[ 037/175] USB: ums_realtek: do not use stack memory for DMA in __do_config_autodelink
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-03-30 21:56:45
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3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Boyer <redacted> commit 4898e07174b79013afd2b422ef6c4336ef8e6783 upstream. __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 <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/storage/realtek_cr.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/usb/storage/realtek_cr.c
+++ b/drivers/usb/storage/realtek_cr.c@@ -507,9 +507,14 @@ static int __do_config_autodelink(struct { 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 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; }