netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. ================================================================== BUG: KASAN: use-after-free in sctp_association_free+0x7b7/0x930 net/sctp/associola.c:333 Read of size 8 at addr ffff8801d8a8aa20 by task syz-executor0/28066 CPU: 1 PID: 28066 Comm: syz-executor0 Not tainted 4.14.0-rc5+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 sctp_association_free+0x7b7/0x930 net/sctp/associola.c:333 sctp_sendmsg+0x1845/0x32b0 net/sctp/socket.c:2019 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x452719 RSP: 002b:00007f4c6025fbe8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452719 RDX: 0000000000000071 RSI: 0000000020bf8f8f RDI: 0000000000000013 RBP: 000000000000051f R08: 0000000020f87000 R09: 000000000000001c R10: 0000000020000000 R11: 0000000000000212 R12: 00000000006f5b88 R13: 00000000ffffffff R14: 00007f4c602606d4 R15: 0000000000000012 Allocated by task 28066: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:666 [inline] sctp_association_new+0x114/0x21e0 net/sctp/associola.c:309 sctp_sendmsg+0x1c89/0x32b0 net/sctp/socket.c:1839 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 28066: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 sctp_association_destroy net/sctp/associola.c:435 [inline] sctp_association_put+0x21c/0x2f0 net/sctp/associola.c:884 sctp_wait_for_sndbuf+0x5e3/0x7c0 net/sctp/socket.c:8003 sctp_sendmsg+0x2906/0x32b0 net/sctp/socket.c:1943 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801d8a8aa00 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 32 bytes inside of 4096-byte region [ffff8801d8a8aa00, ffff8801d8a8ba00) The buggy address belongs to the page: page:ffffea000762a280 count:1 mapcount:0 mapping:ffff8801d8a8aa00 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801d8a8aa00 0000000000000000 0000000100000001 raw: ffffea00069be5a0 ffffea0007204220 ffff8801dac00dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d8a8a900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d8a8a980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d8a8aa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d8a8aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d8a8ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================