Replace snprintf with strncpy at some places to avoid truncation

In gcc7 there are some building errors like:
directive output may be truncated writing up to 31 bytes into a region of size 24
snprintf(str, MPB_SIG_LEN, %s, mpb->sig);

It just need to copy one string to target. So use strncpy to replace it.

For this line code: snprintf(str, MPB_SIG_LEN, %s, mpb->sig);
Because mpb->sig has the content of version after magic, so
it's better to use strncpy to replace snprintf too.

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>

diff --git a/super-intel.c b/super-intel.c
index d5e9517964a91184244421dbe8f8c0cfd9929182..343f20d50215996890fb84032eb870d4cfbd6a16 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -1811,7 +1811,8 @@ static void examine_super_imsm(struct supertype *st, char *homehost)
        __u32 reserved = imsm_reserved_sectors(super, super->disks);
        struct dl *dl;
 
-       snprintf(str, MPB_SIG_LEN, "%s", mpb->sig);
+       strncpy(str, (char *)mpb->sig, MPB_SIG_LEN);
+       str[MPB_SIG_LEN-1] = '\0';
        printf("          Magic : %s\n", str);
        snprintf(str, strlen(MPB_VERSION_RAID0), "%s", get_imsm_version(mpb));
        printf("        Version : %s\n", get_imsm_version(mpb));
@@ -7142,14 +7143,16 @@ static int update_subarray_imsm(struct supertype *st, char *subarray,
 
                        u->type = update_rename_array;
                        u->dev_idx = vol;
-                       snprintf((char *) u->name, MAX_RAID_SERIAL_LEN, "%s", name);
+                       strncpy((char *) u->name, name, MAX_RAID_SERIAL_LEN);
+                       u->name[MAX_RAID_SERIAL_LEN-1] = '\0';
                        append_metadata_update(st, u, sizeof(*u));
                } else {
                        struct imsm_dev *dev;
                        int i;
 
                        dev = get_imsm_dev(super, vol);
-                       snprintf((char *) dev->volume, MAX_RAID_SERIAL_LEN, "%s", name);
+                       strncpy((char *) dev->volume, name, MAX_RAID_SERIAL_LEN);
+                       dev->volume[MAX_RAID_SERIAL_LEN-1] = '\0';
                        for (i = 0; i < mpb->num_raid_devs; i++) {
                                dev = get_imsm_dev(super, i);
                                handle_missing(super, dev);