RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f042702c6d4 R13: 00000000004c4f7c R14: 00000000004d8a40 R15: 0000000000000007 dccp_parse_options: DCCP(00000000ae6a8493): Option 32 (len=7) error=9 ================================================================== BUG: KASAN: use-after-free in ccid2_hc_tx_packet_recv+0x2303/0x2673 net/dccp/ccids/ccid2.c:600 Read of size 1 at addr ffff8880a5f2f194 by task syz-executor4/10335 CPU: 0 PID: 10335 Comm: syz-executor4 Not tainted 5.0.0-rc2+ #11 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ccid2_hc_tx_packet_recv+0x2303/0x2673 net/dccp/ccids/ccid2.c:600 ccid_hc_tx_packet_recv net/dccp/ccid.h:192 [inline] dccp_deliver_input_to_ccids+0x202/0x280 net/dccp/input.c:186 dccp_rcv_established net/dccp/input.c:378 [inline] dccp_rcv_established+0x83/0xb0 net/dccp/input.c:368 dccp_v4_do_rcv+0x139/0x190 net/dccp/ipv4.c:659 sk_backlog_rcv include/net/sock.h:936 [inline] __release_sock+0x12e/0x3a0 net/core/sock.c:2310 release_sock+0xac/0x2b0 net/core/sock.c:2826 dccp_sendmsg+0x70e/0xf60 net/dccp/proto.c:818 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x409/0x910 net/socket.c:2116 __sys_sendmmsg+0x246/0x730 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg net/socket.c:2237 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f042702bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f042702bc90 RCX: 0000000000458099 RDX: 04000000000001e6 RSI: 0000000020000c00 RDI: 0000000000000006 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f042702c6d4 R13: 00000000004c4f7c R14: 00000000004d8a40 R15: 0000000000000007 Allocated by task 10335: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3687 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:140 __alloc_skb+0x12d/0x730 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1011 [inline] dccp_send_ack+0xd6/0x360 net/dccp/output.c:580 ccid2_hc_rx_packet_recv+0x139/0x1b0 net/dccp/ccids/ccid2.c:779 ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline] dccp_deliver_input_to_ccids+0xee/0x280 net/dccp/input.c:180 dccp_rcv_established net/dccp/input.c:378 [inline] dccp_rcv_established+0x83/0xb0 net/dccp/input.c:368 dccp_v4_do_rcv+0x139/0x190 net/dccp/ipv4.c:659 sk_backlog_rcv include/net/sock.h:936 [inline] __sk_receive_skb+0x3a9/0xea0 net/core/sock.c:473 dccp_v4_rcv+0x10cb/0x1f80 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0xb6/0xa20 net/ipv4/ip_input.c:208 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_local_deliver+0x1f0/0x740 net/ipv4/ip_input.c:255 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x1f4/0x2f0 net/ipv4/ip_input.c:414 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_rcv+0xed/0x620 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x76d/0x1930 net/core/dev.c:6412 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 Freed by task 10335: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 skb_release_data+0x6ea/0x970 net/core/skbuff.c:573 skb_release_all+0x4d/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] kfree_skb net/core/skbuff.c:659 [inline] kfree_skb+0x199/0x580 net/core/skbuff.c:653 dccp_v4_do_rcv net/dccp/ipv4.c:694 [inline] dccp_v4_do_rcv+0x160/0x190 net/dccp/ipv4.c:654 sk_backlog_rcv include/net/sock.h:936 [inline] __release_sock+0x12e/0x3a0 net/core/sock.c:2310 release_sock+0xac/0x2b0 net/core/sock.c:2826 dccp_sendmsg+0x70e/0xf60 net/dccp/proto.c:818 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x409/0x910 net/socket.c:2116 __sys_sendmmsg+0x246/0x730 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg net/socket.c:2237 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a5f2ed00 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1172 bytes inside of 2048-byte region [ffff8880a5f2ed00, ffff8880a5f2f500) The buggy address belongs to the page: page:ffffea000297cb80 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001922408 ffffea0002412988 ffff88812c3f0c40 raw: 0000000000000000 ffff8880a5f2e480 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a5f2f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5f2f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a5f2f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a5f2f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5f2f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== audit: type=1804 audit(1547918764.630:181): pid=10306 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor0" name="/root/syzkaller-testdir825213776/syzkaller.0sHAjz/1253/memory.events" dev="sda1" ino=17189 res=1