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From:   Gaosheng Cui <cuigaosheng1@huawei.com>
To:     <john.johansen@canonical.com>, <paul@paul-moore.com>,
        <jmorris@namei.org>, <serge@hallyn.com>, <cuigaosheng1@huawei.com>
CC:     <apparmor@lists.ubuntu.com>,
        <linux-security-module@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] apparmor: fix a memleak in multi_transaction_new()
Date:   Tue, 23 Aug 2022 09:15:03 +0800
Message-ID: <20220823011503.2757088-1-cuigaosheng1@huawei.com>
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Precedence: bulk

In multi_transaction_new(), the variable t is not freed or passed out
on the failure of copy_from_user(t->data, buf, size), which could lead
to a memleak.

Fix this bug by adding a put_multi_transaction(t) in the error path.

Fixes: 1dea3b41e84c5 ("apparmor: speed up transactional queries")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
---
 security/apparmor/apparmorfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index d066ccc219e2..7160e7aa58b9 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -868,8 +868,10 @@ static struct multi_transaction *multi_transaction_new(struct file *file,
 	if (!t)
 		return ERR_PTR(-ENOMEM);
 	kref_init(&t->count);
-	if (copy_from_user(t->data, buf, size))
+	if (copy_from_user(t->data, buf, size)) {
+		put_multi_transaction(t);
 		return ERR_PTR(-EFAULT);
+	}
 
 	return t;
 }
-- 
2.25.1