diff mbox series

fs: nfs: Added pointer check

Message ID 20221116121556.91060-1-arefev@swemel.ru
State New
Headers
Series fs: nfs: Added pointer check |

Commit Message

Denis Arefev Nov. 16, 2022, 12:15 p.m. UTC 
  Return value of a function 'xdr_inline_decode' is dereferenced at
nfs4xdr.c:5540 without checking for null,
ut it is usually checked for this function

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Arefev <arefev@swemel.ru>
---
 fs/nfs/nfs4xdr.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Trond Myklebust Nov. 16, 2022, 3:10 p.m. UTC | #1 
> On Nov 16, 2022, at 07:15, Denis Arefev <arefev@swemel.ru> wrote:
> 
> [You don't often get email from arefev@swemel.ru. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> Return value of a function 'xdr_inline_decode' is dereferenced at
> nfs4xdr.c:5540 without checking for null,
> ut it is usually checked for this function
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Denis Arefev <arefev@swemel.ru>
> ---
> fs/nfs/nfs4xdr.c | 2 ++
> 1 file changed, 2 insertions(+)
> 
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index c6dbfcae7517..571cc63ecb61 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -5533,6 +5533,8 @@ static int decode_op_map(struct xdr_stream *xdr, struct nfs4_op_map *op_map)
>        if (bitmap_words > NFS4_OP_MAP_NUM_WORDS)
>                return -EIO;
>        p = xdr_inline_decode(xdr, 4 * bitmap_words);
> +       if (!p)
> +               return -EIO;
>        for (i = 0; i < bitmap_words; i++)
>                op_map->u.words[i] = be32_to_cpup(p++);
> 

This bug was fixed in Linux 5.16 and newer by commit f114759c322e ("NFSv4: Fix potential Oops in decode_op_map()”).

_________________________________
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com
diff mbox series

Patch

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index c6dbfcae7517..571cc63ecb61 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5533,6 +5533,8 @@  static int decode_op_map(struct xdr_stream *xdr, struct nfs4_op_map *op_map)
 	if (bitmap_words > NFS4_OP_MAP_NUM_WORDS)
 		return -EIO;
 	p = xdr_inline_decode(xdr, 4 * bitmap_words);
+	if (!p)
+		return -EIO;
 	for (i = 0; i < bitmap_words; i++)
 		op_map->u.words[i] = be32_to_cpup(p++);