audit: type=1400 audit(1538166432.101:40): avc: denied { name_connect } for pid=7055 comm="syz-executor3" dest=20000 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:port_t:s0 tclass=dccp_socket permissive=1 hrtimer: interrupt took 31333 ns ================================================================== BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188 Read of size 8 at addr ffff8801b9e610c0 by task ksoftirqd/1/18 CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.0-rc5+ #37 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+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188 dccp_sk_destruct+0x3c/0x80 net/dccp/proto.c:181 __sk_destruct+0x115/0xbd0 net/core/sock.c:1560 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 run_ksoftirqd+0x94/0x100 kernel/softirq.c:653 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Allocated by task 8487: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44 __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344 dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline] dccp_rcv_state_process+0x11d4/0x1a32 net/dccp/input.c:678 dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638 sk_backlog_rcv include/net/sock.h:931 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2336 release_sock+0xad/0x2c0 net/core/sock.c:2849 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719 __sys_connect+0x37d/0x4c0 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8499: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3756 ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53 __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344 dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538 dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127 dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466 dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196 dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744 ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:383 NF_HOOK include/linux/netfilter.h:287 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:426 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:287 [inline] ipv6_rcv+0x11e/0x650 net/ipv6/ip6_input.c:271 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4891 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5001 process_backlog+0x217/0x760 net/core/dev.c:5807 napi_poll net/core/dev.c:6227 [inline] net_rx_action+0x7c5/0x1950 net/core/dev.c:6293 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801b9e610c0 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 0 bytes inside of 1240-byte region [ffff8801b9e610c0, ffff8801b9e61598) The buggy address belongs to the page: page:ffffea0006e79800 count:1 mapcount:0 mapping:ffff8801cafcd4c0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801cae8c248 ffffea00071ff808 ffff8801cafcd4c0 raw: 0000000000000000 ffff8801b9e60040 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b9e60f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b9e61000: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801b9e61080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801b9e61100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b9e61180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================