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Date:   Mon, 15 Jun 2020 11:12:32 -0700
Message-Id: <20200615181232.119491-1-samitolvanen@google.com>
Mime-Version: 1.0
Subject: [PATCH] security: fix the key_permission LSM hook function type
From:   Sami Tolvanen <samitolvanen@google.com>
To:     David Howells <dhowells@redhat.com>,
        James Morris <jamorris@linux.microsoft.com>,
        Kees Cook <keescook@chromium.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        KP Singh <kpsingh@google.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Thomas Cedeno <thomascedeno@google.com>,
        Anders Roxell <anders.roxell@linaro.org>
Cc:     linux-kernel@vger.kernel.org,
        Sami Tolvanen <samitolvanen@google.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Commit 8c0637e950d6 ("keys: Make the KEY_NEED_* perms an enum rather than
a mask") changed the type of the key_permission callback functions, but
didn't change the type of the hook, which trips indirect call checking with
Control-Flow Integrity (CFI). This change fixes the issue by changing the
hook type to match the functions.

Fixes: 8c0637e950d6 ("keys: Make the KEY_NEED_* perms an enum rather than a mask")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 include/linux/lsm_hook_defs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 6791813cd439..24f6683f1cfc 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -360,7 +360,7 @@ LSM_HOOK(int, 0, key_alloc, struct key *key, const struct cred *cred,
 	 unsigned long flags)
 LSM_HOOK(void, LSM_RET_VOID, key_free, struct key *key)
 LSM_HOOK(int, 0, key_permission, key_ref_t key_ref, const struct cred *cred,
-	 unsigned perm)
+	 enum key_need_perm need_perm)
 LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **_buffer)
 #endif /* CONFIG_KEYS */
 

base-commit: b3a9e3b9622ae10064826dccb4f7a52bd88c7407
-- 
2.27.0.290.gba653c62da-goog