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 B925E2E5B36; Mon, 1 Dec 2025 11:29:46 +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=1764588586; cv=none; b=t4ra0u8E8PubXoAL/ltpIYOnuG3RKFmgx2UxGgK3A4WIc/LUjtsCp0vuEOXZkoAYovMfhcJobcFeTw3DJsJ64fzwB02MXD6IGFCCmLh8sLAbCiocQuP34W27qZRskt3lASsyts48nqM5Sb11+RPMCIfrA+8/bOquJvLAedUHv8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764588586; c=relaxed/simple; bh=5Qbth5hsRpYG3Dg4wNTbr8zrvhGr0lEXE2wM0C642Hs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UGMLjLpOzZ/Ufsp/5dklZgLaTxdNwtxUBnNIdfKPsW0dUnxhSXqCOf0tBunTSrpzI0dtc4B1FoRvfhr2bD2/gIdmfU/O6RE8c7QpOykIWpLglouw2LcFytDuwXE6LhXxGJ5AVf4v7pKRJ3yvMn9og6HOjqhW6glBRvNu5hcoD9s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=d6EWn1tm; 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="d6EWn1tm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 378E2C4CEF1; Mon, 1 Dec 2025 11:29:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764588586; bh=5Qbth5hsRpYG3Dg4wNTbr8zrvhGr0lEXE2wM0C642Hs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d6EWn1tmJW9H8dzerVb8qG9FbNMYKNe5O7Vpm7Ydw2S+ZajZcIPM+dwyHHT2drp5o pBh36msKYfPw94eMiNvQunpimnUBcayvHedx2fCLk+7r54RHN8ozjROPMdNUXm4CSu zSaJ0LK4IrX4KvZDvWM/B6nved0JjAQins3UWaEM= 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 5.4 100/187] nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing Date: Mon, 1 Dec 2025 12:23:28 +0100 Message-ID: <20251201112244.851606770@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251201112241.242614045@linuxfoundation.org> References: <20251201112241.242614045@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-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 7a4d7158c55f2..4e9b63c471af7 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -355,7 +355,9 @@ 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