general protection fault in __crypto_alg_lookup

[syzbot]

Hello,

syzkaller hit the following crash on
6084b576dca2e898f5c101baef151f7bfdbb606d
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.

Unfortunately, I don't have any reproducer for this bug yet.


SELinux: unrecognized netlink message: protocol=0 nlmsg_type=256
sclass=netlink_route_socket pig=17315 comm=syz-executor6
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=256
sclass=netlink_route_socket pig=17326 comm=syz-executor6
general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17336 Comm: syz-executor7 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:__crypto_alg_lookup+0x43/0x190 crypto/api.c:63
RSP: 0018:ffffc90000d7fcb8 EFLAGS: 00010216
RAX: 0000000000010000 RBX: 623e2d6261746826 RCX: ffffffff816741f3
RDX: 00000000000000d9 RSI: ffffc90001a01000 RDI: ffff8801f9d11891
RBP: ffffc90000d7fd00 R08: 0000000000000001 R09: 0000000000000001
R10: ffffc90000d7fc80 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000072612f66 R14: 000000000000240e R15: 000000000000040f
FS: 00007ff6c7ec5700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020f35000 CR3: 00000001fce0e004 CR4: 00000000001606e0
Call Trace:
crypto_alg_lookup+0x31/0x50 crypto/api.c:201
crypto_larval_lookup.part.8+0x34/0x1c0 crypto/api.c:218
crypto_larval_lookup crypto/api.c:212 [inline]
crypto_alg_mod_lookup+0x77/0x120 crypto/api.c:271
crypto_find_alg crypto/api.c:501 [inline]
crypto_alloc_tfm+0x67/0x180 crypto/api.c:534
crypto_alloc_ahash+0x2c/0x40 crypto/ahash.c:540
hash_bind+0x51/0x90 crypto/algif_hash.c:422
alg_bind+0x94/0x180 crypto/af_alg.c:179
SYSC_bind+0xa8/0x130 net/socket.c:1454
SyS_bind+0x24/0x30 net/socket.c:1440
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007ff6c7ec4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452a09
RDX: 0000000000000058 RSI: 0000000020f35000 RDI: 0000000000000013
RBP: 0000000000000554 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5080
R13: 00000000ffffffff R14: 00007ff6c7ec56d4 R15: 0000000000000000
Code: 89 7d d0 e8 70 61 c4 ff 48 8b 1d 89 df a6 01 48 81 fb 60 21 0e 83 0f
84 4c 01 00 00 c7 45 c4 fe ff ff ff 45 31 e4 e8 4d 61 c4 ff <44> 8b 6b 20
41 f6 c5 60 0f 85 03 01 00 00 e8 3a 61 c4 ff 44 89
RIP: __crypto_alg_lookup+0x43/0x190 crypto/api.c:63 RSP: ffffc90000d7fcb8
---[ end trace 17ac9655be6571e5 ]---
Kernel panic - not syncing: Fatal exception
netlink: 5 bytes leftover after parsing attributes in process
`syz-executor6'.
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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[Eric Biggers]

Invalidating this bug now that a similar one has been fixed; we'll see if it
happens again...

#syz invalid