bisecting fixing commit since 78d697fc93f98054e36a3ab76dca1a88802ba7be building syzkaller on 2e9971bbbfb4df6ba0118353163a7703f3dbd6ec testing commit 78d697fc93f98054e36a3ab76dca1a88802ba7be with gcc (GCC) 8.1.0 kernel signature: 78ea31a9b3df1879962e70097e8de265264d76714e434736ad0c57985d1257b6 all runs: crashed: KASAN: stack-out-of-bounds Read in nft_range_dump testing current HEAD c6db52a88798e5a0dfef80041ad4d33cc8cf04eb testing commit c6db52a88798e5a0dfef80041ad4d33cc8cf04eb with gcc (GCC) 8.1.0 kernel signature: 2960bd4add2e56d16eab0d5cb6506a3ff41e0b2d33c9312031f32e8513922b3e all runs: crashed: KASAN: stack-out-of-bounds Read in nft_range_dump revisions tested: 2, total time: 23m47.283269105s (build: 17m7.985460175s, test: 6m6.256921812s) the crash still happens on HEAD commit msg: Linux 4.14.183 crash: KASAN: stack-out-of-bounds Read in nft_range_dump IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready ================================================================== BUG: KASAN: stack-out-of-bounds in nft_range_dump+0x1a6/0x1d0 net/netfilter/nft_range.c:115 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 Read of size 1 at addr ffff8880a8147100 by task syz-executor.2/7755 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! CPU: 0 PID: 7755 Comm: syz-executor.2 Not tainted 4.14.183-syzkaller #0 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! 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 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline] nfnetlink_parse_nat_setup+0x1e6/0x320 net/netfilter/nf_nat_core.c:784 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_0 ctnetlink_parse_nat_setup+0x61/0x3d0 net/netfilter/nf_conntrack_netlink.c:1421 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1496 [inline] ctnetlink_create_conntrack+0x39b/0xf10 net/netfilter/nf_conntrack_netlink.c:1840 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! ctnetlink_new_conntrack+0x432/0xd30 net/netfilter/nf_conntrack_netlink.c:1964 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 nfnetlink_rcv_msg+0x89a/0xa70 net/netfilter/nfnetlink.c:214 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! netlink_rcv_skb+0x133/0x370 net/netlink/af_netlink.c:2433 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 nfnetlink_rcv+0x176/0x1570 net/netfilter/nfnetlink.c:515 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 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+0x46/0xbb RIP: 0033:0x45c4a9 RSP: 002b:00007f40321a5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f40321a66d4 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:ffffea0002a051c0 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: ffff8880a8147000: 00 00 f1 f1 f1 f1 04 f2 f2 f2 f3 f3 f3 f3 00 00 ffff8880a8147080: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 >ffff8880a8147100: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 f2 f2 f3 ^ ffff8880a8147180: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a8147200: 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2 ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready