general protection fault in mount_fs

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cb83ddcd Linux 4.14.226
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1242dd06d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=124f4e6b89b71fac
dashboard link: https://syzkaller.appspot.com/bug?extid=74a44aa0d0330274a77a

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+74a44a...@syzkaller.appspotmail.com

__fscache_acquire_cookie+0xd6/0x420 fs/fscache/cookie.c:89
fscache_acquire_cookie include/linux/fscache.h:339 [inline]
nfs_fscache_get_client_cookie+0x7f/0xe0 fs/nfs/fscache.c:40
kasan: CONFIG_KASAN_INLINE enabled
nfs_alloc_client+0x431/0x5e0 fs/nfs/client.c:188
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
nfs_get_client+0x682/0x1120 fs/nfs/client.c:435
Modules linked in:
nfs_init_server+0x21d/0xd20 fs/nfs/client.c:675
CPU: 1 PID: 5937 Comm: syz-executor.3 Not tainted 4.14.226-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880ab434280 task.stack: ffff8880a62f0000
nfs_create_server+0x7a/0x490 fs/nfs/client.c:958
RIP: 0010:__lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369
nfs_try_mount+0x122/0x750 fs/nfs/super.c:1879
RSP: 0018:ffff8880a62f73b0 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8880ab434280 R12: 0000000000000110
R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8beb5d40
nfs_fs_mount+0x1530/0x2b10 fs/nfs/super.c:2692
FS: 00007f60b37fb700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60b37fb718 CR3: 00000000a3400000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mount_fs+0x92/0x2a0 fs/super.c:1237
vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0xe53/0x2a00 fs/namespace.c:2879
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3072
flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2624
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007f32501b8188 EFLAGS: 00000246
nbd_disconnect_and_put+0xc3/0x140 drivers/block/nbd.c:1910
ORIG_RAX: 00000000000000a5
nbd_genl_disconnect+0x1fa/0x320 drivers/block/nbd.c:1948
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
genl_family_rcv_msg+0x572/0xb20 net/netlink/genetlink.c:600
RDX: 000000002015bffc RSI: 00000000200000c0 RDI: 0000000000000000
RBP: 00007f32501b81d0 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffda4ab239f R14: 00007f32501b8300 R15: 0000000000022000
genl_rcv_msg+0xaf/0x140 net/netlink/genetlink.c:625
netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
overlayfs: unrecognized mount option "� rdi" or missing value
genl_rcv+0x24/0x40 net/netlink/genetlink.c:636
netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007f60b37fb188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459
RDX: 0000000004000800 RSI: 0000000020000140 RDI: 0000000000000006
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007fff05fc6d6f R14: 00007f60b37fb300 R15: 0000000000022000
Code: 18 00 00 00 00 48 81 c4 80 01 00 00 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 2a 00 00 49 81 3c 24 a0 17 2e 8b 0f 84 5f
RIP: __lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369 RSP: ffff8880a62f73b0
---[ end trace 0beac8bc150747bd ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.