[PATCH v2 1/2] usb: core: buffer: avoid NULL pointer dereferrence

[Chunfeng Yun]

NULL pointer dereferrence will happen when class driver
wants to allocate zero length buffer and pool_max[0]
can't be used, so simply returns NULL in the case.

Signed-off-by: Chunfeng Yun 
---
 drivers/usb/core/buffer.c |3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 2741566..98e39f9 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -122,6 +122,9 @@ void *hcd_buffer_alloc(
struct usb_hcd  *hcd = bus_to_hcd(bus);
int i;
 
+   if (size == 0)
+   return NULL;
+
/* some USB hosts just use PIO */
if (!IS_ENABLED(CONFIG_HAS_DMA) ||
(!bus->controller->dma_mask &&
-- 
1.7.9.5

[PATCH v2 1/2] usb: core: buffer: avoid NULL pointer dereferrence

[Chunfeng Yun]

NULL pointer dereferrence will happen when class driver
wants to allocate zero length buffer and pool_max[0]
can't be used, so simply returns NULL in the case.

Signed-off-by: Chunfeng Yun 
---
 drivers/usb/core/buffer.c |3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 2741566..98e39f9 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -122,6 +122,9 @@ void *hcd_buffer_alloc(
struct usb_hcd  *hcd = bus_to_hcd(bus);
int i;
 
+   if (size == 0)
+   return NULL;
+
/* some USB hosts just use PIO */
if (!IS_ENABLED(CONFIG_HAS_DMA) ||
(!bus->controller->dma_mask &&
-- 
1.7.9.5