================================================================== BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: use-after-free in skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline] BUG: KASAN: use-after-free in skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000 Read of size 2324 at addr ffff88801b3932f7 by task syz-executor.5/11990 CPU: 0 PID: 11990 Comm: syz-executor.5 Not tainted 5.11.0-rc4-next-20210119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:397 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:414 check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 memcpy+0x20/0x60 mm/kasan/shadow.c:65 memcpy include/linux/fortify-string.h:191 [inline] skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline] skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000 udp4_ufo_fragment+0x4ae/0x700 net/ipv4/udp_offload.c:363 inet_gso_segment+0x502/0x1110 net/ipv4/af_inet.c:1378 skb_mac_gso_segment+0x26e/0x530 net/core/dev.c:3326 __skb_gso_segment+0x330/0x6e0 net/core/dev.c:3399 skb_gso_segment include/linux/netdevice.h:4708 [inline] validate_xmit_skb+0x69e/0xee0 net/core/dev.c:3644 __dev_queue_xmit+0x988/0x2dd0 net/core/dev.c:4142 packet_snd net/packet/af_packet.c:3006 [inline] packet_sendmsg+0x2406/0x52a0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 __sys_sendto+0x21c/0x320 net/socket.c:1975 __do_sys_sendto net/socket.c:1987 [inline] __se_sys_sendto net/socket.c:1983 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f475b21ec68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219 RDX: 000000000000fc13 RSI: 0000000020000280 RDI: 0000000000000004 RBP: 000000000119bfd8 R08: 0000000000000000 R09: 000000000000002f R10: 0000000000000800 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007fff0390278f R14: 00007f475b21f9c0 R15: 000000000119bf8c Allocated by task 25: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:403 [inline] ____kasan_kmalloc mm/kasan/common.c:434 [inline] ____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:406 kasan_slab_alloc include/linux/kasan.h:209 [inline] slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc_node mm/slub.c:2903 [inline] __kmalloc_node_track_caller+0x191/0x320 mm/slub.c:4569 __kmalloc_reserve net/core/skbuff.c:142 [inline] pskb_expand_head+0x15e/0x1050 net/core/skbuff.c:1636 __skb_cow include/linux/skbuff.h:3181 [inline] skb_cow_head include/linux/skbuff.h:3215 [inline] batadv_skb_head_push+0xe7/0x280 net/batman-adv/soft-interface.c:73 batadv_send_skb_packet+0x10c/0x5f0 net/batman-adv/send.c:86 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x781/0x920 net/batman-adv/bat_iv_ogm.c:1711 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 The buggy address belongs to the object at ffff88801b393000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 759 bytes inside of 1024-byte region [ffff88801b393000, ffff88801b393400) The buggy address belongs to the page: page:00000000930f140c refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801b392000 pfn:0x1b390 head:00000000930f140c order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 ffffea0000822508 ffffea00008b8008 ffff888010041140 raw: ffff88801b392000 0000000000080001 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801b393180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b393200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b393280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b393300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b393380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================