==================================================================
BUG: KASAN: use-after-free in crypto_aead_alg include/crypto/aead.h:198 [inline]
BUG: KASAN: use-after-free in crypto_aead_encrypt include/crypto/aead.h:330 [inline]
BUG: KASAN: use-after-free in _aead_recvmsg crypto/algif_aead.c:308 [inline]
BUG: KASAN: use-after-free in aead_recvmsg+0x1758/0x1bc0 crypto/algif_aead.c:329
Read of size 4 at addr ffff8801cc5fc3dc by task syzkaller944364/3095

CPU: 0 PID: 3095 Comm: syzkaller944364 Not tainted 4.15.0-rc1-mm1+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP:           (null)
PGD 1ccb84067 P4D 1ccb84067 PUD 1ccb5f067 PMD 0 
Oops: 0010 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3175 Comm: syzkaller944364 Not tainted 4.15.0-rc1-mm1+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: 00000000f38f58d1 task.stack: 0000000017b160c1
RIP: 0010:          (null)
RSP: 0018:ffff8801cbe97958 EFLAGS: 00010286
RAX: ffff8801cbcabcc0 RBX: 1ffff100397d2f2c RCX: ffffffff823afbad
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8801cbe97960
RBP: ffff8801cbe97b00 R08: 0000000000000000 R09: ffff8801caa14490
R10: 0000000000000008 R11: ffffed0039542899 R12: ffff8801ca46aed8
R13: ffff8801cbcabce8 R14: ffff8801cbe97960 R15: dffffc0000000000
FS:  0000000000da8880(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001cc79a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 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: 0033:0x440c29
RSP: 002b:00007ffd621c7628 EFLAGS: 00000203 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000004a24e1 RCX: 0000000000440c29
RDX: 0000000000000003 RSI: 000000002094ffc8 RDI: 0000000000000006
RBP: 00000000000082aa R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000000000
R13: 00000000004020b0 R14: 0000000000000000 R15: 0000000000000000
Code:  Bad RIP value.
RIP:           (null) RSP: ffff8801cbe97958
CR2: 0000000000000000
---[ end trace e3e6605bb0de7754 ]---