From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B7FAA34EEF1; Wed, 3 Dec 2025 16:04:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764777878; cv=none; b=UILToESNVcgwPwmpuw0J4tb9/bj+qREqtm2KhAY0tG5dn9qGXqfvyyQ1y/J3mv0pLSY/RBzAgiuMgR3V5riW5TuE2enT4EnIJ4CcgvweBl8pyLn6oG7qHeLT7x0fVDb3Ibg0xnuNneTNO//vzDfJT+RFrVlz4piB7ExeTmvup6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764777878; c=relaxed/simple; bh=jwZQMhBE9JC2NktYd0GjecQ60mRwf9cTWbWyt1l7FEk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gHEYv9MvoS+hzqtiWHW0Zk4AxU08I11iI9nm+SrJPBVjFKioJsj8m90+cPX9cu1jdvkchu/+AQOoPiIyFH11cqcSkcffrMmPvnOJ3y5nmIL+PSaxqArKy8BL0rtJxe+qPymHtv0UeHnhp4l7/+SiTFFho94IVtOoSUPDtORQ+w4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kgLUGvnc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kgLUGvnc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41344C4CEF5; Wed, 3 Dec 2025 16:04:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764777878; bh=jwZQMhBE9JC2NktYd0GjecQ60mRwf9cTWbWyt1l7FEk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kgLUGvncHJPLVeQgwdTU/WUBEdju8P+bVJBm8Ik90icCX1udNKh6Vc54Svz7/fmwG 6nbf2yEJoU1jCT5IYirJUOx1SVYjlep+Gr+T2Sk4v6SHP1xyrbtVmCnDJr4fwzTJcR 6tPGnthGf0eir+k4zC8Wcsa7W4XlR6v+7F6VoxG0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Al Viro , Anna Schumaker , Sasha Levin Subject: [PATCH 5.15 176/392] nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing Date: Wed, 3 Dec 2025 16:25:26 +0100 Message-ID: <20251203152420.559471817@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152414.082328008@linuxfoundation.org> References: <20251203152414.082328008@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro [ Upstream commit a890a2e339b929dbd843328f9a92a1625404fe63 ] Theoretically it's an oopsable race, but I don't believe one can manage to hit it on real hardware; might become doable on a KVM, but it still won't be easy to attack. Anyway, it's easy to deal with - since xdr_encode_hyper() is just a call of put_unaligned_be64(), we can put that under ->d_lock and be done with that. Signed-off-by: Al Viro Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1c62c4314173e..5c29e2d383639 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -365,7 +365,9 @@ static void nfs4_setup_readdir(u64 cookie, __be32 *verifier, struct dentry *dent *p++ = htonl(attrs); /* bitmap */ *p++ = htonl(12); /* attribute buffer length */ *p++ = htonl(NF4DIR); + spin_lock(&dentry->d_lock); p = xdr_encode_hyper(p, NFS_FILEID(d_inode(dentry->d_parent))); + spin_unlock(&dentry->d_lock); readdir->pgbase = (char *)p - (char *)start; readdir->count -= readdir->pgbase; -- 2.51.0