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_copychunks+0x16e/0x200 crypto/scatterwalk.c:55 PGD 20e1ae067 P4D 20e1ae067 PUD 1dcb96067 PMD 0 Oops: 0000 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 16367 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_copychunks+0x16e/0x200 crypto/scatterwalk.c:55 RSP: 0018:ffffc9000142f790 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000341 RCX: ffffffff81739c3b RDX: 0000000000000720 RSI: ffffc90002dd5000 RDI: ffff8801dc93f350 RBP: ffffc9000142f7c8 R08: 000000000002c0c8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000341 R13: ffff8801dc93f350 R14: 0000000000000005 R15: ffffc9000142f8d0 FS: 00007fe081c4a700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000001dfdba000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: blkcipher_next_slow crypto/blkcipher.c:174 [inline] blkcipher_walk_next+0x4c0/0x590 crypto/blkcipher.c:254 blkcipher_walk_done+0x1a8/0x360 crypto/blkcipher.c:132 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:00007fe081c49c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 RDX: 0000000000000002 RSI: 00000000208e1000 RDI: 0000000000000015 RBP: 0000000000000048 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee760 R13: 00000000ffffffff R14: 00007fe081c4a6d4 R15: 0000000000000000 Code: 4d 8b 2f 4c 01 65 c8 4d 29 e6 45 8b 65 0c 45 03 65 08 44 39 e3 0f 82 d4 fe ff ff e8 bd 25 c4 ff 4c 89 ef e8 85 1e 0c 00 49 89 07 <8b> 58 08 49 89 c5 41 89 5f 08 44 8b 60 0c 44 03 60 08 e9 ad fe RIP: scatterwalk_start include/crypto/scatterwalk.h:85 [inline] RSP: ffffc9000142f790 RIP: scatterwalk_pagedone include/crypto/scatterwalk.h:111 [inline] RSP: ffffc9000142f790 RIP: scatterwalk_copychunks+0x16e/0x200 crypto/scatterwalk.c:55 RSP: ffffc9000142f790 CR2: 0000000000000008 ---[ end trace fe653cd8f102ee9d ]---