================================================================== BUG: KASAN: use-after-free in decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3393 Read of size 1 at addr ffff88801b9888af by task syz-executor.5/19986 CPU: 0 PID: 19986 Comm: syz-executor.5 Not tainted 5.10.0-rc2-next-20201105-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+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3393 __xfrm_decode_session net/xfrm/xfrm_policy.c:3485 [inline] __xfrm_policy_check+0x2fa/0x2850 net/xfrm/xfrm_policy.c:3540 __xfrm_policy_check2 include/net/xfrm.h:1097 [inline] xfrm_policy_check include/net/xfrm.h:1106 [inline] sctp_rcv+0x12b0/0x2e30 net/sctp/input.c:202 sctp6_rcv+0x22/0x40 net/sctp/ipv6.c:1078 ip6_protocol_deliver_rcu+0x2e8/0x1680 net/ipv6/ip6_input.c:433 ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:447 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5315 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5429 process_backlog+0x232/0x6c0 net/core/dev.c:6319 napi_poll net/core/dev.c:6763 [inline] net_rx_action+0x4dc/0x1100 net/core/dev.c:6833 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:343 [inline] do_softirq+0xb5/0xe0 kernel/softirq.c:330 __local_bh_enable_ip+0xf0/0x110 kernel/softirq.c:195 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:731 [inline] ip6_finish_output2+0x71f/0x16c0 net/ipv6/ip6_output.c:118 __ip6_finish_output net/ipv6/ip6_output.c:143 [inline] __ip6_finish_output+0x447/0xab0 net/ipv6/ip6_output.c:128 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x1db/0x520 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:441 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip6_xmit+0x1258/0x1e80 net/ipv6/ip6_output.c:280 sctp_v6_xmit+0xbf3/0xfe0 net/sctp/ipv6.c:223 sctp_packet_transmit+0x1f44/0x32f0 net/sctp/output.c:627 sctp_outq_flush_transports net/sctp/outqueue.c:1147 [inline] sctp_outq_flush+0x2aa/0x2580 net/sctp/outqueue.c:1195 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1801 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] sctp_do_sm+0x74e/0x5120 net/sctp/sm_sideeffect.c:1156 sctp_assoc_bh_rcv+0x386/0x6c0 net/sctp/associola.c:1048 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x19e/0x5c0 net/sctp/input.c:344 sk_backlog_rcv include/net/sock.h:1010 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2523 release_sock+0x54/0x1b0 net/core/sock.c:3053 sctp_connect net/sctp/socket.c:4732 [inline] sctp_inet_connect+0x16e/0x200 net/sctp/socket.c:4745 __sys_connect_file+0x155/0x1a0 net/socket.c:1852 __sys_connect+0x161/0x190 net/socket.c:1869 __do_sys_connect net/socket.c:1879 [inline] __se_sys_connect net/socket.c:1876 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1876 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 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:00007ff1246f6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000002400 RCX: 000000000045deb9 RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000004 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff5662391f R14: 00007ff1246f79c0 R15: 000000000118bf2c Allocated by task 19724: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49 kasan_set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:480 slab_post_alloc_hook mm/slab.h:506 [inline] slab_alloc_node mm/slub.c:2901 [inline] slab_alloc mm/slub.c:2909 [inline] kmem_cache_alloc+0x12a/0x470 mm/slub.c:2914 kmem_cache_zalloc include/linux/slab.h:654 [inline] __alloc_file+0x21/0x280 fs/file_table.c:101 alloc_empty_file+0x6d/0x170 fs/file_table.c:150 alloc_file+0x5e/0x5a0 fs/file_table.c:192 alloc_file_pseudo+0x165/0x250 fs/file_table.c:232 sock_alloc_file+0x4f/0x190 net/socket.c:411 sock_map_fd net/socket.c:435 [inline] __sys_socket+0x13d/0x200 net/socket.c:1524 __do_sys_socket net/socket.c:1529 [inline] __se_sys_socket net/socket.c:1527 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1527 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 19717: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49 kasan_set_track+0x1c/0x30 mm/kasan/common.c:57 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:356 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:438 slab_free_hook mm/slub.c:1545 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1583 slab_free mm/slub.c:3155 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3171 rcu_do_batch kernel/rcu/tree.c:2492 [inline] rcu_core+0x5e4/0xef0 kernel/rcu/tree.c:2724 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 Last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:347 __call_rcu kernel/rcu/tree.c:2966 [inline] call_rcu+0xbb/0x700 kernel/rcu/tree.c:3039 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Second to last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:347 __call_rcu kernel/rcu/tree.c:2966 [inline] call_rcu+0xbb/0x700 kernel/rcu/tree.c:3039 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88801b988780 which belongs to the cache filp of size 464 The buggy address is located 303 bytes inside of 464-byte region [ffff88801b988780, ffff88801b988950) The buggy address belongs to the page: page:000000004f357a26 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b988 head:000000004f357a26 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 ffffea000046c200 0000000400000004 ffff8880101c2640 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801b988780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b988800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b988880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b988900: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff88801b988980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================