Hi Casey,
On Sun, Jun 2, 2019 at 6:53 PM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> LSM hooks dealing with security context strings should
> only be called for one security module. Add call macros
> that invoke a single module hook and us in for those cases.
>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> ---
> security/security.c | 32 ++++++++++++++++++++++++++++----
> 1 file changed, 28 insertions(+), 4 deletions(-)
>
> diff --git a/security/security.c b/security/security.c
> index 69983ad68233..365970f2501d 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -698,6 +698,16 @@ int lsm_superblock_alloc(struct super_block *sb)
> P->hook.FUNC(__VA_ARGS__); \
> } while (0)
>
> +#define call_one_void_hook(FUNC, ...) \
> + do { \
> + struct security_hook_list *P; \
> + \
> + hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \
> + P->hook.FUNC(__VA_ARGS__); \
> + break; \
> + } \
> + } while (0)
> +
> #define call_int_hook(FUNC, IRC, ...) ({ \
> int RC = IRC; \
> do { \
> @@ -712,6 +722,19 @@ int lsm_superblock_alloc(struct super_block *sb)
> RC; \
> })
>
> +#define call_one_int_hook(FUNC, IRC, ...) ({ \
> + int RC = IRC; \
> + do { \
> + struct security_hook_list *P; \
> + \
> + hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \
> + RC = P->hook.FUNC(__VA_ARGS__); \
> + break; \
> + } \
> + } while (0); \
> + RC; \
> +})
> +
> /* Security operations */
>
> int security_binder_set_context_mgr(struct task_struct *mgr)
> @@ -1951,7 +1974,8 @@ EXPORT_SYMBOL(security_ismaclabel);
>
> int security_secid_to_secctx(struct lsm_export *l, char **secdata, u32 *seclen)
> {
> - return call_int_hook(secid_to_secctx, -EOPNOTSUPP, l, secdata, seclen);
> + return call_one_int_hook(secid_to_secctx, -EOPNOTSUPP, l, secdata,
> + seclen);
> }
> EXPORT_SYMBOL(security_secid_to_secctx);
>
> @@ -1959,13 +1983,13 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
> struct lsm_export *l)
> {
> lsm_export_init(l);
> - return call_int_hook(secctx_to_secid, 0, secdata, seclen, l);
> + return call_one_int_hook(secctx_to_secid, 0, secdata, seclen, l);
> }
> EXPORT_SYMBOL(security_secctx_to_secid);
>
> void security_release_secctx(char *secdata, u32 seclen)
> {
> - call_void_hook(release_secctx, secdata, seclen);
> + call_one_void_hook(release_secctx, secdata, seclen);
> }
> EXPORT_SYMBOL(security_release_secctx);
>
> @@ -2090,7 +2114,7 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
> int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> int __user *optlen, unsigned len)
> {
> - return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
> + return call_one_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
> optval, optlen, len);
> }
>
> --
> 2.19.1
>
Shouldn't dentry_init_security() use call_one_int_hook() as well? It
also returns a context string.
Thanks,
--
Ondrej Mosnacek <omosnace at redhat dot com>
Software Engineer, Security Technologies
Red Hat, Inc.
