From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Mimi Zohar <zohar@linux.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH][next] ima: ima_modsig: Fix use-after-free bug in ima_read_modsig
Date: Sun, 11 Aug 2019 18:55:07 -0500 [thread overview]
Message-ID: <20190811235507.GA9587@embeddedor> (raw)
hdr is being freed and then dereferenced by accessing hdr->pkcs7_msg
Fix this by copying the value returned by PTR_ERR(hdr->pkcs7_msg) into
automatic variable err for its safe use after freeing hdr.
Addresses-Coverity-ID: 1485813 ("Read from pointer after free")
Fixes: 39b07096364a ("ima: Implement support for module-style appended signatures")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
security/integrity/ima/ima_modsig.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
index c412e31d1714..e681d4326145 100644
--- a/security/integrity/ima/ima_modsig.c
+++ b/security/integrity/ima/ima_modsig.c
@@ -91,8 +91,9 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len);
if (IS_ERR(hdr->pkcs7_msg)) {
+ int err = PTR_ERR(hdr->pkcs7_msg);
kfree(hdr);
- return PTR_ERR(hdr->pkcs7_msg);
+ return err;
}
memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
--
2.22.0
next reply other threads:[~2019-08-12 0:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-11 23:55 Gustavo A. R. Silva [this message]
2019-08-28 13:50 ` [PATCH][next] ima: ima_modsig: Fix use-after-free bug in ima_read_modsig Mimi Zohar
2019-08-28 18:55 ` Gustavo A. R. Silva
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