[PATCH v3 1/2] usb: core: Check URB setup_packet and transfer_buffer sanity

[Florian Fainelli]

Update usb_hcd_map_urb_for_dma() to check for an URB's setup_packet and
transfer_buffer sanity. We first check that urb->setup_packet is neither
coming from vmalloc space nor is an on stack buffer, and if that's the
case, produce a warning and return an error. For urb->transfer_buffer
there is an existing is_vmalloc_addr() check so we just supplement that
with an object_is_on_stack() check, produce a warning if that is the case
and also return an error.

Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
 drivers/usb/core/hcd.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 49550790a3cb..26d710eec7da 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/version.h>
 #include <linux/kernel.h>
+#include <linux/sched/task_stack.h>
 #include <linux/slab.h>
 #include <linux/completion.h>
 #include <linux/utsname.h>
@@ -1523,6 +1524,14 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 		if (hcd->self.uses_pio_for_control)
 			return ret;
 		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
+			if (is_vmalloc_addr(urb->setup_packet)) {
+				WARN_ONCE(1, "setup packet is not dma capable\n");
+				return -EAGAIN;
+			} else if (object_is_on_stack(urb->setup_packet)) {
+				WARN_ONCE(1, "setup packet is on stack\n");
+				return -EAGAIN;
+			}
+
 			urb->setup_dma = dma_map_single(
 					hcd->self.sysdev,
 					urb->setup_packet,
@@ -1587,6 +1596,9 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 			} else if (is_vmalloc_addr(urb->transfer_buffer)) {
 				WARN_ONCE(1, "transfer buffer not dma capable\n");
 				ret = -EAGAIN;
+			} else if (object_is_on_stack(urb->transfer_buffer)) {
+				WARN_ONCE(1, "transfer buffer is on stack\n");
+				ret = -EAGAIN;
 			} else {
 				urb->transfer_dma = dma_map_single(
 						hcd->self.sysdev,
-- 
2.9.3