IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 ================================================================== BUG: KASAN: use-after-free in batadv_interface_tx+0x160a/0x18b0 net/batman-adv/soft-interface.c:226 Read of size 2 at addr ffff8880a9218c8b by task syz-executor114/8156 CPU: 0 PID: 8156 Comm: syz-executor114 Not tainted 4.20.0+ #394 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+0x1d3/0x2c6 lib/dump_stack.c:113 print_address_description.cold.5+0x9/0x1ff mm/kasan/report.c:187 kasan_report.cold.6+0x1b/0x39 mm/kasan/report.c:317 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:145 batadv_interface_tx+0x160a/0x18b0 net/batman-adv/soft-interface.c:226 __netdev_start_xmit include/linux/netdevice.h:4382 [inline] netdev_start_xmit include/linux/netdevice.h:4391 [inline] dev_direct_xmit+0x36c/0x6a0 net/core/dev.c:3930 packet_direct_xmit+0xfb/0x170 net/packet/af_packet.c:246 packet_snd net/packet/af_packet.c:2932 [inline] packet_sendmsg+0x298a/0x6ad0 net/packet/af_packet.c:2957 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 __sys_sendto+0x3d7/0x670 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto net/socket.c:1796 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441619 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 3b 0b fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe137acfa8 EFLAGS: 00000216 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441619 RDX: 000000000000000e RSI: 0000000020000180 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004025e0 R13: 0000000000402670 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6631: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:397 kmem_cache_alloc+0x130/0x730 mm/slab.c:3541 anon_vma_chain_alloc mm/rmap.c:130 [inline] anon_vma_clone+0x140/0x710 mm/rmap.c:270 anon_vma_fork+0xf4/0x820 mm/rmap.c:333 dup_mmap kernel/fork.c:545 [inline] dup_mm kernel/fork.c:1324 [inline] copy_mm kernel/fork.c:1379 [inline] copy_process+0x4690/0x8790 kernel/fork.c:1923 _do_fork+0x1cb/0x11d0 kernel/fork.c:2222 __do_sys_clone kernel/fork.c:2329 [inline] __se_sys_clone kernel/fork.c:2323 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2323 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 6633: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3747 anon_vma_chain_free mm/rmap.c:135 [inline] unlink_anon_vmas+0x3b2/0xa60 mm/rmap.c:402 free_pgtables+0x271/0x380 mm/memory.c:393 exit_mmap+0x2cd/0x590 mm/mmap.c:3141 __mmput kernel/fork.c:1051 [inline] mmput+0x247/0x610 kernel/fork.c:1072 exit_mm kernel/exit.c:545 [inline] do_exit+0xdeb/0x2620 kernel/exit.c:854 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a9218c40 which belongs to the cache anon_vma_chain of size 80 The buggy address is located 75 bytes inside of 80-byte region [ffff8880a9218c40, ffff8880a9218c90) The buggy address belongs to the page: page:ffffea0002a48600 count:1 mapcount:0 mapping:ffff8880aa0fca80 index:0xffff8880a9218d90 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002499648 ffffea00029daa88 ffff8880aa0fca80 raw: ffff8880a9218d90 ffff8880a9218000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a9218b80: fb fb fb fb fb fb fc fc fc fc fb fb fb fb fb fb ffff8880a9218c00: fb fb fb fb fc fc fc fc fb fb fb fb fb fb fb fb >ffff8880a9218c80: fb fb fc fc fc fc fb fb fb fb fb fb fb fb fb fb ^ ffff8880a9218d00: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fc fc ffff8880a9218d80: fc fc fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================