[PATCH 2/2] NFSv4: Fix potential Oops in decode_op_map()

trondmy
2021-11-04T21:59:04Z

From: Trond Myklebust <trond.myklebust@hammerspace.com>

The return value of xdr_inline_decode() is not being checked, leading to
a potential Oops. Just replace the open coded array decode with the
generic XDR version.

Reported-by: <rtm@csail.mit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/nfs4xdr.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index fa01edf19015..69862bf6db00 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5567,20 +5567,9 @@ static int decode_secinfo_no_name(struct xdr_stream *xdr, struct nfs4_secinfo_re

static int decode_op_map(struct xdr_stream *xdr, struct nfs4_op_map *op_map)
{
- __be32 *p;
- uint32_t bitmap_words;
- 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)
+ if (xdr_stream_decode_uint32_array(xdr, op_map->u.words,
+ ARRAY_SIZE(op_map->u.words)) < 0)
return -EIO;
- p = xdr_inline_decode(xdr, 4 * bitmap_words);
- for (i = 0; i < bitmap_words; i++)
- op_map->u.words[i] = be32_to_cpup(p++);
-
return 0;
}

--
2.33.1