================================================================== BUG: KASAN: slab-out-of-bounds in strnlen+0xc1/0xd0 lib/string.c:498 Read of size 1 at addr ffff8800b651a49e by task syz-executor1/5361 CPU: 0 PID: 5361 Comm: syz-executor1 Not tainted 4.4.113-ge70c132 #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 58179d3d40c76865 ffff8801d2b4f580 ffffffff81d0278d ffffea0002d94680 ffff8800b651a49e 0000000000000000 ffff8800b651a49e ffff8801d2b4f850 ffff8801d2b4f5b8 ffffffff814fd053 ffff8800b651a49e Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x73/0x260 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x285/0x370 mm/kasan/report.c:408 [] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426 [] strnlen+0xc1/0xd0 lib/string.c:498 [] string.isra.4+0x4c/0x240 lib/vsprintf.c:518 [] vsnprintf+0x766/0x15f0 lib/vsprintf.c:1907 capability: warning: `syz-executor3' uses 32-bit capabilities (legacy support in use) [] __request_module+0x14f/0x810 kernel/kmod.c:146 [] xt_request_find_target+0x8b/0xb0 net/netfilter/x_tables.c:255 [] check_compat_entry_size_and_hooks net/ipv4/netfilter/ip_tables.c:1490 [inline] [] translate_compat_table+0x568/0x1760 net/ipv4/netfilter/ip_tables.c:1582 [] ? 0xffffffff810002b8 [] compat_do_replace.isra.15+0x1f1/0x410 net/ipv4/netfilter/ip_tables.c:1690 [] compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1721 [] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline] [] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:155 [] compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1255 [] inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:914 [] compat_tcp_setsockopt+0x3d/0x70 net/ipv4/tcp.c:2643 [] compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2670 [] C_SYSC_setsockopt net/compat.c:384 [inline] [] compat_SyS_setsockopt+0x149/0x290 net/compat.c:367 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 5361: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [] __kmalloc+0x124/0x320 mm/slub.c:3613 [] kmalloc include/linux/slab.h:481 [inline] [] xt_alloc_table_info+0x71/0x100 net/netfilter/x_tables.c:911 [] compat_do_replace.isra.15+0x16b/0x410 net/ipv4/netfilter/ip_tables.c:1679 [] compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1721 [] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline] [] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:155 [] compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1255 [] inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:914 [] compat_tcp_setsockopt+0x3d/0x70 net/ipv4/tcp.c:2643 [] compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2670 [] C_SYSC_setsockopt net/compat.c:384 [inline] [] compat_SyS_setsockopt+0x149/0x290 net/compat.c:367 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Freed by task 3207: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kfree+0xfc/0x300 mm/slub.c:3749 [] inode_doinit_with_dentry+0xa05/0x1b80 security/selinux/hooks.c:1416 [] selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:5591 [] security_d_instantiate+0x5a/0xe0 security/security.c:1120 [] d_splice_alias+0x17b/0x680 fs/dcache.c:2852 [] ext4_lookup+0x2d2/0x3f0 fs/ext4/namei.c:1621 [] lookup_real+0x98/0x100 fs/namei.c:1519 [] lookup_open fs/namei.c:3000 [inline] [] do_last fs/namei.c:3110 [inline] [] path_openat+0x21a1/0x3940 fs/namei.c:3353 [] do_filp_open+0x197/0x290 fs/namei.c:3388 [] do_sys_open+0x343/0x4b0 fs/open.c:1038 [] SYSC_open fs/open.c:1056 [inline] [] SyS_open+0x2d/0x40 fs/open.c:1051 [] entry_SYSCALL_64_fastpath+0x1c/0x98 The buggy address belongs to the object at ffff8800b651a3c0 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 222 bytes inside of 256-byte region [ffff8800b651a3c0, ffff8800b651a4c0) The buggy address belongs to the page: