dccp_parse_options: DCCP(000000006d43a462): Option 32 (len=7) error=9 ================================================================== BUG: KASAN: use-after-free in ccid2_hc_tx_packet_recv+0x21ca/0x223a net/dccp/ccids/ccid2.c:587 Read of size 1 at addr ffff88809f8de494 by task syz-executor.5/14835 CPU: 0 PID: 14835 Comm: syz-executor.5 Not tainted 5.6.0-rc5-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 ccid2_hc_tx_packet_recv+0x21ca/0x223a net/dccp/ccids/ccid2.c:587 ccid_hc_tx_packet_recv net/dccp/ccid.h:189 [inline] dccp_deliver_input_to_ccids+0x1e3/0x260 net/dccp/input.c:182 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x7c/0xc0 net/dccp/input.c:364 dccp_v4_do_rcv+0x12e/0x190 net/dccp/ipv4.c:655 sk_backlog_rcv include/net/sock.h:996 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2448 release_sock+0x54/0x1b0 net/core/sock.c:2964 dccp_sendmsg+0x67d/0xd10 net/dccp/proto.c:814 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x302/0x7d0 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmmsg+0x195/0x480 net/socket.c:2487 __do_sys_sendmmsg net/socket.c:2516 [inline] __se_sys_sendmmsg net/socket.c:2513 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2513 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f19e578ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f19e578b6d4 RCX: 000000000045c849 RDX: 04000000000001e6 RSI: 0000000020000c00 RDI: 0000000000000005 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000008d2 R14: 00000000004cb76a R15: 0000000000000004 Allocated by task 14835: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:142 __alloc_skb+0xef/0x5a0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1081 [inline] dccp_send_ack+0xcc/0x360 net/dccp/output.c:576 ccid2_hc_rx_packet_recv+0x130/0x1a0 net/dccp/ccids/ccid2.c:766 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids+0xe1/0x260 net/dccp/input.c:176 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x7c/0xc0 net/dccp/input.c:364 dccp_v4_do_rcv+0x12e/0x190 net/dccp/ipv4.c:655 sk_backlog_rcv include/net/sock.h:996 [inline] __sk_receive_skb+0x323/0xc80 net/core/sock.c:519 dccp_v4_rcv+0xf1b/0x1d43 net/dccp/ipv4.c:876 ip_protocol_deliver_rcu+0x57/0x880 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x220/0x360 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_local_deliver+0x1c8/0x4e0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_rcv+0xd0/0x3c0 net/ipv4/ip_input.c:538 __netif_receive_skb_one_core+0xf5/0x160 net/core/dev.c:5187 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5301 process_backlog+0x21e/0x7a0 net/core/dev.c:6133 napi_poll net/core/dev.c:6571 [inline] net_rx_action+0x4c2/0x1070 net/core/dev.c:6639 __do_softirq+0x26c/0x99d kernel/softirq.c:292 Freed by task 14835: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 skb_free_head+0x8b/0xa0 net/core/skbuff.c:590 skb_release_data+0x42e/0x8b0 net/core/skbuff.c:610 skb_release_all+0x46/0x60 net/core/skbuff.c:664 __kfree_skb net/core/skbuff.c:678 [inline] kfree_skb net/core/skbuff.c:696 [inline] kfree_skb+0xfa/0x410 net/core/skbuff.c:690 dccp_v4_do_rcv net/dccp/ipv4.c:690 [inline] dccp_v4_do_rcv+0x155/0x190 net/dccp/ipv4.c:650 sk_backlog_rcv include/net/sock.h:996 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2448 release_sock+0x54/0x1b0 net/core/sock.c:2964 dccp_sendmsg+0x67d/0xd10 net/dccp/proto.c:814 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x302/0x7d0 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmmsg+0x195/0x480 net/socket.c:2487 __do_sys_sendmmsg net/socket.c:2516 [inline] __se_sys_sendmmsg net/socket.c:2513 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2513 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88809f8de000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1172 bytes inside of 2048-byte region [ffff88809f8de000, ffff88809f8de800) The buggy address belongs to the page: page:ffffea00027e3780 refcount:1 mapcount:0 mapping:ffff8880aa000e00 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000243e248 ffffea00029d3508 ffff8880aa000e00 raw: 0000000000000000 ffff88809f8de000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809f8de380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809f8de400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809f8de480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809f8de500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809f8de580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================