random: sshd: uninitialized urandom read (32 bytes read, 122 bits of entropy available)
==================================================================
BUG: KASAN: slab-out-of-bounds in strnlen+0xc1/0xd0 lib/string.c:498
Read of size 1 at addr ffff8801d0aca5d0 by task syzkaller724216/3311

CPU: 0 PID: 3311 Comm: syzkaller724216 Not tainted 4.4.113-ge70c132 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 e93aa0721bcd09ea ffff8801d080f718 ffffffff81d0278d
 ffffea000742b280 ffff8801d0aca5d0 0000000000000000 ffff8801d0aca5d0
 ffff8801d080f9e8 ffff8801d080f750 ffffffff814fd053 ffff8801d0aca5d0
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fd053>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fd565>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fd565>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814fd664>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81d1e171>] strnlen+0xc1/0xd0 lib/string.c:498
 [<ffffffff81d25dfc>] string.isra.4+0x4c/0x240 lib/vsprintf.c:518
 [<ffffffff81d2b2a6>] vsnprintf+0x766/0x15f0 lib/vsprintf.c:1907
 [<ffffffff8117160f>] __request_module+0x14f/0x810 kernel/kmod.c:146
 [<ffffffff8302c64b>] xt_request_find_target+0x8b/0xb0 net/netfilter/x_tables.c:255
 [<ffffffff832690d1>] find_check_entry net/ipv4/netfilter/ip_tables.c:685 [inline]
 [<ffffffff832690d1>] translate_table+0x12c1/0x1cf0 net/ipv4/netfilter/ip_tables.c:872
 [<ffffffff810002b8>] ? 0xffffffff810002b8
 [<ffffffff8326bc53>] do_replace net/ipv4/netfilter/ip_tables.c:1289 [inline]
 [<ffffffff8326bc53>] do_ipt_set_ctl+0x2a3/0x450 net/ipv4/netfilter/ip_tables.c:1852
 [<ffffffff82f94d77>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff82f94d77>] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff830fc1c1>] ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1226
 [<ffffffff831a2005>] udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2154
 [<ffffffff82df0645>] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2659
 [<ffffffff82ded730>] SYSC_setsockopt net/socket.c:1767 [inline]
 [<ffffffff82ded730>] SyS_setsockopt+0x160/0x250 net/socket.c:1746
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98

Allocated by task 3311:
 [<ffffffff81035df6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fc0c3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fc38d>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fc38d>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814f8674>] __kmalloc+0x124/0x320 mm/slub.c:3613
 [<ffffffff8302de91>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff8302de91>] xt_alloc_table_info+0x71/0x100 net/netfilter/x_tables.c:911
 [<ffffffff8326bbe2>] do_replace net/ipv4/netfilter/ip_tables.c:1278 [inline]
 [<ffffffff8326bbe2>] do_ipt_set_ctl+0x232/0x450 net/ipv4/netfilter/ip_tables.c:1852
 [<ffffffff82f94d77>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff82f94d77>] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff830fc1c1>] ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1226
 [<ffffffff831a2005>] udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2154
 [<ffffffff82df0645>] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2659
 [<ffffffff82ded730>] SYSC_setsockopt net/socket.c:1767 [inline]
 [<ffffffff82ded730>] SyS_setsockopt+0x160/0x250 net/socket.c:1746
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98

Freed by task 1794:
 [<ffffffff81035df6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fc0c3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fc9e2>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fc9e2>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814f947c>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814f947c>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814f947c>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814f947c>] kfree+0xfc/0x300 mm/slub.c:3749
 [<ffffffff8169860f>] kernfs_fop_release+0xff/0x140 fs/kernfs/file.c:737
 [<ffffffff81522363>] __fput+0x233/0x6d0 fs/file_table.c:208
 [<ffffffff81522885>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118b9d4>] task_work_run+0x104/0x180 kernel/task_work.c:115
 [<ffffffff8100361d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100361d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:251
 [<ffffffff81006535>] prepare_exit_to_usermode arch/x86/entry/common.c:282 [inline]
 [<ffffffff81006535>] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:347
 [<ffffffff83771ce9>] int_ret_from_sys_call+0x25/0xa3

The buggy address belongs to the object at ffff8801d0aca500
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 208 bytes inside of
 256-byte region [ffff8801d0aca500, ffff8801d0aca600)
The buggy address belongs to the page:
PANIC: double fault, error_code: 0x0
CPU: 0 PID: 3311 Comm: syzkaller724216 Not tainted 4.4.113-ge70c132 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b4444740 task.stack: ffff8801d0808000
RIP: 0010:[<ffffffff8135fc20>]  [<ffffffff8135fc20>] __sanitizer_cov_trace_pc+0x0/0x50
RSP: 0018:ffff880100000000  EFLAGS: 00010092
RAX: ffff8800b4444740 RBX: ffffea000742b280 RCX: ffffffff8148f8d0
RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea000742b280
RBP: ffff880100000038 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at kernel/locking/lockdep.c:3190 __lock_acquire+0x23b3/0x4b50 kernel/locking/lockdep.c:3190()
DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)