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 801596FA0 for ; Mon, 16 Jan 2023 17:04:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 047CDC433EF; Mon, 16 Jan 2023 17:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673888658; bh=Vc4v8h4MbMMysvq5oMdCkdG6Yi5MZQtRJf3f93Qa7G0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ft7iPYrbqx3LdbceoTgE2u8OzAKZtsfp0XsTKjhX+N8LVdGDa2+EqzLXN/Jqby7eP YNrrri+6IqjKaXSHQjvFZ1adpctajyYUu6Xgb3nUb5h76MORVRXsQd7GdmMYXCQ8P6 ZzvpqgamVjzBMHkpicNC529iKRwwziFTpAAnJBRc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Trond Myklebust , Sasha Levin Subject: [PATCH 4.14 090/338] NFSv4.2: Fix a memory stomp in decode_attr_security_label Date: Mon, 16 Jan 2023 16:49:23 +0100 Message-Id: <20230116154824.808524246@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154820.689115727@linuxfoundation.org> References: <20230116154820.689115727@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Trond Myklebust [ Upstream commit 43c1031f7110967c240cb6e922adcfc4b8899183 ] We must not change the value of label->len if it is zero, since that indicates we stored a label. Fixes: b4487b935452 ("nfs: Fix getxattr kernel panic and memory overflow") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4xdr.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index ccdc0ca699c3..e604c0e02f4d 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -4255,12 +4255,10 @@ static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap, if (unlikely(!p)) goto out_overflow; if (len < NFS4_MAXLABELLEN) { - if (label) { - if (label->len) { - if (label->len < len) - return -ERANGE; - memcpy(label->label, p, len); - } + if (label && label->len) { + if (label->len < len) + return -ERANGE; + memcpy(label->label, p, len); label->len = len; label->pi = pi; label->lfs = lfs; -- 2.35.1