bisecting fixing commit since 78d697fc93f98054e36a3ab76dca1a88802ba7be
building syzkaller on 2e9971bbbfb4df6ba0118353163a7703f3dbd6ec
testing commit 78d697fc93f98054e36a3ab76dca1a88802ba7be with gcc (GCC) 8.1.0
kernel signature: 42a5580928d906670a757f6ecf222bc3513b918d306db29afe4a5d827dc5ce0b
all runs: crashed: KASAN: stack-out-of-bounds Read in nft_range_dump
testing current HEAD 4520f06b03ae667e442da1ab9351fd28cd7ac598
testing commit 4520f06b03ae667e442da1ab9351fd28cd7ac598 with gcc (GCC) 8.1.0
kernel signature: 140484daf6a85e81a7b8a6b4bffab0f836984c9eb477fe3c7c4477648a946e84
all runs: crashed: KASAN: stack-out-of-bounds Read in nft_range_dump
revisions tested: 2, total time: 23m18.254618484s (build: 16m37.221595429s, test: 5m59.237136278s)
the crash still happens on HEAD
commit msg: Linux 4.14.175
crash: KASAN: stack-out-of-bounds Read in nft_range_dump
IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
==================================================================
IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready
BUG: KASAN: stack-out-of-bounds in nft_range_dump+0x1a6/0x1d0 net/netfilter/nft_range.c:115
Read of size 1 at addr ffff888088ee7100 by task syz-executor.1/7771
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready

CPU: 1 PID: 7771 Comm: syz-executor.1 Not tainted 4.14.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 print_address_description.cold.7+0x9/0x1c9 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.8+0x11a/0x2d3 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 nft_range_dump+0x1a6/0x1d0 net/netfilter/nft_range.c:115
 nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline]
 nfnetlink_parse_nat_setup+0x1e6/0x320 net/netfilter/nf_nat_core.c:784
 ctnetlink_parse_nat_setup+0x61/0x3d0 net/netfilter/nf_conntrack_netlink.c:1421
 ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1496 [inline]
 ctnetlink_create_conntrack+0x39b/0xf10 net/netfilter/nf_conntrack_netlink.c:1840
 ctnetlink_new_conntrack+0x432/0xd30 net/netfilter/nf_conntrack_netlink.c:1964
 nfnetlink_rcv_msg+0x89a/0xa70 net/netfilter/nfnetlink.c:214
 netlink_rcv_skb+0x133/0x370 net/netlink/af_netlink.c:2433
 nfnetlink_rcv+0x176/0x1570 net/netfilter/nfnetlink.c:515
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x600 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x730/0xbd0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:656
 ___sys_sendmsg+0x625/0x920 net/socket.c:2062
 __sys_sendmsg+0xc1/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0xd/0x20 net/socket.c:2103
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c4a9
RSP: 002b:00007fce657dac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fce657db6d4 RCX: 000000000045c4a9
RDX: 0000000000000000 RSI: 0000000020000640 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000959 R14: 00000000004cbd25 R15: 000000000076bf2c

The buggy address belongs to the page:
page:ffffea000223b9c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0xfffe0000000000()
raw: 00fffe0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888088ee7000: 00 00 f1 f1 f1 f1 04 f2 f2 f2 f3 f3 f3 f3 00 00
 ffff888088ee7080: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00
>ffff888088ee7100: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 f2 f2 f3
                   ^
 ffff888088ee7180: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888088ee7200: 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2
==================================================================
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!