================================================================== BUG: KASAN: use-after-free in br_dev_xmit+0x12b3/0x13e0 net/bridge/br_device.c:68 Read of size 2 at addr ffff8880957baece by task syz-executor.2/9834 CPU: 0 PID: 9834 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. 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:__find_get_block+0x284/0xde0 fs/buffer.c:1293 Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 64 0a 00 00 48 83 3d 96 0b 41 08 00 0f 84 bf 04 00 00 e8 63 0e b2 ff fb 66 0f 1f 44 00 00 <4d> 85 e4 0f 84 52 02 00 00 e8 4e 0e b2 ff 0f 1f 44 00 00 e8 44 0e RSP: 0018:ffff88804db97a50 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff88804db82100 RBX: 0000000000000000 RCX: 1ffff11009b7053a RDX: 0000000000000000 RSI: ffffffff81b0770d RDI: ffff88804db82984 RBP: 00000000000287e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880556731f8 R13: 00000000000026a4 R14: 0000000000001000 R15: ffff8880556731f8 __getblk_gfp+0x28/0x70 fs/buffer.c:1317 sb_getblk include/linux/buffer_head.h:333 [inline] ext4_getblk+0x162/0x4f0 fs/ext4/inode.c:1000 ext4_bread+0x7c/0x210 fs/ext4/inode.c:1043 __ext4_read_dirblock+0x34/0x9d0 fs/ext4/namei.c:111 ext4_add_entry+0x632/0xbb0 fs/ext4/namei.c:2143 ext4_add_nondir fs/ext4/namei.c:2483 [inline] ext4_symlink+0x5e4/0xc00 fs/ext4/namei.c:3245 vfs_symlink+0x453/0x6c0 fs/namei.c:4129 do_symlinkat+0x258/0x2c0 fs/namei.c:4156 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f09e3c337a7 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 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:00007fffa8fcf5d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f09e3c337a7 RDX: 00007fffa8fcf6b7 RSI: 00007f09e3c8e09d RDI: 00007fffa8fcf6a0 RBP: 0000000000000001 R08: 0000000000000000 R09: 00007fffa8fcf470 R10: 00007fffa8fcf327 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fffa8fcf6a0 Allocated by task 9834: __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 9834: __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 ffff8880957baec0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 14 bytes inside of 2048-byte region [ffff8880957baec0, ffff8880957bb6c0) The buggy address belongs to the page: page:ffffea000255ee80 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002d49108 ffffea000257c588 ffff88813bff0c40 raw: 0000000000000000 ffff8880957ba640 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880957bad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880957bae00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880957bae80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880957baf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880957baf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 48 c1 ea 03 shr $0x3,%rdx 4: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 8: 0f 85 64 0a 00 00 jne 0xa72 e: 48 83 3d 96 0b 41 08 cmpq $0x0,0x8410b96(%rip) # 0x8410bac 15: 00 16: 0f 84 bf 04 00 00 je 0x4db 1c: e8 63 0e b2 ff callq 0xffb20e84 21: fb sti 22: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) * 28: 4d 85 e4 test %r12,%r12 <-- trapping instruction 2b: 0f 84 52 02 00 00 je 0x283 31: e8 4e 0e b2 ff callq 0xffb20e84 36: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3b: e8 .byte 0xe8 3c: 44 0e rex.R (bad)