bpf: Switch to krealloc_array()

Let the krealloc_array() copy the original data and
check for a multiplication overflow.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240429120005.3539116-1-andriy.shevchenko@linux.intel.com

kernel/bpf/core.c

@@ -850,7 +850,7 @@ int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 		return -EINVAL;
 	}
 
-	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
+	tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
 	if (!tab)
 		return -ENOMEM;