================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x8f/0xac lib/list_debug.c:26 Read of size 8 at addr ffff8881ccdb6b70 by task syz-executor1/24447 CPU: 1 PID: 24447 Comm: syz-executor1 Not tainted 4.20.0-rc6-next-20181210+ #164 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.4+0x9/0x1ff mm/kasan/report.c:187 kasan_report.cold.5+0x1b/0x39 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 __list_add_valid+0x8f/0xac lib/list_debug.c:26 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] neigh_alloc net/core/neighbour.c:395 [inline] ___neigh_create+0x14b7/0x2600 net/core/neighbour.c:553 __neigh_create+0x30/0x40 net/core/neighbour.c:640 ip_finish_output2+0xb91/0x1a30 net/ipv4/ip_output.c:224 ip_finish_output+0x7fd/0xfa0 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_mc_output+0x2c4/0x15b0 net/ipv4/ip_output.c:390 dst_output include/net/dst.h:444 [inline] ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124 __ip_queue_xmit+0x9af/0x1f40 net/ipv4/ip_output.c:505 sctp_v4_xmit+0x1a7/0x200 net/sctp/protocol.c:991 sctp_packet_transmit+0x1f1d/0x3d00 net/sctp/output.c:641 sctp_packet_singleton net/sctp/outqueue.c:787 [inline] sctp_outq_flush_ctrl.constprop.11+0x7a9/0xe50 net/sctp/outqueue.c:918 sctp_outq_flush+0x310/0x34f0 net/sctp/outqueue.c:1200 sctp_outq_uncork+0x6a/0x80 net/sctp/outqueue.c:772 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1820 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] sctp_do_sm+0x5ff/0x7190 net/sctp/sm_sideeffect.c:1191 sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:88 sctp_sendmsg_to_asoc+0x52a/0x1a10 net/sctp/socket.c:1923 sctp_sendmsg+0x13c2/0x1da0 net/sctp/socket.c:2113 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457659 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1f28a1ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457659 RDX: 0000000000000040 RSI: 0000000020003680 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f28a1f6d4 R13: 00000000004c43e5 R14: 00000000004d7370 R15: 00000000ffffffff Allocated by task 9190: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482 __do_kmalloc mm/slab.c:3709 [inline] __kmalloc+0x15d/0x760 mm/slab.c:3718 kmalloc_array include/linux/slab.h:668 [inline] kcalloc include/linux/slab.h:679 [inline] alloc_pipe_info+0x2ce/0x5d0 fs/pipe.c:650 get_pipe_inode fs/pipe.c:712 [inline] create_pipe_files+0x91/0x720 fs/pipe.c:744 __do_pipe_flags+0x45/0x250 fs/pipe.c:781 do_pipe2+0x9d/0x310 fs/pipe.c:829 __do_sys_pipe2 fs/pipe.c:847 [inline] __se_sys_pipe2 fs/pipe.c:845 [inline] __x64_sys_pipe2+0x54/0x80 fs/pipe.c:845 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9190: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kfree+0xcf/0x230 mm/slab.c:3804 free_pipe_info+0x24b/0x300 fs/pipe.c:683 put_pipe_info+0xd0/0xf0 fs/pipe.c:556 pipe_release+0x1de/0x270 fs/pipe.c:577 __fput+0x3bc/0xa90 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881ccdb6900 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 624 bytes inside of 1024-byte region [ffff8881ccdb6900, ffff8881ccdb6d00) The buggy address belongs to the page: page:ffffea0007336d80 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0007464188 ffffea000717cc88 ffff8881da800ac0 raw: 0000000000000000 ffff8881ccdb6000 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ccdb6a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ccdb6a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881ccdb6b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ccdb6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ccdb6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================