NFS: Don't attempt to decode missing directory entries
authorBenjamin Coddington <bcodding@redhat.com>
Tue, 21 Apr 2015 18:17:35 +0000 (14:17 -0400)
committerTrond Myklebust <trond.myklebust@primarydata.com>
Thu, 23 Apr 2015 19:16:15 +0000 (15:16 -0400)
commitce85cfbed6fe3dbc01bd1976b23ac3e97878cde6
treecdc5d556a35eb0b1c5566d17ffa6a4a1767b8a50
parent3708f842e107b9b79d54a75d152e666b693649e8
NFS: Don't attempt to decode missing directory entries

If a READDIR reply comes back without any page data, avoid a NULL pointer
dereference in xdr_copy_to_scratch().

BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
IP: [<ffffffff813a378d>] memcpy+0xd/0x110
...
Call Trace:
? xdr_inline_decode+0x7a/0xb0 [sunrpc]
nfs3_decode_dirent+0x73/0x320 [nfsv3]
nfs_readdir_page_filler+0xd5/0x4e0 [nfs]
? nfs3_rpc_wrapper.constprop.9+0x42/0xc0 [nfsv3]
nfs_readdir_xdr_to_array+0x1fa/0x330 [nfs]
? mem_cgroup_commit_charge+0xac/0x160
? nfs_readdir_xdr_to_array+0x330/0x330 [nfs]
nfs_readdir_filler+0x22/0x90 [nfs]
do_read_cache_page+0x7e/0x1a0
read_cache_page+0x1c/0x20
nfs_readdir+0x18e/0x660 [nfs]
? nfs3_xdr_dec_getattr3res+0x80/0x80 [nfsv3]
iterate_dir+0x97/0x130
SyS_getdents+0x94/0x120
? fillonedir+0xd0/0xd0
system_call_fastpath+0x12/0x17

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
fs/nfs/dir.c