RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000015 R13: 000000000000071e R14: 00000000006feb70 R15: 0000000000000007 ================================================================== BUG: KASAN: use-after-free in sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1817 [inline] BUG: KASAN: use-after-free in sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] BUG: KASAN: use-after-free in sctp_do_sm+0x6015/0x7160 net/sctp/sm_sideeffect.c:1191 Read of size 1 at addr ffff8801c7883cb8 by task syz-executor6/18616 CPU: 1 PID: 18616 Comm: syz-executor6 Not tainted 4.17.0-rc4+ #38 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1817 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] sctp_do_sm+0x6015/0x7160 net/sctp/sm_sideeffect.c:1191 sctp_assoc_bh_rcv+0x30f/0x520 net/sctp/associola.c:1065 sctp_inq_push+0x263/0x320 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x192/0xc00 net/sctp/input.c:350 sk_backlog_rcv include/net/sock.h:909 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2335 release_sock+0xa4/0x2b0 net/core/sock.c:2850 sctp_sendmsg+0x13cc/0x1d70 net/sctp/socket.c:2128 inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 sock_write_iter+0x35a/0x5a0 net/socket.c:908 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f6fad842c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6fad8436d4 RCX: 0000000000455979 RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000015 R13: 000000000000071e R14: 00000000006feb70 R15: 0000000000000007 Allocated by task 18616: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:691 [inline] sctp_chunkify+0xce/0x400 net/sctp/sm_make_chunk.c:1355 sctp_rcv+0xc65/0x3a60 net/sctp/input.c:221 sctp6_rcv+0x15/0x30 net/sctp/ipv6.c:1045 ip6_input_finish+0x3ff/0x1a30 net/ipv6/ip6_input.c:284 NF_HOOK include/linux/netfilter.h:288 [inline] ip6_input+0xe1/0x5e0 net/ipv6/ip6_input.c:327 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x29c/0xa10 net/ipv6/ip6_input.c:71 NF_HOOK include/linux/netfilter.h:288 [inline] ipv6_rcv+0xed6/0x22a0 net/ipv6/ip6_input.c:208 __netif_receive_skb_core+0x26f5/0x3630 net/core/dev.c:4592 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4657 process_backlog+0x219/0x760 net/core/dev.c:5337 napi_poll net/core/dev.c:5735 [inline] net_rx_action+0x7b7/0x1930 net/core/dev.c:5801 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 Freed by task 18616: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 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+0x86/0x2d0 mm/slab.c:3756 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1481 [inline] sctp_chunk_put+0x321/0x440 net/sctp/sm_make_chunk.c:1504 sctp_ulpevent_make_rcvmsg+0x955/0xd40 net/sctp/ulpevent.c:718 sctp_ulpq_tail_data+0xa8/0x12b0 net/sctp/ulpqueue.c:108 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1478 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] sctp_do_sm+0x1658/0x7160 net/sctp/sm_sideeffect.c:1191 sctp_assoc_bh_rcv+0x30f/0x520 net/sctp/associola.c:1065 sctp_inq_push+0x263/0x320 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x192/0xc00 net/sctp/input.c:350 sk_backlog_rcv include/net/sock.h:909 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2335 release_sock+0xa4/0x2b0 net/core/sock.c:2850 sctp_sendmsg+0x13cc/0x1d70 net/sctp/socket.c:2128 inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 sock_write_iter+0x35a/0x5a0 net/socket.c:908 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801c7883bc0 which belongs to the cache sctp_chunk of size 256 The buggy address is located 248 bytes inside of 256-byte region [ffff8801c7883bc0, ffff8801c7883cc0) The buggy address belongs to the page: page:ffffea00071e20c0 count:1 mapcount:0 mapping:ffff8801c7883080 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801c7883080 0000000000000000 000000010000000c raw: ffffea000723a220 ffff8801cdb66f48 ffff8801cdb65600 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c7883b80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801c7883c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c7883c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801c7883d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c7883d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================