[PATCH -next] selinux: Use struct_size() helper in kmalloc()

[PATCH -next] selinux: Use struct_size() helper in kmalloc()

[Xiu Jianfeng]

Make use of struct_size() helper instead of an open-coded calculation.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
---
 security/selinux/ss/sidtab.c | 2 +-
 security/selinux/xfrm.c      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index 656d50b09f76..293ec048af08 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -570,7 +570,7 @@ void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry,
 		goto out_unlock;
 	}
 
-	cache = kmalloc(sizeof(struct sidtab_str_cache) + str_len, GFP_ATOMIC);
+	cache = kmalloc(struct_size(cache, str, str_len), GFP_ATOMIC);
 	if (!cache)
 		goto out_unlock;
 
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index be83e5ce4469..90697317895f 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -89,7 +89,7 @@ static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
 	if (str_len >= PAGE_SIZE)
 		return -ENOMEM;
 
-	ctx = kmalloc(sizeof(*ctx) + str_len + 1, gfp);
+	ctx = kmalloc(struct_size(ctx, ctx_str, str_len + 1), gfp);
 	if (!ctx)
 		return -ENOMEM;
 
@@ -360,7 +360,7 @@ int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x,
 	if (rc)
 		return rc;
 
-	ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC);
+	ctx = kmalloc(struct_size(ctx, ctx_str, str_len), GFP_ATOMIC);
 	if (!ctx) {
 		rc = -ENOMEM;
 		goto out;
-- 
2.17.1

Re: [PATCH -next] selinux: Use struct_size() helper in kmalloc()

[Paul Moore]

On Thu, Dec 2, 2021 at 2:34 AM Xiu Jianfeng <xiujianfeng@huawei.com> wrote:
>
> Make use of struct_size() helper instead of an open-coded calculation.
>
> Link: https://github.com/KSPP/linux/issues/160
> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
> ---
>  security/selinux/ss/sidtab.c | 2 +-
>  security/selinux/xfrm.c      | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)

Merged into selinux/next, thank you.

-- 
paul moore
www.paul-moore.com