On Tue, Jun 14, 2022 at 3:35 PM xiujianfeng <[email protected]> wrote:
>
>
> 在 2022/6/14 20:57, Ondrej Mosnacek 写道:
> > On Mon, Jun 13, 2022 at 4:02 PM Xiu Jianfeng <[email protected]> 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 <[email protected]>
> >> ---
> >> 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?
> No problem, patch already sent.
Wow, you're fast :) Thanks!
--
Ondrej Mosnacek
Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.