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 ffff8880912efc8b by task syz-executor674/7606 CPU: 0 PID: 7606 Comm: syz-executor674 Not tainted 4.20.0-rc7-next-20181224 #189 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: 0033:0x441609 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:00007ffdbbcd50f8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441609 RDX: 000000000000000e RSI: 0000000020000180 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004025d0 R13: 0000000000402660 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4387: 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 kmem_cache_alloc_trace+0x154/0x750 mm/slab.c:3607 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x17b/0xac0 security/apparmor/lsm.c:441 security_file_alloc+0x4c/0xa0 security/security.c:929 __alloc_file+0x139/0x480 fs/file_table.c:105 alloc_empty_file+0x72/0x170 fs/file_table.c:150 path_openat+0x170/0x5160 fs/namei.c:3523 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x780 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4387: 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] kfree+0xcf/0x230 mm/slab.c:3804 kzfree+0x28/0x30 mm/slab_common.c:1589 aa_free_file_ctx security/apparmor/include/file.h:76 [inline] apparmor_file_free_security+0x133/0x1a0 security/apparmor/lsm.c:451 security_file_free+0x4a/0x80 security/security.c:934 file_free fs/file_table.c:54 [inline] __fput+0x519/0xa90 fs/file_table.c:297 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880912efc80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 11 bytes inside of 96-byte region [ffff8880912efc80, ffff8880912efce0) The buggy address belongs to the page: page:ffffea000244bbc0 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0xffff8880912ef380 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002446d88 ffffea00024df088 ffff88812c3f04c0 raw: ffff8880912ef380 ffff8880912ef000 0000000100000014 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880912efb80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880912efc00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880912efc80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880912efd00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880912efd80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ==================================================================