-----邮件原件-----
发件人: bernard@xxxxxxxx <bernard@xxxxxxxx> 代表 Paul Moore
发送时间: 2021年12月6日 11:23
收件人: 赵军奎 <bernard@xxxxxxxx>
抄送: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>; Eric Paris <eparis@xxxxxxxxxxxxxx>; selinux@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
主题: Re: [PATCH] security/selinux: fix potential memleak in error branch
On Wed, Dec 1, 2021 at 10:12 PM Bernard Zhao <bernard@xxxxxxxx> wrote:
>
> This patch try to fix potential memleak in error branch.
>
> Signed-off-by: Bernard Zhao <bernard@xxxxxxxx>
> ---
> security/selinux/hooks.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index
> 62d30c0a30c2..10700720bb74 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -983,6 +983,7 @@ static int selinux_sb_clone_mnt_opts(const struct
> super_block *oldsb, static int selinux_add_opt(int token, const char
> *s, void **mnt_opts) {
> struct selinux_mnt_opts *opts = *mnt_opts;
> + bool is_alloc_opts = false;
>
> if (token == Opt_seclabel) /* eaten and completely ignored */
> return 0;
> @@ -992,9 +993,13 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
> if (!opts)
> return -ENOMEM;
> *mnt_opts = opts;
> + is_alloc_opts = true;
> }
> - if (!s)
> + if (!s) {
> + if (is_alloc_opts)
> + kfree(opts);
> return -ENOMEM;
> + }
>Thanks for catching this and submitting a patch, but would it be simpler to do the "(!s)" check before the "(!opts)" check?
Hi paul moore：
This seems to be a good idea, thanks for your comments!
I will modify this and resubmit a version of this patch!
Thanks!
BR//Bernard
> switch (token) {
> case Opt_context:
> if (opts->context || opts->defcontext) @@ -1020,6
> +1025,8 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
> return 0;
> Einval:
> pr_warn(SEL_MOUNT_FAIL_MSG);
> + if (is_alloc_opts)
> + kfree(opts);
> return -EINVAL;
> }
>
> --
> 2.33.1
--
paul moore
www.paul-moore.com
