2021-09-29 23:38:54

by Gustavo A. R. Silva

Subject: [PATCH][next] 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 <[email protected]>
---
security/apparmor/label.c | 3 +--
security/apparmor/policy.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index 6222fdfebe4e..0b0265da1926 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -425,8 +425,7 @@ 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 17191a9eae41..5827dbdfbfca 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -260,8 +260,7 @@ 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;

--
2.27.0

2021-10-01 23:39:36

by John Johansen

Subject: Re: [PATCH][next] apparmor: Use struct_size() helper in kzalloc()

On 9/29/21 3:05 PM, Gustavo A. R. Silva wrote:
> 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 <[email protected]>

nice

I will pull this into my tree
Acked-by: John Johansen <[email protected]>

> ---
> security/apparmor/label.c | 3 +--
> security/apparmor/policy.c | 3 +--
> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/security/apparmor/label.c b/security/apparmor/label.c
> index 6222fdfebe4e..0b0265da1926 100644
> --- a/security/apparmor/label.c
> +++ b/security/apparmor/label.c
> @@ -425,8 +425,7 @@ 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 17191a9eae41..5827dbdfbfca 100644
> --- a/security/apparmor/policy.c
> +++ b/security/apparmor/policy.c
> @@ -260,8 +260,7 @@ 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;
>
>

2021-10-01 23:48:41

by Gustavo A. R. Silva

Subject: Re: [PATCH][next] apparmor: Use struct_size() helper in kzalloc()

On Fri, Oct 01, 2021 at 04:37:08PM -0700, John Johansen wrote:
> On 9/29/21 3:05 PM, Gustavo A. R. Silva wrote:
> > 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 <[email protected]>
>
> nice
>
> I will pull this into my tree
> Acked-by: John Johansen <[email protected]>

Thanks, John.

--
Gustavo