diff mbox

nfsd: check for use of the closed special stateid

Message ID 20171107230123.62054-1-aweits@rit.edu (mailing list archive)
State New, archived
Headers show

Commit Message

Andrew W Elble Nov. 7, 2017, 11:01 p.m. UTC 
Report on and prevent the use of the closed (invalid)
special stateid by clients.

Signed-off-by: Andrew Elble <aweits@rit.edu>
---
 fs/nfsd/nfs4state.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

Comments

J. Bruce Fields Nov. 9, 2017, 2:01 p.m. UTC | #1 
On Tue, Nov 07, 2017 at 06:01:23PM -0500, Andrew Elble wrote:
> Report on and prevent the use of the closed (invalid)
> special stateid by clients.
> 
> Signed-off-by: Andrew Elble <aweits@rit.edu>
> ---
>  fs/nfsd/nfs4state.c | 32 ++++++++++++++++++++++++++++----
>  1 file changed, 28 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 755b33284979..2b637137fecd 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -73,6 +73,7 @@
>  #define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(stateid_t)))
>  #define ONE_STATEID(stateid)  (!memcmp((stateid), &one_stateid, sizeof(stateid_t)))
>  #define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
> +#define CLOSE_STATEID(stateid)  (!memcmp((stateid), &close_stateid, sizeof(stateid_t)))
>  
>  /* forward declarations */
>  static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
> @@ -4875,13 +4876,35 @@ static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols)
>  	return nfs_ok;
>  }
>  
> +static inline __be32
> +bad_special_stateid_check(struct nfs4_client *cl, stateid_t *stateid)
> +{
> +	if (CLOSE_STATEID(stateid)) {
> +		char addr_str[INET6_ADDRSTRLEN];
> +
> +		rpc_ntop((struct sockaddr *)&cl->cl_addr, addr_str,
> +			sizeof(addr_str));
> +		pr_warn_ratelimited("NFSD: client %s using "
> +				"invalid/closed stateid\n",
> +				addr_str);

How useful is this?  If we need it I'd rather it be a dprintk.  (I'm
sort of reluctant to add new ways a badly behaved client could spam the
logs (the ratelimiting helps a little but not much).)

Seems fine otherwise.

--b.

> +		return nfserr_bad_stateid;
> +	}
> +
> +	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
> +		return nfserr_bad_stateid;
> +
> +	return nfs_ok;
> +}
> +
>  static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
>  {
>  	struct nfs4_stid *s;
> -	__be32 status = nfserr_bad_stateid;
> +	__be32 status;
>  
> -	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
> +	status = bad_special_stateid_check(cl, stateid);
> +	if (status)
>  		return status;
> +	status = nfserr_bad_stateid;
>  	/* Client debugging aid. */
>  	if (!same_clid(&stateid->si_opaque.so_clid, &cl->cl_clientid)) {
>  		char addr_str[INET6_ADDRSTRLEN];
> @@ -4938,8 +4961,9 @@ static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
>  	else if (typemask & NFS4_DELEG_STID)
>  		typemask |= NFS4_REVOKED_DELEG_STID;
>  
> -	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
> -		return nfserr_bad_stateid;
> +	status = bad_special_stateid_check(cstate->clp, stateid);
> +	if (status)
> +		return status;
>  	status = lookup_clientid(&stateid->si_opaque.so_clid, cstate, nn);
>  	if (status == nfserr_stale_clientid) {
>  		if (cstate->session)
> -- 
> 1.8.3.1
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diff mbox

Patch

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 755b33284979..2b637137fecd 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -73,6 +73,7 @@ 
 #define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(stateid_t)))
 #define ONE_STATEID(stateid)  (!memcmp((stateid), &one_stateid, sizeof(stateid_t)))
 #define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
+#define CLOSE_STATEID(stateid)  (!memcmp((stateid), &close_stateid, sizeof(stateid_t)))
 
 /* forward declarations */
 static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
@@ -4875,13 +4876,35 @@  static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols)
 	return nfs_ok;
 }
 
+static inline __be32
+bad_special_stateid_check(struct nfs4_client *cl, stateid_t *stateid)
+{
+	if (CLOSE_STATEID(stateid)) {
+		char addr_str[INET6_ADDRSTRLEN];
+
+		rpc_ntop((struct sockaddr *)&cl->cl_addr, addr_str,
+			sizeof(addr_str));
+		pr_warn_ratelimited("NFSD: client %s using "
+				"invalid/closed stateid\n",
+				addr_str);
+		return nfserr_bad_stateid;
+	}
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
+		return nfserr_bad_stateid;
+
+	return nfs_ok;
+}
+
 static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
 {
 	struct nfs4_stid *s;
-	__be32 status = nfserr_bad_stateid;
+	__be32 status;
 
-	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
+	status = bad_special_stateid_check(cl, stateid);
+	if (status)
 		return status;
+	status = nfserr_bad_stateid;
 	/* Client debugging aid. */
 	if (!same_clid(&stateid->si_opaque.so_clid, &cl->cl_clientid)) {
 		char addr_str[INET6_ADDRSTRLEN];
@@ -4938,8 +4961,9 @@  static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
 	else if (typemask & NFS4_DELEG_STID)
 		typemask |= NFS4_REVOKED_DELEG_STID;
 
-	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
-		return nfserr_bad_stateid;
+	status = bad_special_stateid_check(cstate->clp, stateid);
+	if (status)
+		return status;
 	status = lookup_clientid(&stateid->si_opaque.so_clid, cstate, nn);
 	if (status == nfserr_stale_clientid) {
 		if (cstate->session)