From 4898e07174b79013afd2b422ef6c4336ef8e6783 Mon Sep 17 00:00:00 2001 From: "jwboyer@redhat.com" Date: Mon, 20 Feb 2012 15:34:34 -0500 Subject: [PATCH] USB: ums_realtek: do not use stack memory for DMA in __do_config_autodelink __do_config_autodelink passes the data variable to the transport function. If the calling functions pass a stack variable, this will eventually trigger a DMA-API debug backtrace for mapping stack memory in the DMA buffer. Fix this by calling kmemdup for the passed data instead. Signed-off-by: Josh Boyer Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/realtek_cr.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c index b1c2fe8b6dcd..84a4bc0cbee4 100644 --- a/drivers/usb/storage/realtek_cr.c +++ b/drivers/usb/storage/realtek_cr.c @@ -507,9 +507,14 @@ static int __do_config_autodelink(struct us_data *us, u8 *data, u16 len) { int retval; u8 cmnd[12] = {0}; + u8 *buf; US_DEBUGP("%s, addr = 0xfe47, len = %d\n", __FUNCTION__, len); + buf = kmemdup(data, len, GFP_NOIO); + if (!buf) + return USB_STOR_TRANSPORT_ERROR; + cmnd[0] = 0xF0; cmnd[1] = 0x0E; cmnd[2] = 0xfe; @@ -517,7 +522,8 @@ static int __do_config_autodelink(struct us_data *us, u8 *data, u16 len) cmnd[4] = (u8)(len >> 8); cmnd[5] = (u8)len; - retval = rts51x_bulk_transport_special(us, 0, cmnd, 12, data, len, DMA_TO_DEVICE, NULL); + retval = rts51x_bulk_transport_special(us, 0, cmnd, 12, buf, len, DMA_TO_DEVICE, NULL); + kfree(buf); if (retval != USB_STOR_TRANSPORT_GOOD) { return -EIO; } -- 2.20.1