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 82FDD13F426; Sun, 24 Mar 2024 23:10:04 +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=1711321805; cv=none; b=OwTftL2Z3+fYpL9bt8kUUT0FI3tDR3POVc3smbU7AEip1QNiszoDZx/Ni2V7PCYo/lfJoga4GGcvC9kenICo5XVPnZYKofPEohN1zcvv4hyYC0VDRRN/FeiV70U3CY3Li/Hwag9RYCcZOOCVbvZLOY5cEwrLvnbAXNtREcsqAzE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321805; c=relaxed/simple; bh=g1ekMzSm4txgtotmTsA3S1y1NJqyvLL1l8D4Mk/0VZ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MOLGKQBsy3UHbsxxNfWu/5e/rMtS0qeJuPeEcvLksVAseXcWsF6rgtZUmql8jhVr0hyR032DhhlUsDnpx/SpVDHtDyra6UXaF7wzophlBQ3R2NDP2FEZ008w+wARYjMHFfVYk1lOoLoiTc75AzDeETyXzLgUlCYnV0QnHf4OaOI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cv++eqOe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Cv++eqOe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93EEBC43390; Sun, 24 Mar 2024 23:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321804; bh=g1ekMzSm4txgtotmTsA3S1y1NJqyvLL1l8D4Mk/0VZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cv++eqOefZVbCieB+kFo7c6m5Rd/MNI2qx2dzj2zVLCY1+odL7oPn/0Swu0Vk5N/l jpeqStrqJrFefoOXklAkf7nC9jUiqY9e/Fh38dOfDomd+IdmMUA+VI4aZ6kEOmJZ/B iMQehtdIn4LbhXiH/jTnzaacwRcsKBaoFRCRnf2Z32mS4neQ74C2Q7azfI88CcVsx1 a4zL7CZgDXqffHtrtFGjsE4nlsQCD3n39u8mVTYas72Rrm7lEiwXsa1cY4+IiF0TgA u2GdOG6swdZvX/yzO2+8L+kEW4FgUos2WXVfLoWX/Xyu5RIxk/wSwHsSGgntjgRSuG Ra2TfqSlg6obw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jorge Mora , Jorge Mora , Benjamin Coddington , Trond Myklebust , Sasha Levin Subject: [PATCH 6.6 532/638] NFSv4.2: fix listxattr maximum XDR buffer size Date: Sun, 24 Mar 2024 18:59:29 -0400 Message-ID: <20240324230116.1348576-533-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324230116.1348576-1-sashal@kernel.org> References: <20240324230116.1348576-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Jorge Mora [ Upstream commit bcac8bff90a6ee1629f90669cdb9d28fb86049b0 ] Switch order of operations to avoid creating a short XDR buffer: e.g., buflen = 12, old xdrlen = 12, new xdrlen = 20. Having a short XDR buffer leads to lxa_maxcount be a few bytes less than what is needed to retrieve the whole list when using a buflen as returned by a call with size = 0: buflen = listxattr(path, NULL, 0); buf = malloc(buflen); buflen = listxattr(path, buf, buflen); For a file with one attribute (name = '123456'), the first call with size = 0 will return buflen = 12 ('user.123456\x00'). The second call with size = 12, sends LISTXATTRS with lxa_maxcount = 12 + 8 (cookie) + 4 (array count) = 24. The XDR buffer needs 8 (cookie) + 4 (array count) + 4 (name count) + 6 (name len) + 2 (padding) + 4 (eof) = 28 which is 4 bytes shorter than the lxa_maxcount provided in the call. Fixes: 04a5da690e8f ("NFSv4.2: define limits and sizes for user xattr handling") Signed-off-by: Jorge Mora Reviewed-by: Benjamin Coddington Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs42.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h index b59876b01a1e3..0282d93c8bccb 100644 --- a/fs/nfs/nfs42.h +++ b/fs/nfs/nfs42.h @@ -55,11 +55,14 @@ int nfs42_proc_removexattr(struct inode *inode, const char *name); * They would be 7 bytes long in the eventual buffer ("user.x\0"), and * 8 bytes long XDR-encoded. * - * Include the trailing eof word as well. + * Include the trailing eof word as well and make the result a multiple + * of 4 bytes. */ static inline u32 nfs42_listxattr_xdrsize(u32 buflen) { - return ((buflen / (XATTR_USER_PREFIX_LEN + 2)) * 8) + 4; + u32 size = 8 * buflen / (XATTR_USER_PREFIX_LEN + 2) + 4; + + return (size + 3) & ~3; } #endif /* CONFIG_NFS_V4_2 */ #endif /* __LINUX_FS_NFS_NFS4_2_H */ -- 2.43.0