kernel BUG at mm/slab.c:LINE!

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 7d80e121 Linux 4.14.136
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13fa6542600000
kernel config: https://syzkaller.appspot.com/x/.config?x=4ca439d79e42214b
dashboard link: https://syzkaller.appspot.com/bug?extid=e6da2cd96b04be255a89
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17c7f2fc600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13563aaa600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e6da2c...@syzkaller.appspotmail.com

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
audit: type=1400 audit(1564929772.706:36): avc: denied { map } for
pid=7130 comm="syz-executor271" path="/root/syz-executor271789419"
dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
------------[ cut here ]------------
kernel BUG at mm/slab.c:4427!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7130 Comm: syz-executor271 Not tainted 4.14.136 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff888092d00200 task.stack: ffff88809ddb0000
RIP: 0010:__check_heap_object+0x58/0x5a mm/slab.c:4427
RSP: 0018:ffff88809ddb7bc0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: 00000000000003a3 RCX: 0000000000000015
RDX: 00000000003fdf7b RSI: 00000000000003a3 RDI: ffff8880813ffff3
RBP: ffff88809ddb7c00 R08: ffff8880aa802c80 R09: ffff888081000080
R10: ffff88821fff8050 R11: 0000000000000001 R12: ffff8880813ffff3
R13: ffffea0002040000 R14: 0000000000000001 R15: ffffea0002040000
FS: 0000000002077880(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556eab6bd1b0 CR3: 00000000a7fb6000 CR4: 00000000001406e0
Call Trace:
check_object_size include/linux/thread_info.h:108 [inline]
check_copy_size include/linux/thread_info.h:139 [inline]
copy_to_user include/linux/uaccess.h:154 [inline]
bpf_test_finish.isra.0+0x9a/0x150 net/bpf/test_run.c:59
bpf_prog_test_run_skb+0x5af/0x9a0 net/bpf/test_run.c:144
bpf_prog_test_run kernel/bpf/syscall.c:1258 [inline]
SYSC_bpf kernel/bpf/syscall.c:1520 [inline]
SyS_bpf+0x749/0x38f3 kernel/bpf/syscall.c:1469
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x440379
RSP: 002b:00007ffc110b0c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440379
RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401c00
R13: 0000000000401c90 R14: 0000000000000000 R15: 0000000000000000
Code: e8 41 39 40 24 76 24 41 0f af 40 14 4c 01 c8 48 29 c7 49 63 40 74 48
39 f8 72 08 48 29 f8 48 39 f0 73 05 49 8b 40 58 c3 31 c0 c3 <0f> 0b 44 89
e9 48 c7 c7 70 cf 41 87 89 75 d4 4c 8d 45 cc 81 e1
RIP: __check_heap_object+0x58/0x5a mm/slab.c:4427 RSP: ffff88809ddb7bc0
---[ end trace ca535ca8d21adb4d ]---


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