Commit ab1016d3 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd: fix NULL dereference in nfs3svc_encode_getaclres 



In error cases the dentry may be NULL.

Before 20798dfe, the encoder also checked dentry and
d_really_is_positive(dentry), but that looks like overkill to me--zero
status should be enough to guarantee a positive dentry.

This isn't the first time we've seen an error-case NULL dereference
hidden in the initialization of a local variable in an xdr encoder.  But
I went back through the other recent rewrites and didn't spot any
similar bugs.

Reported-by: default avatarJianHong Yin <jiyin@redhat.com>
Reviewed-by: default avatarChuck Lever III <chuck.lever@oracle.com>
Fixes: 20798dfe ("NFSD: Update the NFSv3 GETACL result encoder...")
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 7b08cf62

fs/nfsd/nfs3acl.c

+2 −1
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static int nfs3svc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p) 
	struct nfsd3_getaclres *resp = rqstp->rq_resp;

	struct dentry *dentry = resp->fh.fh_dentry;

	struct kvec *head = rqstp->rq_res.head;

	struct inode *inode = d_inode(dentry);

	struct inode *inode;

	unsigned int base;

	int n;

	int w;
@@ -181,6 +181,7 @@ static int nfs3svc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p) 
		return 0;

	switch (resp->status) {

	case nfs_ok:

		inode = d_inode(dentry);

		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))

			return 0;

		if (xdr_stream_encode_u32(xdr, resp->mask) < 0)