linux-kernel - [PATCH 4.19 45/79] r8152: Set memory to all 0xFFs on failed reg reads

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190919214811.597277687@linuxfoundation.org>
Date:   Fri, 20 Sep 2019 00:03:30 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Prashant Malani <pmalani@...omium.org>,
        Hayes Wang <hayeswang@...ltek.com>,
        "David S. Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 45/79] r8152: Set memory to all 0xFFs on failed reg reads

From: Prashant Malani <pmalani@...omium.org>

[ Upstream commit f53a7ad189594a112167efaf17ea8d0242b5ac00 ]

get_registers() blindly copies the memory written to by the
usb_control_msg() call even if the underlying urb failed.

This could lead to junk register values being read by the driver, since
some indirect callers of get_registers() ignore the return values. One
example is:
  ocp_read_dword() ignores the return value of generic_ocp_read(), which
  calls get_registers().

So, emulate PCI "Master Abort" behavior by setting the buffer to all
0xFFs when usb_control_msg() fails.

This patch is copied from the r8152 driver (v2.12.0) published by
Realtek (www.realtek.com).

Signed-off-by: Prashant Malani <pmalani@...omium.org>
Acked-by: Hayes Wang <hayeswang@...ltek.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/usb/r8152.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index f1b5201cc3207..a065a6184f7e4 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -788,8 +788,11 @@ int get_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data)
 	ret = usb_control_msg(tp->udev, usb_rcvctrlpipe(tp->udev, 0),
 			      RTL8152_REQ_GET_REGS, RTL8152_REQT_READ,
 			      value, index, tmp, size, 500);
+	if (ret < 0)
+		memset(data, 0xff, size);
+	else
+		memcpy(data, tmp, size);
 
-	memcpy(data, tmp, size);
 	kfree(tmp);
 
 	return ret;
-- 
2.20.1