[nfs-utils PATCH] Replace non-thread-safe strtok function calls in gssd

[nfs-utils PATCH] Replace non-thread-safe strtok function calls in gssd

[Frank Sorenson]

commit fae681fa84f328cf601f34452b5a97f5d54ca2e2
Author: Frank Sorenson <sorenson@redhat.com>
Date:   2017-02-04 14:05:48 -0600

    gssd: replace non-thread-safe strtok
    
    gssd uses the non-thread-safe strtok() function, which
    can lead to incorrect program behavior.  In addition,
    strtok() modifies the input string, so error messages
    may be incomplete.
    
    Replace strtok() with the thread-safe strtok_r() and a
    per-thread state variable.  Also duplicate the input
    string for use when outputting error messages.
    
    Signed-off-by: Frank Sorenson <sorenson@redhat.com>

diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index d74d372..ba6ec29 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -729,10 +729,18 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 	char			*target = NULL;
 	char			*service = NULL;
 	char			*enctypes = NULL;
+	char			*saveptr;
+	char			*upcall_str;
 
 	printerr(2, "\n%s: '%s' (%s)\n", __func__, info->lbuf, clp->relpath);
 
-	for (p = strtok(info->lbuf, " "); p; p = strtok(NULL, " ")) {
+	upcall_str = strdup(info->lbuf);
+	if (upcall_str == NULL) {
+		printerr(0, "ERROR: malloc failure\n");
+		goto out_nomem;
+        }
+
+	for (p = strtok_r(info->lbuf, " ", &saveptr); p; p = strtok_r(NULL, " ", &saveptr)) {
 		if (!strncmp(p, "mech=", strlen("mech=")))
 			mech = p + strlen("mech=");
 		else if (!strncmp(p, "uid=", strlen("uid=")))
@@ -748,7 +756,7 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 	if (!mech || strlen(mech) < 1) {
 		printerr(0, "WARNING: handle_gssd_upcall: "
 			    "failed to find gss mechanism name "
-			    "in upcall string '%s'\n", info->lbuf);
+			    "in upcall string '%s'\n", upcall_str);
 		goto out;
 	}
 
@@ -761,7 +769,7 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 	if (!uidstr) {
 		printerr(0, "WARNING: handle_gssd_upcall: "
 			    "failed to find uid "
-			    "in upcall string '%s'\n", info->lbuf);
+			    "in upcall string '%s'\n", upcall_str);
 		goto out;
 	}
 
@@ -774,7 +782,7 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 	if (target && strlen(target) < 1) {
 		printerr(0, "WARNING: handle_gssd_upcall: "
 			 "failed to parse target name "
-			 "in upcall string '%s'\n", info->lbuf);
+			 "in upcall string '%s'\n", upcall_str);
 		goto out;
 	}
 
@@ -789,7 +797,7 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 	if (service && strlen(service) < 1) {
 		printerr(0, "WARNING: handle_gssd_upcall: "
 			 "failed to parse service type "
-			 "in upcall string '%s'\n", info->lbuf);
+			 "in upcall string '%s'\n", upcall_str);
 		goto out;
 	}
 
@@ -802,6 +810,8 @@ handle_gssd_upcall(struct clnt_upcall_info *info)
 		do_error_downcall(clp->gssd_fd, uid, -EACCES);
 	}
 out:
+	free(upcall_str);
+out_nomem:
 	free(info);
 	return;
 }

Re: [nfs-utils PATCH] Replace non-thread-safe strtok function calls in gssd

[Christoph Hellwig]

strtok_k is just as horrible as strtok, if you want to use a proper
API switch to strsep()