From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Prashant Malani <pmalani@chromium.org>,
Hayes Wang <hayeswang@realtek.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
linux-usb@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 13/27] r8152: Set memory to all 0xFFs on failed reg reads
Date: Wed, 4 Sep 2019 12:02:06 -0400 [thread overview]
Message-ID: <20190904160220.4545-13-sashal@kernel.org> (raw)
In-Reply-To: <20190904160220.4545-1-sashal@kernel.org>
From: Prashant Malani <pmalani@chromium.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@chromium.org>
Acked-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.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 02e29562d254e..15dc70c118579 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -689,8 +689,11 @@ 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
parent reply other threads:[~2019-09-04 16:05 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20190904160220.4545-1-sashal@kernel.org>]
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