Re: avoid leak upon failed realloc

Dave Kleikamp
2007-06-18T14:04:18Z

On Sat, 2007-06-16 at 19:31 +0200, Jim Meyering wrote:
> Here's a tiny fix to avoid a leak when realloc fails:
>
> 2007-06-16 Jim Meyering <jim@meyering.net>
>
> * tdb.c (tdb_append): Don't leak a buffer when realloc fails.
>
> diff -r 777972a573b3 lib/ext2fs/tdb.c
> --- a/lib/ext2fs/tdb.c Fri Jun 15 18:05:09 2007 +0200
> +++ b/lib/ext2fs/tdb.c Sat Jun 16 19:28:50 2007 +0200
> @@ -3460,8 +3460,15 @@ int tdb_append(struct tdb_context *tdb,
> if (dbuf.dptr == NULL) {
> dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
> } else {
> - dbuf.dptr = (unsigned char *)realloc(dbuf.dptr,
> - dbuf.dsize + new_dbuf.dsize);
> + unsigned char *new_dptr
> + = (unsigned char *)realloc(dbuf.dptr,
> + dbuf.dsize + new_dbuf.dsize);
> + if (new_dptr == NULL) {
> + free(dbuf.dptr);
> + dbuf.dptr = NULL;
> + } else {
> + dbuf.dptr = new_dptr;
> + }

Not a big deal, but this part could be simplified to:

if (new_dptr == NULL)
free(dbuf.dptr);
dbuf.dptr = new_dptr;

> }
>
> if (dbuf.dptr == NULL) {
>
> Signed-off-by: Jim Meyering <jim@meyering.net>
--
David Kleikamp
IBM Linux Technology Center