BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: scatterwalk_start include/crypto/scatterwalk.h:85 [inline]
IP: scatterwalk_pagedone include/crypto/scatterwalk.h:111 [inline]
IP: scatterwalk_done include/crypto/scatterwalk.h:119 [inline]
IP: blkcipher_walk_done+0xe7/0x360 crypto/blkcipher.c:123
PGD 1f9bad067 P4D 1f9bad067 PUD 1f6bbf067 PMD 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 24010 Comm: syz-executor0 Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:85 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:111 [inline]
RIP: 0010:scatterwalk_done include/crypto/scatterwalk.h:119 [inline]
RIP: 0010:blkcipher_walk_done+0xe7/0x360 crypto/blkcipher.c:123
RSP: 0018:ffffc90000ecf828 EFLAGS: 00010216
RAX: 0000000000000000 RBX: ffffc90000ecf8b0 RCX: ffffffff81739c3b
RDX: 000000000000031c RSI: ffffc900055a9000 RDI: ffff88020f2ef010
RBP: ffffc90000ecf850 R08: 538c66399530b2c1 R09: 0000000000000001
R10: ffffc90000ecf860 R11: ffff88017e20bfbc R12: 000000005186e3bb
R13: ffffc90000ecf9b0 R14: ffff88020f2ef010 R15: 0000000000000fcc
FS:  00007f0314d3b700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000020c2e6000 CR4: 00000000001426f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 glue_ctr_crypt_128bit+0x1ef/0x390 arch/x86/crypto/glue_helper.c:289
 ctr_crypt+0x34/0x40 arch/x86/crypto/serpent_avx2_glue.c:168
 __ablk_encrypt+0x43/0x50 crypto/ablk_helper.c:61
 ablk_encrypt+0xd9/0xf0 crypto/ablk_helper.c:81
 skcipher_crypt_ablkcipher crypto/skcipher.c:712 [inline]
 skcipher_decrypt_ablkcipher+0x6d/0x70 crypto/skcipher.c:730
 crypto_skcipher_decrypt include/crypto/skcipher.h:463 [inline]
 chacha_decrypt crypto/chacha20poly1305.c:152 [inline]
 poly_tail_continue+0x128/0x170 crypto/chacha20poly1305.c:167
 poly_tail+0x128/0x160 crypto/chacha20poly1305.c:201
 poly_cipherpad+0x126/0x160 crypto/chacha20poly1305.c:231
 poly_cipher+0xb9/0xd0 crypto/chacha20poly1305.c:262
 poly_adpad+0x126/0x160 crypto/chacha20poly1305.c:292
 poly_ad+0x7d/0x90 crypto/chacha20poly1305.c:316
 poly_setkey+0x107/0x130 crypto/chacha20poly1305.c:343
 poly_init+0x5a/0x70 crypto/chacha20poly1305.c:366
 poly_genkey+0x181/0x1c0 crypto/chacha20poly1305.c:406
 chacha_encrypt crypto/chacha20poly1305.c:446 [inline]
 chachapoly_encrypt+0x10c/0x130 crypto/chacha20poly1305.c:467
 crypto_aead_encrypt include/crypto/aead.h:330 [inline]
 _aead_recvmsg crypto/algif_aead.c:314 [inline]
 aead_recvmsg+0x758/0x8c0 crypto/algif_aead.c:335
 sock_recvmsg_nosec net/socket.c:809 [inline]
 sock_recvmsg+0x4d/0x70 net/socket.c:816
 ___sys_recvmsg+0x118/0x2b0 net/socket.c:2185
 __sys_recvmsg+0x4d/0x90 net/socket.c:2230
 SYSC_recvmsg net/socket.c:2242 [inline]
 SyS_recvmsg+0x2d/0x50 net/socket.c:2237
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f0314d3ac58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000002 RSI: 000000002022efc8 RDI: 0000000000000015
RBP: 0000000000000554 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6080
R13: 00000000ffffffff R14: 00007f0314d3b6d4 R15: 0000000000000000
Code: e8 8f fc c3 ff 4c 8b 73 20 44 8b 7b 28 41 8b 46 0c 41 03 46 08 41 39 c7 72 4f e8 75 fc c3 ff 4c 89 f7 e8 3d f5 0b 00 48 89 43 20 <8b> 40 08 89 43 28 e8 5e fc c3 ff 4c 8b 73 38 44 8b 7b 40 41 8b 
RIP: scatterwalk_start include/crypto/scatterwalk.h:85 [inline] RSP: ffffc90000ecf828
RIP: scatterwalk_pagedone include/crypto/scatterwalk.h:111 [inline] RSP: ffffc90000ecf828
RIP: scatterwalk_done include/crypto/scatterwalk.h:119 [inline] RSP: ffffc90000ecf828
RIP: blkcipher_walk_done+0xe7/0x360 crypto/blkcipher.c:123 RSP: ffffc90000ecf828
CR2: 0000000000000008
---[ end trace f292c55f59f392ad ]---