On Mon, Jun 13, 2022 at 4:02 PM Xiu Jianfeng <xiujianfeng@xxxxxxxxxx> wrote:
> In this function, it directly returns the result of __security_read_policy
> without freeing the allocated memory in *data, cause memory leak issue,
> so free the memory if __security_read_policy failed.
>
> Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
> ---
> security/selinux/ss/services.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index 69b2734311a6..fe5fcf571c56 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -4048,6 +4048,7 @@ int security_read_policy(struct selinux_state *state,
> int security_read_state_kernel(struct selinux_state *state,
> void **data, size_t *len)
> {
> + int err;
> struct selinux_policy *policy;
>
> policy = rcu_dereference_protected(
> @@ -4060,5 +4061,11 @@ int security_read_state_kernel(struct selinux_state *state,
> if (!*data)
> return -ENOMEM;
>
> - return __security_read_policy(policy, *data, len);
> + err = __security_read_policy(policy, *data, len);
> + if (err) {
> + vfree(*data);
> + *data = NULL;
> + *len = 0;
> + }
> + return err;
> }
> --
> 2.17.1
>
security_read_policy() defined a few lines above has the same pattern
(just with vmalloc_user() in place of vmalloc()). Would you like to
send another patch to fix that function as well?
--
Ondrej Mosnacek
Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.
