syzbot

binder: 17481:17486 BC_FREE_BUFFER u0000000020000000 no match
binder_alloc: 17481: binder_alloc_buf, no vma
binder: 17481:17486 transaction failed 29189/-3, size 24-24 line 2890
binder: undelivered TRANSACTION_ERROR: 29189
binder: undelivered TRANSACTION_ERROR: 29201
BUG: unable to handle kernel NULL pointer dereference at 0000000000000074
IP: virt_to_cache mm/slab.c:400 [inline]
IP: kfree+0xb2/0x250 mm/slab.c:3802
PGD 1c55eb067 P4D 1c55eb067 PUD 1cc42e067 PMD 0 
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 17508 Comm: syz-executor6 Not tainted 4.15.0-rc2+ #212
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:virt_to_cache mm/slab.c:400 [inline]
RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3802
RSP: 0018:ffff8801d9a2f780 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8801d9a2f948 RCX: ffffffffffffffff
RDX: ffffea0007668bc0 RSI: 0000000000000000 RDI: ffff8801d9a2f948
RBP: ffff8801d9a2f7a0 R08: ffff8801d48eae40 R09: ffff8801d65c8580
R10: ffff8801d9a2f950 R11: 0000000000000108 R12: 0000000000000282
R13: 0000000000000000 R14: ffff8801d9a2f948 R15: ffff8801d9a2f8b0
FS:  00007ff070118700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000074 CR3: 00000001c2759000 CR4: 00000000001426f0
Call Trace:
 blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139
 encrypt+0x20e/0x540 arch/x86/crypto/salsa20_glue.c:79
 skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline]
 skcipher_encrypt_blkcipher+0x213/0x310 crypto/skcipher.c:631
 crypto_skcipher_encrypt include/crypto/skcipher.h:445 [inline]
 _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline]
 skcipher_recvmsg+0x9e8/0xf20 crypto/algif_skcipher.c:165
 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: 0033:0x452a39
RSP: 002b:00007ff070117c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 0000000000758248 RCX: 0000000000452a39
RDX: 0000000000000101 RSI: 00000000207e0000 RDI: 0000000000000017
RBP: 000000000000060a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6190
R13: 00000000ffffffff R14: 00007ff0701186d4 R15: 0000000000000002
Code: c2 48 b8 00 00 00 00 00 ea ff ff 48 89 df 48 c1 ea 0c 48 c1 e2 06 48 01 c2 48 8b 42 20 48 8d 48 ff a8 01 48 0f 45 d1 4c 8b 6a 30 <49> 63 75 74 e8 c5 75 af ff 48 89 de 4c 89 ef 4c 8b 75 08 e8 06 
RIP: virt_to_cache mm/slab.c:400 [inline] RSP: ffff8801d9a2f780
RIP: kfree+0xb2/0x250 mm/slab.c:3802 RSP: ffff8801d9a2f780
CR2: 0000000000000074
---[ end trace c4fbb01d0506bbf8 ]---