Subject: general protection fault in __rds_rdma_map

From: syzbot <bot+525955f2a192792af047[email-masked]>
Date: Mon, 27 Nov 2017 10:30:01 -0800

Hello,

syzkaller hit the following crash on  
e1d1ea549b57790a3d8cf6300e6ef86118d692a3
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
RDS: rds_bind could not find a transport for 224.0.0.2, load rds_tcp or  
rds_rdma?
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3078 Comm: syzkaller719569 Not tainted 4.14.0+ #189
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
task: ffff8801cbbda580 task.stack: ffff8801cb8d0000
RIP: 0010:__rds_rdma_map+0x133/0x1050 net/rds/rdma.c:191
RSP: 0018:ffff8801cb8d7a28 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8801cb8d7bd0 RCX: ffffffff84c0b20d
RDX: 0000000000000018 RSI: ffff8801cb8d7bd0 RDI: 00000000000000c0
RBP: ffff8801cb8d7b90 R08: ffffed003971af96 R09: ffffed003971af96
R10: 0000000000000000 R11: ffffed003971af95 R12: 0000000000000000
R13: ffff8801cb407480 R14: 0000000000000000 R15: ffff8801cb407480
FS:  00007fb0be5a3700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb0be5a2e78 CR3: 00000001cfc07000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  rds_get_mr_for_dest+0x1bb/0x290 net/rds/rdma.c:357
  rds_setsockopt+0x6b9/0x970 net/rds/af_rds.c:347
  SYSC_setsockopt net/socket.c:1851 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1830
  entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x44a789
RSP: 002b:00007fb0be5a2dc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000044a789
RDX: 0000000000000007 RSI: 0000400000000114 RDI: 0000000000000004
RBP: 0000000000000086 R08: 00000000000000a0 R09: 00007fb0be5a3700
R10: 0000000020000ffc R11: 0000000000000202 R12: 0000000000000000
R13: 00000000007efe3f R14: 00007fb0be5a39c0 R15: 0000000000000000
Code: 57 0d 00 00 48 8b 85 f0 fe ff ff 4c 8b a0 c0 04 00 00 48 b8 00 00 00  
00 00 fc ff df 49 8d bc 24 c0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00  
0f 85 6a 0e 00 00 49 83 bc 24 c0 00 00 00 00 0f 84
RIP: __rds_rdma_map+0x133/0x1050 net/rds/rdma.c:191 RSP: ffff8801cb8d7a28
---[ end trace 5e0e31770c7b70a7 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
    (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
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