2: 00000000556f8737 (&(&sch->seqlock)->rlock){+...}, at: qdisc_run include/net/pkt_sched.h:119 [inline] #2: 00000000556f8737 (&(&sch->seqlock)->rlock){+...}, at: __dev_xmit_skb net/core/dev.c:3451 [inline] #2: 00000000556f8737 (&(&sch->seqlock)->rlock){+...}, at: __dev_queue_xmit+0x278b/0x2e00 net/core/dev.c:3807 #3: 00000000813e71af (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 #4: 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] #4: 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3838 [inline] #4: 00000000b9f4d0cc (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x254/0xf50 net/sched/sch_generic.c:330 #5: 0000000016e6e422 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #5: 0000000016e6e422 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x28d/0x15a0 net/ipv4/ip_output.c:214 #6: 0000000016e6e422 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x1e2/0x2e00 net/core/dev.c:3773 stack backtrace: CPU: 0 PID: 11656 Comm: syz-executor.1 Not tainted 4.19.204-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_deadlock_bug kernel/locking/lockdep.c:1764 [inline] check_deadlock kernel/locking/lockdep.c:1808 [inline] validate_chain kernel/locking/lockdep.c:2404 [inline] __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] __netif_tx_lock include/linux/netdevice.h:3838 [inline] __dev_queue_xmit+0x2592/0x2e00 net/core/dev.c:3834 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip_finish_output2+0xd76/0x15a0 net/ipv4/ip_output.c:230 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x203/0x5f0 net/ipv4/ip_output.c:406 dst_output include/net/dst.h:455 [inline] ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125 iptunnel_xmit+0x63b/0x9d0 net/ipv4/ip_tunnel_core.c:91 ip_tunnel_xmit+0x13ad/0x3850 net/ipv4/ip_tunnel.c:790 erspan_xmit+0xd6e/0x27e0 net/ipv4/ip_gre.c:754 __netdev_start_xmit include/linux/netdevice.h:4345 [inline] netdev_start_xmit include/linux/netdevice.h:4359 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 sch_direct_xmit+0x2d6/0xf50 net/sched/sch_generic.c:332 qdisc_restart net/sched/sch_generic.c:395 [inline] __qdisc_run+0x4d0/0x1640 net/sched/sch_generic.c:403 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:3451 [inline] __dev_queue_xmit+0x2102/0x2e00 net/core/dev.c:3807 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip_finish_output2+0xd76/0x15a0 net/ipv4/ip_output.c:230 ip_do_fragment+0x1e1a/0x2620 net/ipv4/ip_output.c:680 ip_fragment.constprop.0+0x174/0x240 net/ipv4/ip_output.c:551 ip_finish_output+0xa35/0x10b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x203/0x5f0 net/ipv4/ip_output.c:406 dst_output include/net/dst.h:455 [inline] ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125 ip_send_skb+0x3e/0xe0 net/ipv4/ip_output.c:1451 udp_send_skb+0x6a4/0x1170 net/ipv4/udp.c:848 udp_sendmsg+0x1cb4/0x2550 net/ipv4/udp.c:1135 udpv6_sendmsg+0x14b2/0x2ae0 net/ipv6/udp.c:1224 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x3b3/0x8e0 net/socket.c:2225 __sys_sendmmsg+0x195/0x470 net/socket.c:2320 __do_sys_sendmmsg net/socket.c:2349 [inline] __se_sys_sendmmsg net/socket.c:2346 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2346 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1d452da188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0400000000000132 RSI: 0000000020004d80 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000004000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffdf24e694f R14: 00007f1d452da300 R15: 0000000000022000 device vlan0 entered promiscuous mode audit: type=1804 audit(1629715951.301:42): pid=11663 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.3" name="/root/syzkaller-testdir019227180/syzkaller.oqHoGA/19/cgroup.controllers" dev="sda1" ino=14106 res=1 NILFS (loop2): unable to read secondary superblock (blocksize = 1024) NILFS (loop2): broken superblock, retrying with spare superblock (blocksize = 1024) NILFS (loop2): unrecognized mount option "snapshot=0x0000000000000000" device vlan0 left promiscuous mode NILFS (loop2): unable to read secondary superblock (blocksize = 1024) netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. NILFS (loop2): broken superblock, retrying with spare superblock (blocksize = 1024) NILFS (loop2): unrecognized mount option "snapshot=0x0000000000000000" NILFS (loop2): unable to read secondary superblock (blocksize = 1024) device vlan0 entered promiscuous mode NILFS (loop2): broken superblock, retrying with spare superblock (blocksize = 1024) NILFS (loop2): unrecognized mount option "snapshot=0x0000000000000000" NILFS (loop2): unable to read secondary superblock (blocksize = 1024) NILFS (loop2): broken superblock, retrying with spare superblock (blocksize = 1024) NILFS (loop2): unrecognized mount option "snapshot=0x0000000000000000" device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. NILFS (loop2): unable to read secondary superblock (blocksize = 1024) NILFS (loop2): broken superblock, retrying with spare superblock (blocksize = 1024) NILFS (loop2): unrecognized mount option "snapshot=0x0000000000000000" F2FS-fs (loop5): Invalid Fs Meta Ino: node(1) meta(0) root(3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock device vlan0 entered promiscuous mode F2FS-fs (loop5): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop5): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop5): Invalid Fs Meta Ino: node(1) meta(0) root(3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop5): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop5): Can't find valid F2FS filesystem in 2th superblock device vlan0 left promiscuous mode IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 'syz-executor.3': attribute type 3 has an invalid length. IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready device vlan0 entered promiscuous mode syz-executor.3 (11826): drop_caches: 2 device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. syz-executor.3 (11819): drop_caches: 2 F2FS-fs (loop5): Invalid Fs Meta Ino: node(1) meta(0) root(3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock device vlan0 entered promiscuous mode syz-executor.3 (11887): drop_caches: 1 device vlan0 left promiscuous mode 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'. netlink: 'syz-executor.1': attribute type 3 has an invalid length. netlink: 'syz-executor.3': attribute type 3 has an invalid length. syz-executor.1 (11888): drop_caches: 1 device vlan0 entered promiscuous mode syz-executor.3 (11957): drop_caches: 2 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 'syz-executor.3': attribute type 3 has an invalid length. device vlan0 entered promiscuous mode syz-executor.3 (12004): drop_caches: 2 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device vlan0 left promiscuous mode IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. device vlan0 entered promiscuous mode netlink: 'syz-executor.3': attribute type 3 has an invalid length. device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready device vlan0 entered promiscuous mode syz-executor.3 (12083): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 'syz-executor.3': attribute type 3 has an invalid length. syz-executor.3 (12136): drop_caches: 2 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device vlan0 entered promiscuous mode device vlan0 entered promiscuous mode device vlan0 left promiscuous mode device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. syz-executor.3 (12185): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 left promiscuous mode syz-executor.3 (12219): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 entered promiscuous mode device vlan0 left promiscuous mode device vlan0 left promiscuous mode device vlan0 entered promiscuous mode syz-executor.3 (12271): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 left promiscuous mode IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready device vlan0 left promiscuous mode IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready syz-executor.3 (12321): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 entered promiscuous mode device vlan0 left promiscuous mode device vlan0 left promiscuous mode device vlan0 entered promiscuous mode syz-executor.3 (12367): drop_caches: 2 device vlan0 entered promiscuous mode device vlan0 left promiscuous mode device vlan0 left promiscuous mode device vlan0 entered promiscuous mode nla_parse: 6 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. device vlan0 left promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. device vlan0 entered promiscuous mode syz-executor.3 (12423): drop_caches: 2