============================================ WARNING: possible recursive locking detected 6.0.0-rc4-syzkaller-00133-g64ae13ed4784 #0 Not tainted -------------------------------------------- syz-executor.5/19118 is trying to acquire lock: ffff88814660b0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88814660b0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4270 [inline] ffff88814660b0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 but task is already holding lock: ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4270 [inline] ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 12 locks held by syz-executor.5/19118: #0: ffff888026c6c460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1317 [inline] #0: ffff888026c6c460 (sb_writers#4){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1303 [inline] #0: ffff888026c6c460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1303 #1: ffff888060cf7258 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] #1: ffff888060cf7258 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:510 [inline] #1: ffff888060cf7258 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_file_write_iter+0xbea/0x1660 fs/ext4/file.c:677 #2: ffffffff8bf89400 (rcu_read_lock){....}-{1:2}, at: bio_associate_blkg+0x0/0x210 block/blk-cgroup.c:187 #3: ffffffff8bf89400 (rcu_read_lock){....}-{1:2} , at: bio_associate_blkg_from_css+0xa4/0xee0 block/blk-cgroup.c:1939 #4: ffffc90000007d70 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline] #4: ffffc90000007d70 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1464 #5: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #5: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x292/0x2170 net/ipv4/ip_output.c:214 #6: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x22f/0x3ad0 net/core/dev.c:4173 #7: ffff88801cdfb258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #7: ffff88801cdfb258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #7: ffff88801cdfb258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #7: ffff88801cdfb258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] #7: ffff88801cdfb258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x133c/0x3ad0 net/core/dev.c:4222 #8: ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #8: ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4270 [inline] #8: ffff88814739f0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 #9: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #9: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x292/0x2170 net/ipv4/ip_output.c:214 #10: ffffffff8bf893a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x22f/0x3ad0 net/core/dev.c:4173 #11: ffff888017c2d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #11: ffff888017c2d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #11: ffff888017c2d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #11: ffff888017c2d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] #11: ffff888017c2d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x133c/0x3ad0 net/core/dev.c:4222 stack backtrace: CPU: 0 PID: 19118 Comm: syz-executor.5 Not tainted 6.0.0-rc4-syzkaller-00133-g64ae13ed4784 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] __netif_tx_lock include/linux/netdevice.h:4270 [inline] sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3817 [inline] __dev_queue_xmit+0x1568/0x3ad0 net/core/dev.c:4222 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_resolve_output net/core/neighbour.c:1552 [inline] neigh_resolve_output+0x517/0x840 net/core/neighbour.c:1532 neigh_output include/net/neighbour.h:551 [inline] ip_finish_output2+0x782/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x2d/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x19f/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x67a/0x9e0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x143f/0x3170 net/ipv4/ip_tunnel.c:813 erspan_xmit+0x81d/0x2820 net/ipv4/ip_gre.c:715 __netdev_start_xmit include/linux/netdevice.h:4819 [inline] netdev_start_xmit include/linux/netdevice.h:4833 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x183/0x880 net/core/dev.c:3606 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3817 [inline] __dev_queue_xmit+0x1568/0x3ad0 net/core/dev.c:4222 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_resolve_output net/core/neighbour.c:1552 [inline] neigh_resolve_output+0x517/0x840 net/core/neighbour.c:1532 neigh_output include/net/neighbour.h:551 [inline] ip_finish_output2+0x782/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x2d/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x19f/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 igmpv3_send_cr net/ipv4/igmp.c:720 [inline] igmp_ifc_timer_expire+0x75b/0xf80 net/ipv4/igmp.c:810 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:rcu_rnp_online_cpus kernel/rcu/tree.c:224 [inline] RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:234 [inline] RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:773 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0xa8/0x140 kernel/rcu/tree.c:757 Code: 03 80 3c 02 00 0f 85 87 00 00 00 48 8d 7b 18 48 8b 6b 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 72 <48> b8 00 00 00 00 00 fc ff df 48 8b 5b 18 48 8d 7b 70 48 89 fa 48 RSP: 0018:ffffc900055cf380 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8880b9a3ae40 RCX: ffffc9000d03d000 RDX: 1ffff110173475cb RSI: 0000000000000001 RDI: ffff8880b9a3ae58 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888022ffb000 R13: ffff88801ebd2698 R14: 0000000000000000 R15: ffff888022ffb000 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_held+0x21/0x40 kernel/rcu/update.c:309 __blkg_lookup block/blk-cgroup.h:249 [inline] __blkg_lookup block/blk-cgroup.h:240 [inline] blkg_lookup block/blk-cgroup.h:268 [inline] blkg_lookup block/blk-cgroup.h:264 [inline] blkg_lookup_create block/blk-cgroup.c:395 [inline] blkg_tryget_closest block/blk-cgroup.c:1905 [inline] bio_associate_blkg_from_css+0x1bf/0xee0 block/blk-cgroup.c:1940 bio_associate_blkg+0xc6/0x210 block/blk-cgroup.c:1968 bio_init+0x27b/0x560 block/bio.c:260 blkdev_issue_flush+0x8b/0xd0 block/blk-flush.c:463 ext4_sync_file+0x54d/0xfd0 fs/ext4/fsync.c:177 vfs_fsync_range+0x13a/0x220 fs/sync.c:188 generic_write_sync include/linux/fs.h:2869 [inline] iomap_dio_complete+0x736/0x920 fs/iomap/direct-io.c:128 iomap_dio_rw+0x6f/0xa0 fs/iomap/direct-io.c:694 ext4_dio_write_iter fs/ext4/file.c:566 [inline] ext4_file_write_iter+0xf21/0x1660 fs/ext4/file.c:677 call_write_iter include/linux/fs.h:2187 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:729 do_iter_write+0x182/0x700 fs/read_write.c:855 vfs_iter_write+0x70/0xa0 fs/read_write.c:896 iter_file_splice_write+0x741/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:931 splice_direct_to_actor+0x331/0x8a0 fs/splice.c:886 do_splice_direct+0x1a7/0x270 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1303 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: 0033:0x7f80952893c9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8096385168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f809539bf80 RCX: 00007f80952893c9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007f80952e433f R08: 0000000000000000 R09: 0000000000000000 R10: 00000000f03b0000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe23a721af R14: 00007f8096385300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 03 80 3c 02 00 0f add 0xf00023c(%rax),%eax 6: 85 87 00 00 00 48 test %eax,0x48000000(%rdi) c: 8d 7b 18 lea 0x18(%rbx),%edi f: 48 8b 6b 20 mov 0x20(%rbx),%rbp 13: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1a: fc ff df 1d: 48 89 fa mov %rdi,%rdx 20: 48 c1 ea 03 shr $0x3,%rdx 24: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 28: 75 72 jne 0x9c * 2a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 31: fc ff df 34: 48 8b 5b 18 mov 0x18(%rbx),%rbx 38: 48 8d 7b 70 lea 0x70(%rbx),%rdi 3c: 48 89 fa mov %rdi,%rdx 3f: 48 rex.W