On Wed, Oct 13, 2021 at 2:54 PM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> Do not sort empty records to avoid calling qsort(3) with a NULL pointer.
> qsort(3) might be annotated with the function attribute nonnull and
> UBSan then complains:
>
> database_join.c:80:2: runtime error: null pointer passed as argument 1, which is declared to never be null
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> libsemanage/src/database_join.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/libsemanage/src/database_join.c b/libsemanage/src/database_join.c
> index b9b35a61..b0e66e53 100644
> --- a/libsemanage/src/database_join.c
> +++ b/libsemanage/src/database_join.c
> @@ -77,10 +77,12 @@ static int dbase_join_cache(semanage_handle_t * handle, dbase_join_t * dbase)
> goto err;
>
> /* Sort for quicker merge later */
> - qsort(records1, rcount1, sizeof(record1_t *),
> - (int (*)(const void *, const void *))rtable1->compare2_qsort);
> - qsort(records2, rcount2, sizeof(record2_t *),
> - (int (*)(const void *, const void *))rtable2->compare2_qsort);
> + if (rcount1 > 0)
> + qsort(records1, rcount1, sizeof(record1_t *),
> + (int (*)(const void *, const void *))rtable1->compare2_qsort);
> + if (rcount2 > 0)
> + qsort(records2, rcount2, sizeof(record2_t *),
> + (int (*)(const void *, const void *))rtable2->compare2_qsort);
>
> /* Now merge into this dbase */
> while (i < rcount1 || j < rcount2) {
> --
> 2.33.0
>
Hello,
This patch looks good, and the code would be more readable with braces
around the qsort calls (so it is clear with a fast glance over the
code that there is no issue of not using braces here). Could you add
braces like this?
if (rcount1 > 0) {
qsort(records1, rcount1, sizeof(record1_t *),
(int (*)(const void *, const void *))rtable1->compare2_qsort);
}
Thanks,
Nicolas
