Add error checking for calls to sprintf - it can fail for more

reasons than just 'out-of-space'.

diff --git a/daemons/cmirrord/functions.c b/daemons/cmirrord/functions.c
index 1412b8e5581794f12934da91263c7f20a735a500..92d752c23e1821bf40fe9915ae4635bdca9a88ed 100644 (file)
--- a/daemons/cmirrord/functions.c
+++ b/daemons/cmirrord/functions.c
@@ -1371,15 +1371,21 @@ static int clog_get_sync_count(struct dm_ulog_request *rq, uint32_t originator)
 
 static int core_status_info(struct log_c *lc __attribute((unused)), struct dm_ulog_request *rq)
 {
+       int r;
        char *data = (char *)rq->data;
 
-       rq->data_size = sprintf(data, "1 clustered-core");
+       r = sprintf(data, "1 clustered-core");
+       if (r < 0)
+               return r;
+
+       rq->data_size = r;
 
        return 0;
 }
 
 static int disk_status_info(struct log_c *lc, struct dm_ulog_request *rq)
 {
+       int r;
        char *data = (char *)rq->data;
        struct stat statbuf;
 
@@ -1388,9 +1394,13 @@ static int disk_status_info(struct log_c *lc, struct dm_ulog_request *rq)
                return -errno;
        }
 
-       rq->data_size = sprintf(data, "3 clustered-disk %d:%d %c",
-                               major(statbuf.st_rdev), minor(statbuf.st_rdev),
-                               (lc->log_dev_failed) ? 'D' : 'A');
+       r = sprintf(data, "3 clustered-disk %d:%d %c",
+                   major(statbuf.st_rdev), minor(statbuf.st_rdev),
+                   (lc->log_dev_failed) ? 'D' : 'A');
+       if (r < 0)
+               return r;
+
+       rq->data_size = r;
 
        return 0;
 }
@@ -1421,18 +1431,24 @@ static int clog_status_info(struct dm_ulog_request *rq)
 
 static int core_status_table(struct log_c *lc, struct dm_ulog_request *rq)
 {
+       int r;
        char *data = (char *)rq->data;
 
-       rq->data_size = sprintf(data, "clustered-core %u %s%s ",
-                               lc->region_size,
-                               (lc->sync == DEFAULTSYNC) ? "" :
-                               (lc->sync == NOSYNC) ? "nosync " : "sync ",
-                               (lc->block_on_error) ? "block_on_error" : "");
+       r = sprintf(data, "clustered-core %u %s%s ",
+                   lc->region_size,
+                   (lc->sync == DEFAULTSYNC) ? "" :
+                   (lc->sync == NOSYNC) ? "nosync " : "sync ",
+                   (lc->block_on_error) ? "block_on_error" : "");
+       if (r < 0)
+               return r;
+
+       rq->data_size = r;
        return 0;
 }
 
 static int disk_status_table(struct log_c *lc, struct dm_ulog_request *rq)
 {
+       int r;
        char *data = (char *)rq->data;
        struct stat statbuf;
 
@@ -1441,12 +1457,16 @@ static int disk_status_table(struct log_c *lc, struct dm_ulog_request *rq)
                return -errno;
        }
 
-       rq->data_size = sprintf(data, "clustered-disk %d:%d %u %s%s ",
-                               major(statbuf.st_rdev), minor(statbuf.st_rdev),
-                               lc->region_size,
-                               (lc->sync == DEFAULTSYNC) ? "" :
-                               (lc->sync == NOSYNC) ? "nosync " : "sync ",
-                               (lc->block_on_error) ? "block_on_error" : "");
+       r = sprintf(data, "clustered-disk %d:%d %u %s%s ",
+                   major(statbuf.st_rdev), minor(statbuf.st_rdev),
+                   lc->region_size,
+                   (lc->sync == DEFAULTSYNC) ? "" :
+                   (lc->sync == NOSYNC) ? "nosync " : "sync ",
+                   (lc->block_on_error) ? "block_on_error" : "");
+       if (r < 0)
+               return r;
+
+       rq->data_size = r;
        return 0;
 }
 
@@ -1555,6 +1575,11 @@ out:
  * from this function.  However, an inability to successfully
  * perform the request will fill in the 'rq->error' field.
  *
+ * 'rq' (or more correctly, rq->u_rq.data) should be of sufficient
+ * size to hold any returning data.  Currently, local.c uses 2kiB
+ * to hold 'rq' - leaving ~1.5kiB for return data... more than
+ * enough for all the implemented functions here.
+ *
  * Returns: 0 on success, -EXXX on error
  */
 int do_request(struct clog_request *rq, int server)