[PATCH for-4.15 1/5] tools/xenstored: Avoid unnecessary talloc_strdup() in do_control_lu()

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

At the moment, the return of talloc_strdup() is not checked. This means
we may dereference a NULL pointer if the allocation failed.

However, it is pointless to allocate the memory as send_reply() will
copy the data to a different buffer. So drop the use of talloc_strdup().

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Fixes: fecab256d474 ("tools/xenstore: add basic live-update command parsing")
Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 tools/xenstore/xenstored_control.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/xenstore/xenstored_control.c 
b/tools/xenstore/xenstored_control.c
index f10beaf85eb4..e8a501acdb62 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -691,7 +691,6 @@ static const char *lu_start(const void *ctx, struct 
connection *conn,
 static int do_control_lu(void *ctx, struct connection *conn,
                         char **vec, int num)
 {
-       const char *resp;
        const char *ret = NULL;
        unsigned int i;
        bool force = false;
@@ -734,8 +733,7 @@ static int do_control_lu(void *ctx, struct connection *conn,
 
        if (!ret)
                ret = "OK";
-       resp = talloc_strdup(ctx, ret);
-       send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
+       send_reply(conn, XS_CONTROL, ret, strlen(ret) + 1);
        return 0;
 }
 #endif
-- 
2.17.1