From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 F37C640D585; Thu, 11 Jun 2026 17:31:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781199066; cv=none; b=AAF156L7zGzcDIk4ocZdGUyAWM4JWusPxNxtY1+4T5O9ad/X/4R6KJVF01LqETEm/wfeQEhx79NzG4vigkPyY7x0QoA7Dsp1QjRvjElDArp6nkCqNsIrmlJ+YQOf+DBdhwILggVR/EPGY15J9NCoWFvQnbjDXCFd5qveAAKmxeg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781199066; c=relaxed/simple; bh=3v65/q5WcsjJD3zNFcCxjQ3wajQxxQ01TpLu0g7i4Ak=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=CY/61CVlI/1kP6ZAKDsSBt0d6dEWI/ih4NfQrSzgiqyZxLbrHK7LvGAXVn547m4sgXqRpYqSOgg8RZG7gBDbLA3LqSRTkWDVG/yRAFAnRtpE4MH6aGLWbKy5cdttsVZs2tuZkhr0mZvJ53M7rB+1UUitz+OS7B0XLIPwzKfgpZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fQsmNBxL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fQsmNBxL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B7A01F00893; Thu, 11 Jun 2026 17:31:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781199064; bh=tgsmiHSdX46c0MwHeH/XSmXB4qm5+uLMh56BNRp2GbI=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=fQsmNBxLkvs0d98A8GPz/squQVksBCxzDcr942/lZd1FXkHDEzUBRhSzt2ZV4Hnpx IJEiEWYSiwd9ljMAVQn+V1YB7PKiIgvnoklZhQIoQpix0Xi6qUTyu36UdPHzzouBXl pA7FZ8lOVZxdbIL0bs+osaw0ppxOcP5uhIy1rBj1SUdXuhGofofpZgP2dXMQLsjo27 nPK0c60CjYebkCuH4DYQb3KPEWRQGJfEsRgNpKVFO/COM6NPIw3kyjowYQXJvQUZ3z EQXgpUxglytB/kd4/yUkqiEXxz6a2J15eeR7ErPhQqjnVLtCkyC89KQXYB6cZivmw0 iNUZpgmohfRww== Message-ID: <7e5031b94df2e3d7fa977ee06242c1cd5c4db497.camel@kernel.org> Subject: Re: [PATCH] NFS: fix refcount leak in nfs_direct_write_schedule_iovec() From: Trond Myklebust To: WenTao Liang , anna@kernel.org Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Date: Thu, 11 Jun 2026 13:31:03 -0400 In-Reply-To: <20260611150354.90801-1-vulab@iscas.ac.cn> References: <20260611150354.90801-1-vulab@iscas.ac.cn> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2026-06-11 at 23:03 +0800, WenTao Liang wrote: > When nfs_direct_write_schedule_iovec() fails to start any write > operations (requested_bytes =3D=3D 0), it bails out after calling > inode_dio_end() but before releasing the dreq->io_count reference > that was unconditionally acquired by get_dreq().=C2=A0 The normal > success path balances that via put_dreq(), which decrements the > io_count and eventually calls nfs_direct_write_complete().=C2=A0 The > leaked reference prevents proper cleanup of the direct write request. Again, I'd like you to explain this claim that somehow io_count is preventing cleanup of the request. Neither nfs_file_direct_write nor nfs_direct_req_release care about its value. >=20 > Add the missing put_dreq() in the early exit path before calling > nfs_direct_req_release(). >=20 > Cc: stable@vger.kernel.org > Fixes: 65caafd0d214 ("SUNRPC reverting d03727b248d0 ("NFSv4 fix CLOSE > not waiting for direct IO compeletion")") > Signed-off-by: WenTao Liang > --- > =C2=A0fs/nfs/direct.c | 1 + > =C2=A01 file changed, 1 insertion(+) >=20 > diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c > index 41a6cabb0592..99bd72a4601c 100644 > --- a/fs/nfs/direct.c > +++ b/fs/nfs/direct.c > @@ -956,6 +956,7 @@ static ssize_t > nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 */ > =C2=A0 if (requested_bytes =3D=3D 0) { > =C2=A0 inode_dio_end(inode); > + put_dreq(dreq); > =C2=A0 nfs_direct_req_release(dreq); > =C2=A0 return result < 0 ? result : -EIO; > =C2=A0 } --=20 Trond Myklebust Linux NFS client maintainer, Hammerspace trondmy@kernel.org, trond.myklebust@hammerspace.com