From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225ztNmZqgXF1qL+akf9Bt6QsBSev/u+Cu63N8XQ4Vo+U7aYEH43pvbhMP9gDYL/ocbV5R08 ARC-Seal: i=1; a=rsa-sha256; t=1517256790; cv=none; d=google.com; s=arc-20160816; b=C6hLPBPUAGJkGbYzdDOJRmVrIyBaP4QCy012gdwhuEu8Ngx3uUFVvXu4sGgqSx3HI/ 89hSNOp931+NX6pAzlBwV42Z/XZUlEcHMUAf4aZszi+Eg8hXF3QqHWvJD7NG0IQ4NnJW lpeBAiVx4o9NpfheUMOBua/PULF0RqwglyAdnOqhjnklZoWZ6bcJ6DWtsgx3uKbY/0oe HmwOp5qF1RijSw9AbUcXU1CI1DKS1TeEjtoMJD+/FnQEcYHGBuBB4VVlWfvDTP1DZLaU qwsCEPTdIG6LHxgkY1pTWv5vBJ9V5hIdvBnTKFkJ7OfpSshcuyXgt99VDNQighSSF0Vu pcuA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=chwAdS50v2DH2x+6YQiedD3dBPKbSLWn96pb4e6AXzk=; b=eGhGA7D9NJxAwUYKtA64Gom8TxR2ibaOFfo1s5JFDceDPw93VpfYKgNO9/SWFNFDam /z8tRK7+j/CyFdSarAnHwjW7m+XYZbQnELnIQDEsrH1dhWNbcoIXP4YmRzJTMFkiRZOu 8sa9CKwtuyXJP/EID2oNMLeOfSKxSADWZgfMZEY1O1QIXf/SR8+fuG5b7GbFrHpuYBKy 5jxTWz5Pua4ZCYWwJW1UHKLgHCkUa6whGIe5KUE1U30sPX/1JeC+VonrpmMXAfycrmXu +DN4MoyeaCyFCAJzW/qaYf+gGp3EXQGwwnOMiTltDtY47TxzXWP84+wfp/A34JBSmRqz MMRg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+03bee3680a37466775e7@syzkaller.appspotmail.com, Xin Long , David Ahern , "David S. Miller" Subject: [PATCH 4.14 53/71] netlink: reset extack earlier in netlink_rcv_skb Date: Mon, 29 Jan 2018 13:57:21 +0100 Message-Id: <20180129123830.966443643@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180129123827.271171825@linuxfoundation.org> References: <20180129123827.271171825@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1590959056106083456?= X-GMAIL-MSGID: =?utf-8?q?1590959056106083456?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit cd443f1e91ca600a092e780e8250cd6a2954b763 ] Move up the extack reset/initialization in netlink_rcv_skb, so that those 'goto ack' will not skip it. Otherwise, later on netlink_ack may use the uninitialized extack and cause kernel crash. Fixes: cbbdf8433a5f ("netlink: extack needs to be reset each time through loop") Reported-by: syzbot+03bee3680a37466775e7@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2400,6 +2400,7 @@ int netlink_rcv_skb(struct sk_buff *skb, while (skb->len >= nlmsg_total_size(0)) { int msglen; + memset(&extack, 0, sizeof(extack)); nlh = nlmsg_hdr(skb); err = 0; @@ -2414,7 +2415,6 @@ int netlink_rcv_skb(struct sk_buff *skb, if (nlh->nlmsg_type < NLMSG_MIN_TYPE) goto ack; - memset(&extack, 0, sizeof(extack)); err = cb(skb, nlh, &extack); if (err == -EINTR) goto skip;