e2image: Fix potential overflow if the device name is too long

Adapted from SLES's patch: e2fsprogs-strncat.patch

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/misc/e2image.c b/misc/e2image.c
index f17b784..4313cc0 100644 (file)
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -126,7 +126,7 @@ static void write_image_file(ext2_filsys fs, int fd)
        hdr.magic_number = EXT2_ET_MAGIC_E2IMAGE;
        strcpy(hdr.magic_descriptor, "Ext2 Image 1.0");
        gethostname(hdr.fs_hostname, sizeof(hdr.fs_hostname));
-       strncat(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name));
+       strncpy(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name)-1);
        hdr.fs_device_name[sizeof(hdr.fs_device_name) - 1] = 0;
        hdr.fs_blocksize = fs->blocksize;