general protection fault in af_alg_free_areq_sgls

syzkaller has found reproducer for the following crash on 3c1c4ddffb58b9e10b3365764fe59546130b3f32
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3084 Comm: syzkaller426369 Not tainted 4.15.0-rc1+ #203
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: 000000009887e938 task.stack: 00000000ae5f34d5
RIP: 0010:compound_head include/linux/page-flags.h:147 [inline]
RIP: 0010:put_page include/linux/mm.h:850 [inline]
RIP: 0010:af_alg_free_areq_sgls+0x5d1/0xab0 crypto/af_alg.c:678
RSP: 0018:ffff8801cc2d7790 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff8239cc1a
RDX: 0000000000000000 RSI: ffffffff85f44540 RDI: 0000000000000000
RBP: ffff8801cc2d7988 R08: 1ffff1003985ae76 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 00000000fffffff4 R15: ffffed003985af24
FS:  00000000021ae940(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020233fd0 CR3: 00000001cb97b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 af_alg_free_resources+0x36/0x80 crypto/af_alg.c:1030
 _aead_recvmsg crypto/algif_aead.c:316 [inline]
 aead_recvmsg+0x14e1/0x1bc0 crypto/algif_aead.c:329
 sock_recvmsg_nosec net/socket.c:805 [inline]
 sock_recvmsg+0xc9/0x110 net/socket.c:812
 ___sys_recvmsg+0x29b/0x630 net/socket.c:2207
 __sys_recvmsg+0xe2/0x210 net/socket.c:2252
 SYSC_recvmsg net/socket.c:2264 [inline]
 SyS_recvmsg+0x2d/0x50 net/socket.c:2259
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x440f09
RSP: 002b:00007fff6ddf3098 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000440f09
RDX: 0000000000000000 RSI: 00000000209c6fc8 RDI: 0000000000000004
RBP: 0000000000000005 R08: 0000000000000001 R09: 00000000021a0032
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402830
R13: 00000000004028c0 R14: 0000000000000000 R15: 0000000000000000
Code: 00 00 48 8d 45 98 48 bb 00 00 00 00 00 fc ff df 48 89 85 48 fe ff ff 48 c1 e8 03 4c 8d 3c 18 e8 16 2c 36 ff 4c 89 e0 48 c1 e8 03 <80> 3c 18 00 0f 85 4b 03 00 00 49 8b 04 24 48 83 e0 fc 48 89 85
RIP: compound_head include/linux/page-flags.h:147 [inline] RSP: ffff8801cc2d7790
RIP: put_page include/linux/mm.h:850 [inline] RSP: ffff8801cc2d7790
RIP: af_alg_free_areq_sgls+0x5d1/0xab0 crypto/af_alg.c:678 RSP: ffff8801cc2d7790
---[ end trace de1b188df438eb0f ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..