syzbot

FS-Cache: O-cookie c=00000000bfe1c402 [p=00000000445b4196 fl=222 nc=0 na=1]
FS-Cache: O-cookie d=00000000a5eb7aa3 n=000000005d36a973
kasan: CONFIG_KASAN_INLINE enabled
FS-Cache: O-key=[10] '
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 4474 Comm: syz-executor242 Not tainted 4.18.0-rc4-next-20180712+ #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
34
RIP: 0010:virt_to_head_page include/linux/mm.h:638 [inline]
RIP: 0010:virt_to_cache mm/slab.c:399 [inline]
RIP: 0010:kfree+0xa0/0x260 mm/slab.c:3809
Code: 
32
82 cb 01 00 
39
00 48 ba 00 00 
34
00 80 ff 77 
36
00 00 48 01 
39
c2 48 89 df 
35
48 b8 00 00 00 
31
00 00 ea ff 
35
ff 48 c1 ea 
35
0c 48 c1 e2 
'
06 48 01 c2 <48> 
FS-Cache: N-cookie c=00000000525aeed3 [p=00000000445b4196 fl=2 nc=0 na=1]
8b 42 08 a8 01 
FS-Cache: N-cookie d=00000000a5eb7aa3 n=000000003a05f34d
48 8d 48 ff 48 
FS-Cache: N-key=[10] '
0f 45 d1 4c 8b 
34
6a 18 49 63 75 
32
74 
RSP: 0018:ffff8801b105f5d0 EFLAGS: 00010003
39
RAX: ffffea0000000000 RBX: f780d0382154ac00 RCX: 1ffff1003620bed8
RDX: 03ddef20e0855280 RSI: ffffffff87700e50 RDI: f780d0382154ac00
RBP: ffff8801b105f5f0 R08: ffff8801ade02380 R09: ffffed003620bdf8
34
R10: ffffed0039d876c0 R11: 0000000000000001 R12: 0000000000000282
R13: ffffffff87700e8a R14: ffff8801b105f740 R15: ffff8801ce4c0540
FS:  00007feab2d14700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
36
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f32b40b0000 CR3: 00000001c4338000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
39
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
35
 p9_client_version net/9p/client.c:1010 [inline]
 p9_client_create+0xfea/0x1770 net/9p/client.c:1070
31
35
35
'
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400
 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135
 legacy_get_tree+0x118/0x440 fs/fs_context.c:659
 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1743
 do_new_mount fs/namespace.c:2567 [inline]
 do_mount+0x6c1/0x1fb0 fs/namespace.c:2889
 ksys_mount+0x12d/0x140 fs/namespace.c:3105
 __do_sys_mount fs/namespace.c:3119 [inline]
 __se_sys_mount fs/namespace.c:3116 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x445b59
Code: e8 bc e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 0e fc ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007feab2d13da8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 0000000000445b59
RDX: 0000000020000180 RSI: 0000000020000140 RDI: 0000000000000000
RBP: 00000000006dac38 R08: 0000000020000300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0031656c69662f2e
R13: 6f6c3d6568636163 R14: 64663d736e617274 R15: 0000000000000001
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace bacf24c1f955b911 ]---
general protection fault: 0000 [#2] SMP KASAN
CPU: 1 PID: 4472 Comm: syz-executor242 Tainted: G      D           4.18.0-rc4-next-20180712+ #6
RIP: 0010:virt_to_head_page include/linux/mm.h:638 [inline]
RIP: 0010:virt_to_cache mm/slab.c:399 [inline]
RIP: 0010:kfree+0xa0/0x260 mm/slab.c:3809
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Code: 
RIP: 0010:virt_to_head_page include/linux/mm.h:638 [inline]
RIP: 0010:virt_to_cache mm/slab.c:399 [inline]
RIP: 0010:kfree+0xa0/0x260 mm/slab.c:3809
82 
Code: 
cb 
82 
01 
cb 
00 
01 
00 
00 
48 
00 
ba 
48 
00 00 
ba 
00 
00 
80 
00 
ff 
00 
77 
80 
00 
ff 
00 
77 
48 
00 00 
01 
48 
c2 
01 
48 
c2 
89 
48 
df 
89 
48 
df 
b8 
48 
00 
b8 
00 
00 
00 
00 
00 
00 
00 
00 
ea 
00 
ff 
ea 
ff 
ff 
48 
ff 
c1 
48 
ea 
c1 
0c 
ea 
48 
0c 
c1 
48 
e2 
c1 
06 
e2 
48 
06 
01 
48 
c2 
01 
<48> 
c2 
8b 
<48> 
42 
8b 
08 
42 
a8 
08 
01 
a8 
48 
01 
8d 
48 
48 
8d 
ff 
48 
48 
ff 
0f 
48 
45 
0f 
d1 
45 
4c 
d1 
8b 
4c 
6a 
8b 
18 
6a 
49 
18 
63 
49 
75 
63 
74 
75 
74 
RSP: 0018:ffff8801b105f5d0 EFLAGS: 00010003
RSP: 0018:ffff8801b3db75d0 EFLAGS: 00010003
RAX: ffffea0000000000 RBX: f780d0382154ac00 RCX: 1ffff1003620bed8
RDX: 03ddef20e0855280 RSI: ffffffff87700e50 RDI: f780d0382154ac00
RAX: ffffea0000000000 RBX: afd91d4db7636200 RCX: 1ffff100367b6ed8
RBP: ffff8801b105f5f0 R08: ffff8801ade02380 R09: ffffed003620bdf8
RDX: 02bf505536dd8d80 RSI: ffffffff87700e50 RDI: afd91d4db7636200
R10: ffffed0039d876c0 R11: 0000000000000001 R12: 0000000000000282
RBP: ffff8801b3db75f0 R08: ffff8801ad62a300 R09: ffffed00367b6df8
R13: ffffffff87700e8a R14: ffff8801b105f740 R15: ffff8801ce4c0540
R10: ffffed0039d876e0 R11: 0000000000000001 R12: 0000000000000282
FS:  00007feab2d14700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
R13: ffffffff87700e8a R14: ffff8801b3db7740 R15: ffff8801aa0a03c0
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
FS:  00007feab2d14700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CR2: 00007f32b40b0000 CR3: 00000001c4338000 CR4: 00000000001406f0
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
CR2: 00007f32b40b0000 CR3: 00000001c0acc000 CR4: 00000000001406e0
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000