From 2bcda8386aef48863555ea8aecc3967dc2818182 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 6 Jun 2019 13:18:53 -0500 Subject: [PATCH] kernel: module: Use struct_size() helper commit 8d1b73dd25ff92c3fa9807a20c22fa2b44c07336 upstream. One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct module_sect_attrs { ... struct module_sect_attr attrs[0]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0] with: struct_size(sect_attrs, attrs, nloaded) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman --- kernel/module.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 08d4b7811ae5..b9436e86b51c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1491,8 +1491,7 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info) for (i = 0; i < info->hdr->e_shnum; i++) if (!sect_empty(&info->sechdrs[i])) nloaded++; - size[0] = ALIGN(sizeof(*sect_attrs) - + nloaded * sizeof(sect_attrs->attrs[0]), + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), sizeof(sect_attrs->grp.attrs[0])); size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);