================================================================== BUG: KASAN: slab-out-of-bounds in string+0x1e8/0x200 lib/vsprintf.c:595 Read of size 1 at addr ffff8801d0019463 by task syz-executor4/6433 CPU: 1 PID: 6433 Comm: syz-executor4 Not tainted 4.15.0-rc9+ #193 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 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_load1_noabort+0x14/0x20 mm/kasan/report.c:427 string+0x1e8/0x200 lib/vsprintf.c:595 vsnprintf+0x863/0x1900 lib/vsprintf.c:2282 __request_module+0x1bf/0xc20 kernel/kmod.c:143 xt_request_find_target+0x8b/0xb0 net/netfilter/x_tables.c:257 check_compat_entry_size_and_hooks net/ipv4/netfilter/ip_tables.c:1339 [inline] translate_compat_table+0x910/0x1b90 net/ipv4/netfilter/ip_tables.c:1426 compat_do_replace.isra.15+0x30e/0x720 net/ipv4/netfilter/ip_tables.c:1529 compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1558 compat_nf_sockopt net/netfilter/nf_sockopt.c:144 [inline] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:156 compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1285 inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:1042 compat_tcp_setsockopt+0x3d/0x70 net/ipv4/tcp.c:2886 compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2979 C_SYSC_setsockopt net/compat.c:403 [inline] compat_SyS_setsockopt+0x17c/0x410 net/compat.c:386 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 RIP: 0023:0xf7f0bc79 RSP: 002b:00000000f770708c EFLAGS: 00000296 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000000000 RDX: 0000000000000040 RSI: 0000000020423000 RDI: 000000000000013f RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6433: 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 __do_kmalloc_node mm/slab.c:3672 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3679 kmalloc_node include/linux/slab.h:541 [inline] kvmalloc_node+0x99/0xd0 mm/util.c:397 kvmalloc include/linux/mm.h:541 [inline] xt_alloc_table_info+0x64/0xe0 net/netfilter/x_tables.c:1006 compat_do_replace.isra.15+0x17f/0x720 net/ipv4/netfilter/ip_tables.c:1518 compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1558 compat_nf_sockopt net/netfilter/nf_sockopt.c:144 [inline] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:156 compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1285 inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:1042 compat_tcp_setsockopt+0x3d/0x70 net/ipv4/tcp.c:2886 compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2979 C_SYSC_setsockopt net/compat.c:403 [inline] compat_SyS_setsockopt+0x17c/0x410 net/compat.c:386 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 Freed by task 3000: 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:3488 [inline] kfree+0xd6/0x260 mm/slab.c:3803 skb_free_head+0x74/0xb0 net/core/skbuff.c:550 skb_release_data+0x58c/0x790 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0x153/0x490 net/core/skbuff.c:701 netlink_broadcast_filtered+0x5d0/0x1360 net/netlink/af_netlink.c:1477 netlink_broadcast net/netlink/af_netlink.c:1499 [inline] nlmsg_multicast include/net/netlink.h:591 [inline] nlmsg_notify+0x91/0x150 net/netlink/af_netlink.c:2452 rtnl_notify+0xbb/0xe0 net/core/rtnetlink.c:649 inet6_ifa_notify net/ipv6/addrconf.c:4982 [inline] __ipv6_ifa_notify+0x44c/0xa90 net/ipv6/addrconf.c:5531 ipv6_ifa_notify+0xd9/0x1c0 net/ipv6/addrconf.c:5575 inet6_addr_modify net/ipv6/addrconf.c:4507 [inline] inet6_rtm_newaddr+0xabe/0xcd0 net/ipv6/addrconf.c:4598 rtnetlink_rcv_msg+0x733/0x1020 net/core/rtnetlink.c:4411 netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2409 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4423 netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline] netlink_unicast+0x4ee/0x700 net/netlink/af_netlink.c:1301 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1864 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2028 __sys_sendmsg+0xe5/0x210 net/socket.c:2062 C_SYSC_sendmsg net/compat.c:739 [inline] compat_SyS_sendmsg+0x2a/0x40 net/compat.c:737 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 The buggy address belongs to the object at ffff8801d0019340 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 291 bytes inside of 512-byte region [ffff8801d0019340, ffff8801d0019540) The buggy address belongs to the page: page:ffffea0007400640 count:1 mapcount:0 mapping:ffff8801d00190c0 index:0xffff8801d00195c0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d00190c0 ffff8801d00195c0 0000000100000004 raw: ffffea00074070e0 ffffea00072cb6e0 ffff8801dac00940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d0019300: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8801d0019380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8801d0019400: 00 00 00 00 00 00 00 00 00 00 00 00 03 fc fc fc ^ ffff8801d0019480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d0019500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================