| Date | Fri, 30 Mar 2012 12:49:04 -0700 | From | Greg KH <> | Subject | [ 031/149] USB: ums_realtek: do not use stack memory for DMA in __do_config_autodelink |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Josh Boyer <jwboyer@redhat.com>
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 <jwboyer@redhat.com> 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 @@ -509,9 +509,14 @@ static int __do_config_autodelink(struct int retval; u16 addr = 0xFE47; u8 cmnd[12] = {0}; + u8 *buf; US_DEBUGP("%s, addr = 0x%x, len = %d\n", __FUNCTION__, addr, len); + buf = kmemdup(data, len, GFP_NOIO); + if (!buf) + return USB_STOR_TRANSPORT_ERROR; + cmnd[0] = 0xF0; cmnd[1] = 0x0E; cmnd[2] = (u8)(addr >> 8); @@ -519,7 +524,8 @@ 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; }
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