[078/264] ums_realtek: do not use stack memory for DMA
From: Greg KH <gregkh@suse.de>
Date: 2011-11-10 03:38:55
Also in:
lkml
3.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adam Cozzette <redacted> commit 065e60964e293227e4feb0c1f7e27e609316ed9a upstream. This patch changes rts51x_read_mem, rts51x_write_mem, and rts51x_read_status to allocate temporary buffers with kmalloc. This way stack addresses are not used for DMA when these functions call rts51x_bulk_transport. Signed-off-by: Adam Cozzette <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/usb/storage/realtek_cr.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-)
--- a/drivers/usb/storage/realtek_cr.c
+++ b/drivers/usb/storage/realtek_cr.c@@ -320,6 +320,11 @@ static int rts51x_read_mem(struct us_dat { int retval; u8 cmnd[12] = { 0 }; + u8 *buf; + + buf = kmalloc(len, GFP_NOIO); + if (buf == NULL) + return USB_STOR_TRANSPORT_ERROR; US_DEBUGP("%s, addr = 0x%x, len = %d\n", __func__, addr, len);
@@ -331,10 +336,14 @@ static int rts51x_read_mem(struct us_dat cmnd[5] = (u8) len; retval = rts51x_bulk_transport(us, 0, cmnd, 12, - data, len, DMA_FROM_DEVICE, NULL); - if (retval != USB_STOR_TRANSPORT_GOOD) + buf, len, DMA_FROM_DEVICE, NULL); + if (retval != USB_STOR_TRANSPORT_GOOD) { + kfree(buf); return -EIO; + } + memcpy(data, buf, len); + kfree(buf); return 0; }
@@ -342,6 +351,12 @@ static int rts51x_write_mem(struct us_da { int retval; u8 cmnd[12] = { 0 }; + u8 *buf; + + buf = kmalloc(len, GFP_NOIO); + if (buf == NULL) + return USB_STOR_TRANSPORT_ERROR; + memcpy(buf, data, len); US_DEBUGP("%s, addr = 0x%x, len = %d\n", __func__, addr, len);
@@ -353,7 +368,8 @@ static int rts51x_write_mem(struct us_da cmnd[5] = (u8) len; retval = rts51x_bulk_transport(us, 0, cmnd, 12, - data, len, DMA_TO_DEVICE, NULL); + buf, len, DMA_TO_DEVICE, NULL); + kfree(buf); if (retval != USB_STOR_TRANSPORT_GOOD) return -EIO;
@@ -365,6 +381,11 @@ static int rts51x_read_status(struct us_ { int retval; u8 cmnd[12] = { 0 }; + u8 *buf; + + buf = kmalloc(len, GFP_NOIO); + if (buf == NULL) + return USB_STOR_TRANSPORT_ERROR; US_DEBUGP("%s, lun = %d\n", __func__, lun);
@@ -372,10 +393,14 @@ static int rts51x_read_status(struct us_ cmnd[1] = 0x09; retval = rts51x_bulk_transport(us, lun, cmnd, 12, - status, len, DMA_FROM_DEVICE, actlen); - if (retval != USB_STOR_TRANSPORT_GOOD) + buf, len, DMA_FROM_DEVICE, actlen); + if (retval != USB_STOR_TRANSPORT_GOOD) { + kfree(buf); return -EIO; + } + memcpy(status, buf, len); + kfree(buf); return 0; }