apparmor: Use struct_size() helper in kzalloc()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worse scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index f5eb9ac..1c89b05 100644 (file)
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -424,8 +424,7 @@ struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp)
        AA_BUG(size < 1);
 
        /*  + 1 for null terminator entry on vec */
-       new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1),
-                       gfp);
+       new = kzalloc(struct_size(new, vec, size + 1), gfp);
        AA_DEBUG("%s (%p)\n", __func__, new);
        if (!new)
                goto fail;

diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 4da4f3d..76cc194 100644 (file)
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -259,8 +259,7 @@ struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy,
        struct aa_profile *profile;
 
        /* freed by free_profile - usually through aa_put_profile */
-       profile = kzalloc(sizeof(*profile) + sizeof(struct aa_profile *) * 2,
-                         gfp);
+       profile = kzalloc(struct_size(profile, label.vec, 2), gfp);
        if (!profile)
                return NULL;