| From | Ben Hutchings <> | Date | Thu, 11 Sep 2014 13:32:13 +0100 | Subject | [PATCH 3.2 084/131] USB: whiteheat: Added bounds checking for bulk command response |
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3.2.63-rc1 review patch. If anyone has any objections, please let me know.
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From: James Forshaw <forshaw@google.com>
commit 6817ae225cd650fb1c3295d769298c38b1eba818 upstream.
This patch fixes a potential security issue in the whiteheat USB driver which might allow a local attacker to cause kernel memory corrpution. This is due to an unchecked memcpy into a fixed size buffer (of 64 bytes). On EHCI and XHCI busses it's possible to craft responses greater than 64 bytes leading a buffer overflow.
Signed-off-by: James Forshaw <forshaw@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/usb/serial/whiteheat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/usb/serial/whiteheat.c +++ b/drivers/usb/serial/whiteheat.c @@ -1006,6 +1006,10 @@ static void command_port_read_callback(s dbg("%s - command_info is NULL, exiting.", __func__); return; } + if (!urb->actual_length) { + dev_dbg(&urb->dev->dev, "%s - empty response, exiting.\n", __func__); + return; + } if (status) { dbg("%s - nonzero urb status: %d", __func__, status); if (status != -ENOENT) @@ -1027,7 +1031,8 @@ static void command_port_read_callback(s /* These are unsolicited reports from the firmware, hence no waiting command to wakeup */ dbg("%s - event received", __func__); - } else if (data[0] == WHITEHEAT_GET_DTR_RTS) { + } else if ((data[0] == WHITEHEAT_GET_DTR_RTS) && + (urb->actual_length - 1 <= sizeof(command_info->result_buffer))) { memcpy(command_info->result_buffer, &data[1], urb->actual_length - 1); command_info->command_finished = WHITEHEAT_CMD_COMPLETE;
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