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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, Al Viro <viro@zeniv.linux.org.uk>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.3 015/105] autofs: fix a leak in autofs_expire_indirect()
Date:   Wed, 11 Dec 2019 16:05:04 +0100
Message-Id: <20191211150224.377878970@linuxfoundation.org>
In-Reply-To: <20191211150221.153659747@linuxfoundation.org>
References: <20191211150221.153659747@linuxfoundation.org>
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From: Al Viro <viro@zeniv.linux.org.uk>

[ Upstream commit 03ad0d703df75c43f78bd72e16124b5b94a95188 ]

if the second call of should_expire() in there ends up
grabbing and returning a new reference to dentry, we need
to drop it before continuing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/autofs/expire.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c
index cdff0567aacb3..2d01553a6d586 100644
--- a/fs/autofs/expire.c
+++ b/fs/autofs/expire.c
@@ -498,9 +498,10 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb,
 		 */
 		how &= ~AUTOFS_EXP_LEAVES;
 		found = should_expire(expired, mnt, timeout, how);
-		if (!found || found != expired)
-			/* Something has changed, continue */
+		if (found != expired) { // something has changed, continue
+			dput(found);
 			goto next;
+		}
 
 		if (expired != dentry)
 			dput(dentry);
-- 
2.20.1