random: sshd: uninitialized urandom read (32 bytes read, 96 bits of entropy available)
==================================================================
BUG: KASAN: slab-out-of-bounds in strnlen+0xc1/0xd0 lib/string.c:498
Read of size 1 at addr ffff8801d1dfd490 by task syzkaller419834/3310

CPU: 1 PID: 3310 Comm: syzkaller419834 Not tainted 4.4.113-ge70c132 #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 3a0086785c7834f7 ffff8800b49ef5c0 ffffffff81d0278d
 ffffea0007477f40 ffff8801d1dfd490 0000000000000000 ffff8801d1dfd490
 ffff8800b49ef890 ffff8800b49ef5f8 ffffffff814fd053 ffff8801d1dfd490
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
 [<ffffffff8326a258>] check_compat_entry_size_and_hooks net/ipv4/netfilter/ip_tables.c:1490 [inline]
 [<ffffffff8326a258>] translate_compat_table+0x568/0x1760 net/ipv4/netfilter/ip_tables.c:1582
 [<ffffffff810002b8>] ? 0xffffffff810002b8
 [<ffffffff8326b641>] compat_do_replace.isra.15+0x1f1/0x410 net/ipv4/netfilter/ip_tables.c:1690
 [<ffffffff8326b966>] compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1721
 [<ffffffff82f94e58>] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline]
 [<ffffffff82f94e58>] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:155
 [<ffffffff830fc26d>] compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1255
 [<ffffffff831a1ed5>] compat_udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2164
 [<ffffffff82df0732>] compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2670
 [<ffffffff82ed7659>] C_SYSC_setsockopt net/compat.c:384 [inline]
 [<ffffffff82ed7659>] compat_SyS_setsockopt+0x149/0x290 net/compat.c:367
 [<ffffffff81006d74>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d74>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff837734ea>] sysenter_flags_fixed+0xd/0x17

Allocated by task 3310:
 [<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
 [<ffffffff8326b5bb>] compat_do_replace.isra.15+0x16b/0x410 net/ipv4/netfilter/ip_tables.c:1679
 [<ffffffff8326b966>] compat_do_ipt_set_ctl+0x106/0x150 net/ipv4/netfilter/ip_tables.c:1721
 [<ffffffff82f94e58>] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline]
 [<ffffffff82f94e58>] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:155
 [<ffffffff830fc26d>] compat_ip_setsockopt+0x9d/0xf0 net/ipv4/ip_sockglue.c:1255
 [<ffffffff831a1ed5>] compat_udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2164
 [<ffffffff82df0732>] compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2670
 [<ffffffff82ed7659>] C_SYSC_setsockopt net/compat.c:384 [inline]
 [<ffffffff82ed7659>] compat_SyS_setsockopt+0x149/0x290 net/compat.c:367
 [<ffffffff81006d74>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d74>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff837734ea>] sysenter_flags_fixed+0xd/0x17

Freed by task 1768:
 [<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 ffff8801d1dfd3c0
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 208 bytes inside of
 256-byte region [ffff8801d1dfd3c0, ffff8801d1dfd4c0)
The buggy address belongs to the page:
page:ffffea0007477f40 count:1 mapcount:-2146697203 mapping:          (null) index:0x0
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.113-ge70c132 #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84217840 task.stack: ffffffff84200000
RIP: 0010:[<ffffffff81d13a00>]  [<ffffffff81d13a00>] __rb_change_child include/linux/rbtree_augmented.h:125 [inline]
RIP: 0010:[<ffffffff81d13a00>]  [<ffffffff81d13a00>] __rb_rotate_set_parents lib/rbtree.c:93 [inline]
RIP: 0010:[<ffffffff81d13a00>]  [<ffffffff81d13a00>] __rb_insert lib/rbtree.c:181 [inline]
RIP: 0010:[<ffffffff81d13a00>]  [<ffffffff81d13a00>] rb_insert_color+0x1d0/0xcb0 lib/rbtree.c:420
RSP: 0018:ffff8801db207d18  EFLAGS: 00010806
RAX: ffff8801db219c40 RBX: ffffea0007477f40 RCX: 1000000000000012
RDX: dffffc0000000000 RSI: ffff8801db219710 RDI: ffffea0007477f50
RBP: ffff8801db207d60 R08: ffffffff8580af08 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff1003b640f62 R12: 8000000000000090
R13: 8000000000000080 R14: 8000000000000080 R15: ffff8801db219c48
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557db83100 CR3: 00000000b5b2a000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff842bdb20 ffffffff842180b0 0000000000000000 ffff8801db207d70
 ffff8801db219c40 dffffc0000000000 0000000000000000 ffff8801db219710
 ffff8800b4887e00 ffff8801db207db0 ffffffff81d20067 ffff8801db219c58
Call Trace:
 <IRQ> 
 [<ffffffff81d20067>] timerqueue_add+0x157/0x2a0 lib/timerqueue.c:57
 [<ffffffff812aabb8>] enqueue_hrtimer+0x168/0x450 kernel/time/hrtimer.c:890
 [<ffffffff812acc42>] __run_hrtimer kernel/time/hrtimer.c:1268 [inline]
 [<ffffffff812acc42>] __hrtimer_run_queues+0x732/0xfe0 kernel/time/hrtimer.c:1317
 [<ffffffff812aece6>] hrtimer_interrupt+0x1a6/0x440 kernel/time/hrtimer.c:1351
 [<ffffffff810b0c7a>] local_apic_timer_interrupt+0x6a/0xb0 arch/x86/kernel/apic/apic.c:901
 [<ffffffff837747b6>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:925
 [<ffffffff83773710>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:737
 <EOI> 
 [<ffffffff81027ed5>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline]
 [<ffffffff81027ed5>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291
 [<ffffffff8102945a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282
 [<ffffffff81220418>] default_idle_call+0x48/0x70 kernel/sched/idle.c:93
 [<ffffffff81220b1d>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff81220b1d>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff81220b1d>] cpu_startup_entry+0x5fd/0x8f0 kernel/sched/idle.c:301
 [<ffffffff8375ead9>] rest_init+0x189/0x190 init/main.c:410
 [<ffffffff84821811>] start_kernel+0x6b9/0x6ee init/main.c:682
 [<ffffffff84820312>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196
 [<ffffffff84820454>] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185
Code: 48 c1 e9 03 80 3c 11 00 0f 85 83 06 00 00 4d 85 ed 48 89 03 74 5b 4d 8d 65 10 48 ba 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 <80> 3c 11 00 0f 85 19 07 00 00 49 3b 5d 10 0f 84 eb 04 00 00 49 
RIP  [<ffffffff81d13a00>] __rb_change_child include/linux/rbtree_augmented.h:125 [inline]
RIP  [<ffffffff81d13a00>] __rb_rotate_set_parents lib/rbtree.c:93 [inline]
RIP  [<ffffffff81d13a00>] __rb_insert lib/rbtree.c:181 [inline]
RIP  [<ffffffff81d13a00>] rb_insert_color+0x1d0/0xcb0 lib/rbtree.c:420
 RSP <ffff8801db207d18>
---[ end trace 8947dbf9570c1c35 ]---