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author | Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us> | 2013-08-21 01:43:19 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2013-08-21 20:47:59 -0700 |
commit | e75dc677ff8d06ffa61bef6fee436227ae5440c6 (patch) | |
tree | 15c3d8e0ae078ae6f9b3f008c9eb3a5a9c7fc29c | |
parent | 35e57e1b49a351aa804dab6010cd46ae6112a541 (diff) | |
download | lwn-e75dc677ff8d06ffa61bef6fee436227ae5440c6.tar.gz lwn-e75dc677ff8d06ffa61bef6fee436227ae5440c6.zip |
hso: Fix stack corruption on some architectures
As Sergei Shtylyov explained in the #mipslinux IRC channel:
[Mon 2013-08-19 12:28:21 PM PDT] <headless> guys, are you sure it's not "DMA off stack" case?
[Mon 2013-08-19 12:28:35 PM PDT] <headless> it's a known stack corruptor on non-coherent arches
[Mon 2013-08-19 12:31:48 PM PDT] <DonkeyHotei> headless: for usb/ehci?
[Mon 2013-08-19 12:34:11 PM PDT] <DonkeyHotei> headless: explain
[Mon 2013-08-19 12:35:38 PM PDT] <headless> usb_control_msg() (or other such func) should not use buffer on stack. DMA from/to stack is prohibited
[Mon 2013-08-19 12:35:58 PM PDT] <headless> and EHCI uses DMA on control xfers (as well as all the others)
Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | drivers/net/usb/hso.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index 5fb36ed23c1f..86292e6aaf49 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2816,13 +2816,16 @@ exit: static int hso_get_config_data(struct usb_interface *interface) { struct usb_device *usbdev = interface_to_usbdev(interface); - u8 config_data[17]; + u8 *config_data = kmalloc(17, GFP_KERNEL); u32 if_num = interface->altsetting->desc.bInterfaceNumber; s32 result; + if (!config_data) + return -ENOMEM; if (usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x86, 0xC0, 0, 0, config_data, 17, USB_CTRL_SET_TIMEOUT) != 0x11) { + kfree(config_data); return -EIO; } @@ -2873,6 +2876,7 @@ static int hso_get_config_data(struct usb_interface *interface) if (config_data[16] & 0x1) result |= HSO_INFO_CRC_BUG; + kfree(config_data); return result; } |