NFS: decode_dirent should use an xdr_stream
Convert nfs*xdr.c to use an xdr stream in decode_dirent. This will prevent a
kernel oops that has been occuring when reading a vmapped page.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 79c7438..0210c75 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -500,25 +500,56 @@
goto out;
}
-__be32 *
-nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
+static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
- if (!*p++) {
- if (!*p)
+ dprintk("nfs: %s: prematurely hit end of receive buffer. "
+ "Remaining buffer length is %tu words.\n",
+ func, xdr->end - xdr->p);
+}
+
+__be32 *
+nfs_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
+{
+ __be32 *p;
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(!p))
+ goto out_overflow;
+
entry->ino = ntohl(*p++);
entry->len = ntohl(*p++);
+
+ p = xdr_inline_decode(xdr, entry->len + 4);
+ if (unlikely(!p))
+ goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
entry->prev_cookie = entry->cookie;
entry->cookie = ntohl(*p++);
- entry->eof = !p[0] && p[1];
+
+ p = xdr_inline_peek(xdr, 8);
+ if (p != NULL)
+ entry->eof = !p[0] && p[1];
+ else
+ entry->eof = 0;
return p;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return ERR_PTR(-EIO);
}
/*