[RFC PATCH 13/15] LSM: restrict security_cred_getsecid() to a single LSM

From: Casey Schaufler
Date: Sat Jun 21 2025 - 13:24:23 EST


The LSM hook security_cred_getsecid() provides a single secid
that is only used by the binder driver. Provide the first value
available, and abandon any other hooks.

Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
security/security.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/security/security.c b/security/security.c
index dd167a872248..409b1cb10d35 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2740,8 +2740,13 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
*/
void security_cred_getsecid(const struct cred *c, u32 *secid)
{
+ struct lsm_static_call *scall;
+
*secid = 0;
- call_void_hook(cred_getsecid, c, secid);
+ lsm_for_each_hook(scall, cred_getsecid) {
+ scall->hl->hook.cred_getsecid(c, secid);
+ break;
+ }
}
EXPORT_SYMBOL(security_cred_getsecid);

--
2.47.0