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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sascha Hauer <s.hauer@pengutronix.de>,
        Mimi Zohar <zohar@linux.ibm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.3 090/148] ima: fix freeing ongoing ahash_request
Date:   Thu, 10 Oct 2019 10:35:51 +0200
Message-Id: <20191010083616.787812636@linuxfoundation.org>
In-Reply-To: <20191010083609.660878383@linuxfoundation.org>
References: <20191010083609.660878383@linuxfoundation.org>
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From: Sascha Hauer <s.hauer@pengutronix.de>

[ Upstream commit 4ece3125f21b1d42b84896c5646dbf0e878464e1 ]

integrity_kernel_read() can fail in which case we forward to call
ahash_request_free() on a currently running request. We have to wait
for its completion before we can free the request.

This was observed by interrupting a "find / -type f -xdev -print0 | xargs -0
cat 1>/dev/null" with ctrl-c on an IMA enabled filesystem.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/integrity/ima/ima_crypto.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 7532b062be594..73044fc6a9521 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -271,6 +271,11 @@ static int ima_calc_file_hash_atfm(struct file *file,
 		if (rc != rbuf_len) {
 			if (rc >= 0)
 				rc = -EINVAL;
+			/*
+			 * Forward current rc, do not overwrite with return value
+			 * from ahash_wait()
+			 */
+			ahash_wait(ahash_rc, &wait);
 			goto out3;
 		}
 
-- 
2.20.1