Also ensure that we always check that the size of the decoded object
matches the expectation that it must be smaller than NFS4_OPAQUE_LIMIT.
This should be true for all the current users of decode_opaque_inline(),
including decode_ace(), decode_pathname(), decode_attr_fs_locations()
and decode_exchange_id().
Note that this allows us to get rid of a number of existing checks in
decode_exchange_id(),
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/nfs4xdr.c | 29 ++++++++---------------------
1 file changed, 8 insertions(+), 21 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 5f0a6fcd0030..d10cc2a62dff 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3050,20 +3050,15 @@ static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)
{
- __be32 *p;
-
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
- *len = be32_to_cpup(p);
- p = xdr_inline_decode(xdr, *len);
- if (unlikely(!p))
- goto out_overflow;
- *string = (char *)p;
+ ssize_t ret = xdr_stream_decode_opaque_inline(xdr, (void **)string,
+ NFS4_OPAQUE_LIMIT);
+ if (unlikely(ret < 0)) {
+ if (ret == -EBADMSG)
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+ *len = ret;
return 0;
-out_overflow:
- print_overflow_msg(__func__, xdr);
- return -EIO;
}
static int decode_compound_hdr(struct xdr_stream *xdr, struct compound_hdr *hdr)
@@ -5645,8 +5640,6 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->server_owner->major_id, dummy_str, dummy);
res->server_owner->major_id_sz = dummy;
@@ -5654,8 +5647,6 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->server_scope->server_scope, dummy_str, dummy);
res->server_scope->server_scope_sz = dummy;
@@ -5670,16 +5661,12 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->impl_id->domain, dummy_str, dummy);
/* nii_name */
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->impl_id->name, dummy_str, dummy);
/* nii_date */
--
2.9.3
--
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