RDX: 0000000000000000 RSI: 0000000020000400 RDI: 0000000000000003 RBP: 00007f8d260c208d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc0c9be59f R14: 00007f8d2497a300 R15: 0000000000022000 ================================================================== BUG: KASAN: use-after-free in br_dev_xmit+0x12b3/0x13e0 net/bridge/br_device.c:68 Read of size 2 at addr ffff888095552d0e by task kworker/u4:2/61 CPU: 0 PID: 61 Comm: kworker/u4:2 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load_n_noabort+0x8b/0xa0 mm/kasan/report.c:443 br_dev_xmit+0x12b3/0x13e0 net/bridge/br_device.c:68 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 vlan_dev_hard_start_xmit+0x38f/0x800 net/8021q/vlan_dev.c:131 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 neigh_connected_output+0x3e8/0x5e0 net/core/neighbour.c:1403 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209 dst_output include/net/dst.h:455 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] mld_sendpack+0x674/0x1060 net/ipv6/mcast.c:1681 mld_send_cr net/ipv6/mcast.c:1977 [inline] mld_ifc_timer_expire+0x616/0xdf0 net/ipv6/mcast.c:2476 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:784 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:806 [inline] RIP: 0010:lock_release+0xd0/0x8b0 kernel/locking/lockdep.c:3923 Code: 80 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 c3 06 00 00 48 83 3d c6 37 a6 08 00 0f 84 1b 05 00 00 <9c> 58 0f 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 04 24 48 RSP: 0018:ffff8880b51d7a90 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3050 RBX: ffff8880b51bc200 RCX: ffffffff86d66681 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880b51bca84 RBP: ffffffff89f85fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff11016a3af55 R13: ffffffff86d664b1 R14: 0000000000000002 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:247 [inline] rcu_read_unlock include/linux/rcupdate.h:681 [inline] inet_twsk_purge+0x558/0x7c0 net/ipv4/inet_timewait_sock.c:298 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:156 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554 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 Allocated by task 61: __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0xae/0x560 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:995 [inline] alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5333 sock_alloc_send_pskb+0x6e1/0x830 net/core/sock.c:2108 mld_newpack+0x1d2/0x760 net/ipv6/mcast.c:1609 add_grhead+0x265/0x330 net/ipv6/mcast.c:1712 add_grec+0xe3c/0x10b0 net/ipv6/mcast.c:1843 mld_send_cr net/ipv6/mcast.c:1969 [inline] mld_ifc_timer_expire+0x5a2/0xdf0 net/ipv6/mcast.c:2476 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 Freed by task 61: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 skb_free_head net/core/skbuff.c:563 [inline] pskb_expand_head+0x327/0xf20 net/core/skbuff.c:1506 __skb_cow include/linux/skbuff.h:2977 [inline] skb_cow_head include/linux/skbuff.h:3011 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:346 [inline] vlan_insert_inner_tag include/linux/if_vlan.h:416 [inline] vlan_insert_tag include/linux/if_vlan.h:441 [inline] vlan_insert_tag_set_proto include/linux/if_vlan.h:460 [inline] __allowed_ingress net/bridge/br_vlan.c:437 [inline] br_allowed_ingress+0x376/0xed0 net/bridge/br_vlan.c:514 br_dev_xmit+0x3e5/0x13e0 net/bridge/br_device.c:64 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 vlan_dev_hard_start_xmit+0x38f/0x800 net/8021q/vlan_dev.c:131 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 neigh_connected_output+0x3e8/0x5e0 net/core/neighbour.c:1403 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209 dst_output include/net/dst.h:455 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] mld_sendpack+0x674/0x1060 net/ipv6/mcast.c:1681 mld_send_cr net/ipv6/mcast.c:1977 [inline] mld_ifc_timer_expire+0x616/0xdf0 net/ipv6/mcast.c:2476 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 The buggy address belongs to the object at ffff888095552d00 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 14 bytes inside of 2048-byte region [ffff888095552d00, ffff888095553500) The buggy address belongs to the page: page:ffffea0002555480 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0xffff888095553580 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002917b88 ffffea00024f4388 ffff88813bff0c40 raw: ffff888095553580 ffff888095552480 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095552c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095552c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888095552d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888095552d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095552e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 7: fc ff df a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 12: 0f 85 c3 06 00 00 jne 0x6db 18: 48 83 3d c6 37 a6 08 cmpq $0x0,0x8a637c6(%rip) # 0x8a637e6 1f: 00 20: 0f 84 1b 05 00 00 je 0x541 * 26: 9c pushfq <-- trapping instruction 27: 58 pop %rax 28: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 2d: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 34: fc ff df 37: 48 89 04 24 mov %rax,(%rsp) 3b: 48 rex.W