misc: fix strncpy length complaints

[thirdparty/xfsprogs-dev.git] / mkfs / xfs_mkfs.c

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 3e2ef92d8de0ef7b434a60e4fb0f26d3309449e9..db3ad38ea1e0bb8831e8bcf961fe6b76ea633f9f 100644 (file)
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -3270,8 +3270,17 @@ finish_superblock_setup(
        struct xfs_mount        *mp,
        struct xfs_sb           *sbp)
 {
-       if (cfg->label)
-               strncpy(sbp->sb_fname, cfg->label, sizeof(sbp->sb_fname));
+       if (cfg->label) {
+               size_t          label_len;
+
+               /*
+                * Labels are null terminated unless the string fits exactly
+                * in the label field, so assume sb_fname is zeroed and then
+                * do a memcpy because the destination isn't a normal C string.
+                */
+               label_len = min(sizeof(sbp->sb_fname), strlen(cfg->label));
+               memcpy(sbp->sb_fname, cfg->label, label_len);
+       }
 
        sbp->sb_dblocks = cfg->dblocks;
        sbp->sb_rblocks = cfg->rtblocks;