On Wed, Jun 10, 2020 at 2:10 PM <trix@xxxxxxxxxx> wrote:
>
> From: Tom Rix <trix@xxxxxxxxxx>
>
> Clang's static analysis tool reports these double free memory errors.
>
> security/selinux/ss/services.c:2987:4: warning: Attempt to free released memory [unix.Malloc]
> kfree(bnames[i]);
> ^~~~~~~~~~~~~~~~
> security/selinux/ss/services.c:2990:2: warning: Attempt to free released memory [unix.Malloc]
> kfree(bvalues);
> ^~~~~~~~~~~~~~
>
> So improve the security_get_bools error handling by freeing these variables
> and setting their return pointers to NULL and the return len to 0
>
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> ---
> security/selinux/ss/services.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index 313919bd42f8..2dffae1feaff 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -2888,8 +2888,12 @@ int security_get_bools(struct selinux_state *state,
> if (*names) {
> for (i = 0; i < *len; i++)
> kfree((*names)[i]);
> + kfree(names);
kfree(*names)?
> }
> kfree(*values);
> + *len = 0;
> + *names = NULL;
> + *values = NULL;
> goto out;
> }
Wondering if the caller handling ought to be changed too even though
this should avoid the problem.
