From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
[ Upstream commit 6e4891dc289cd191d46ab7ba1dcb29646644f9ca ]
In the case we already have a struct file (derived from a stateid), we
still need to do permission-checking; otherwise an unauthorized user
could gain access to a file by sniffing or guessing somebody else's
stateid.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: dc97618ddda9 "nfsd4: separate splice and readv cases"
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 2a77603..6abe965 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3229,6 +3229,7 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
unsigned long maxcount;
struct xdr_stream *xdr = &resp->xdr;
struct file *file = read->rd_filp;
+ struct svc_fh *fhp = read->rd_fhp;
int starting_len = xdr->buf->len;
struct raparms *ra;
__be32 *p;
@@ -3252,12 +3253,15 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
maxcount = min_t(unsigned long, maxcount, (xdr->buf->buflen - xdr->buf->len));
maxcount = min_t(unsigned long, maxcount, read->rd_length);
- if (!read->rd_filp) {
+ if (read->rd_filp)
+ err = nfsd_permission(resp->rqstp, fhp->fh_export,
+ fhp->fh_dentry,
+ NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
+ else
err = nfsd_get_tmp_read_open(resp->rqstp, read->rd_fhp,
&file, &ra);
- if (err)
- goto err_truncate;
- }
+ if (err)
+ goto err_truncate;
if (file->f_op->splice_read && resp->rqstp->rq_splice_ok)
err = nfsd4_encode_splice_read(resp, read, file, maxcount);
--
2.1.0
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