netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'. ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline] BUG: KASAN: slab-out-of-bounds in dh_pack_data crypto/dh_helper.c:21 [inline] BUG: KASAN: slab-out-of-bounds in crypto_dh_encode_key+0x80e/0x830 crypto/dh_helper.c:60 Write of size 4 at addr ffff8801d70aeed0 by task syz-executor4/27620 CPU: 1 PID: 27620 Comm: syz-executor4 Not tainted 4.18.0-rc7-next-20180803+ #31 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+0x1c9/0x2b4 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+0x242/0x30d mm/kasan/report.c:412 __asan_report_store_n_noabort+0x12/0x14 mm/kasan/report.c:449 memcpy include/linux/string.h:345 [inline] dh_pack_data crypto/dh_helper.c:21 [inline] crypto_dh_encode_key+0x80e/0x830 crypto/dh_helper.c:60 __keyctl_dh_compute+0x707/0x1c00 security/keys/dh.c:316 9pnet: p9_fd_create_unix (27634): problem connecting socket: ./file0/file0: -2 keyctl_dh_compute+0xc5/0x11f security/keys/dh.c:427 __do_sys_keyctl security/keys/keyctl.c:1741 [inline] __se_sys_keyctl security/keys/keyctl.c:1637 [inline] __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456b29 Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd81cd2ac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000fa RAX: ffffffffffffffda RBX: 00007fd81cd2b6d4 RCX: 0000000000456b29 RDX: 0000000020000180 RSI: 0000000020000140 RDI: 0000000000000017 RBP: 00000000009300a0 R08: 00000000200002c0 R09: 0000000000000000 R10: 00000000000000c3 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d16a0 R14: 00000000004c7069 R15: 0000000000000000 Allocated by task 27620: 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 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] __keyctl_dh_compute+0x6e1/0x1c00 security/keys/dh.c:311 keyctl_dh_compute+0xc5/0x11f security/keys/dh.c:427 __do_sys_keyctl security/keys/keyctl.c:1741 [inline] __se_sys_keyctl security/keys/keyctl.c:1637 [inline] __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4353: 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] kfree+0xd9/0x260 mm/slab.c:3813 kvfree+0x61/0x70 mm/util.c:449 __vunmap+0x326/0x460 mm/vmalloc.c:1529 vfree+0x68/0x100 mm/vmalloc.c:1593 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:870 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1027 [inline] do_ipt_get_ctl+0xa1f/0xc00 net/ipv4/netfilter/ip_tables.c:1703 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline] nf_getsockopt+0x80/0xe0 net/netfilter/nf_sockopt.c:122 ip_getsockopt+0x1fb/0x2b0 net/ipv4/ip_sockglue.c:1577 tcp_getsockopt+0x93/0xe0 net/ipv4/tcp.c:3584 sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:3042 __sys_getsockopt+0x1ad/0x390 net/socket.c:1938 __do_sys_getsockopt net/socket.c:1949 [inline] __se_sys_getsockopt net/socket.c:1946 [inline] __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1946 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801d70aeec0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 16 bytes inside of 32-byte region [ffff8801d70aeec0, ffff8801d70aeee0) The buggy address belongs to the page: page:ffffea00075c2b80 count:1 mapcount:0 mapping:ffff8801dac001c0 index:0xffff8801d70aefc1 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00074d1f48 ffffea0006482c88 ffff8801dac001c0 raw: ffff8801d70aefc1 ffff8801d70ae000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d70aed80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d70aee00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d70aee80: fb fb fb fb fc fc fc fc 00 00 03 fc fc fc fc fc ^ ffff8801d70aef00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d70aef80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================