[PATCH 1/1] NFSv4: check return value of xdr_inline_decode

[Pan Bian]

Function xdr_inline_decode() will return a NULL pointer if the input
buffer does not have long enough buffer to decode nbytes of data.
However, in function decode_op_map(), the return value of
xdr_inline_decode() is not validated before it is used. This patch adds
a check to the return value of xdr_inline_decode().

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
---
 fs/nfs/nfs4xdr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 80ce289..81afbbd 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5579,6 +5579,8 @@ static int decode_op_map(struct xdr_stream *xdr, struct nfs4_op_map *op_map)
 	unsigned int i;
 
 	p = xdr_inline_decode(xdr, 4);
+	if (!p)
+		return -EIO;
 	bitmap_words = be32_to_cpup(p++);
 	if (bitmap_words > NFS4_OP_MAP_NUM_WORDS)
 		return -EIO;
-- 
1.9.1