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From:   Roberto Sassu <roberto.sassu@huaweicloud.com>
To:     paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com,
        zohar@linux.ibm.com
Cc:     linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
        Roberto Sassu <roberto.sassu@huawei.com>,
        stable@vger.kernel.org
Subject: [PATCH v2] security: Restore passing final prot to ima_file_mmap()
Date:   Wed, 21 Dec 2022 15:10:07 +0100
Message-Id: <20221221141007.2579770-1-roberto.sassu@huaweicloud.com>
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From: Roberto Sassu <roberto.sassu@huawei.com>

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") moved the code to update prot with the
actual protection flags to be granted to the requestor by the kernel to a
helper called mmap_prot(). However, the patch didn't update the argument
passed to ima_file_mmap(), making it receive the requested prot instead of
the final computed prot.

A possible consequence is that files mmapped as executable might not be
measured/appraised if PROT_EXEC is not requested but subsequently added in
the final prot.

Replace prot with mmap_prot(file, prot) as the second argument of
ima_file_mmap() to restore the original behavior.

Cc: stable@vger.kernel.org
Fixes: 98de59bfe4b2 ("take calculation of final prot in security_mmap_file() into a helper")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 security/security.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/security.c b/security/security.c
index d1571900a8c7..0d2359d588a1 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1666,7 +1666,7 @@ int security_mmap_file(struct file *file, unsigned long prot,
 					mmap_prot(file, prot), flags);
 	if (ret)
 		return ret;
-	return ima_file_mmap(file, prot);
+	return ima_file_mmap(file, mmap_prot(file, prot));
 }
 
 int security_mmap_addr(unsigned long addr)
-- 
2.25.1