From: Pan Bian <bianpan2016@163.com>
Date: Sun, 23 Apr 2017 06:49:41 +0000 (+0800)
Subject: NFSv4: check return value of xdr_inline_decode
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4edabfd7d0f7d39eeda8ffac76d9e884c22951d9;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

NFSv4: check return value of xdr_inline_decode

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@163.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 125212588115..dbfe48ac3529 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5570,6 +5570,8 @@ 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;