================================================================== BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188 Read of size 8 at addr ffff8880a10ab640 by task syz-executor.4/10466 CPU: 0 PID: 10466 Comm: syz-executor.4 Not tainted 5.1.0-rc1+ #32 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+0x172/0x1f0 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_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188 dccp_sk_destruct+0x3f/0x90 net/dccp/proto.c:181 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699 __rcu_reclaim kernel/rcu/rcu.h:227 [inline] rcu_do_batch kernel/rcu/tree.c:2475 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2788 [inline] rcu_core+0x928/0x1390 kernel/rcu/tree.c:2769 __do_softirq+0x266/0x95a kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:udp_get_first.isra.0+0x192/0x3f0 net/ipv4/udp.c:2798 Code: a8 45 89 67 08 48 c1 e8 03 80 3c 18 00 0f 85 c3 01 00 00 48 8b 45 c8 4c 8b 70 08 49 8d 7e 10 48 89 fa 48 c1 ea 03 0f b6 14 1a <84> d2 74 09 80 fa 03 0f 8e 95 01 00 00 41 8b 76 10 44 89 e7 89 75 RSP: 0018:ffff88805c17f9c8 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: ffffffff893c39a0 RBX: dffffc0000000000 RCX: ffffc9000e64f000 RDX: 0000000000000000 RSI: ffffffff85eb5255 RDI: ffffffff895fb170 RBP: ffff88805c17fa20 R08: ffff888059e18280 R09: ffff88805d46a372 R10: ffffed100ba8d46f R11: ffff88805d46a37e R12: 00000000000005df R13: ffff8880a125cac0 R14: ffffffff895fb160 R15: ffff888096b4e040 udp_get_idx+0x47/0xb0 net/ipv4/udp.c:2839 udp_seq_next+0x69/0x80 net/ipv4/udp.c:2861 seq_read+0x9ef/0x1130 fs/seq_file.c:258 proc_reg_read+0x1fe/0x2c0 fs/proc/inode.c:227 do_loop_readv_writev fs/read_write.c:700 [inline] do_loop_readv_writev fs/read_write.c:687 [inline] do_iter_read+0x4a9/0x660 fs/read_write.c:921 vfs_readv+0xf0/0x160 fs/read_write.c:983 do_preadv+0x1c4/0x280 fs/read_write.c:1067 __do_sys_preadv fs/read_write.c:1117 [inline] __se_sys_preadv fs/read_write.c:1112 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1112 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458209 Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa8f6faac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458209 RDX: 0000000000000199 RSI: 00000000200017c0 RDI: 0000000000000006 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa8f6fab6d4 R13: 00000000004c4c8e R14: 00000000004d85a8 R15: 00000000ffffffff Allocated by task 10498: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505 slab_post_alloc_hook mm/slab.h:436 [inline] slab_alloc mm/slab.c:3392 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554 ccid_new+0x256/0x3f0 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline] dccp_rcv_state_process+0x116f/0x1935 net/dccp/input.c:680 dccp_v6_do_rcv+0x269/0xbf0 net/dccp/ipv6.c:641 sk_backlog_rcv include/net/sock.h:937 [inline] __release_sock+0x12e/0x3a0 net/core/sock.c:2413 release_sock+0x59/0x1c0 net/core/sock.c:2929 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x59f/0xea0 net/ipv4/af_inet.c:680 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719 __sys_connect+0x266/0x330 net/socket.c:1685 __do_sys_connect net/socket.c:1696 [inline] __se_sys_connect net/socket.c:1693 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1693 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 10504: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3764 ccid_hc_tx_delete+0xc1/0x100 net/dccp/ccid.c:190 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538 dccp_create_openreq_child+0x40c/0x570 net/dccp/minisocks.c:127 dccp_v6_request_recv_sock+0x214/0x1da0 net/dccp/ipv6.c:469 dccp_check_req+0x35c/0x6f0 net/dccp/minisocks.c:196 dccp_v6_rcv+0x6d7/0x191e net/dccp/ipv6.c:747 ip6_protocol_deliver_rcu+0x303/0x16c0 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:443 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x1e7/0x320 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x115/0x1a0 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+0x4fa/0x1070 net/core/dev.c:6412 __do_softirq+0x266/0x95a kernel/softirq.c:293 The buggy address belongs to the object at ffff8880a10ab640 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 0 bytes inside of 1240-byte region [ffff8880a10ab640, ffff8880a10abb18) The buggy address belongs to the page: page:ffffea0002842a80 count:1 mapcount:0 mapping:ffff88809aca09c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffff88809aca1c48 ffff88809aca1c48 ffff88809aca09c0 raw: 0000000000000000 ffff8880a10aa040 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a10ab500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a10ab580: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a10ab600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880a10ab680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a10ab700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================