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authorPrashant Malani <pmalani@chromium.org>2019-08-24 11:36:19 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-21 08:17:00 +0300
commit688fdaa54a3e985d83de83bdf98433b5ae2e358f (patch)
tree822ba0cd8a5be95a4c4f6dfab015350cdccc9069
parentd9f79f0ace550f450851a5c07f88eed585b46214 (diff)
downloadlinux-688fdaa54a3e985d83de83bdf98433b5ae2e358f.tar.xz
r8152: Set memory to all 0xFFs on failed reg reads
[ 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>
-rw-r--r--drivers/net/usb/r8152.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index f1b5201cc320..a065a6184f7e 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;