[PATCH] usb: core: buffer: avoid NULL pointer dereferrence

Chunfeng Yun
2016-04-08T09:08:03Z

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

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
drivers/usb/core/buffer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 2741566..c8f958b 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -131,7 +131,7 @@ void *hcd_buffer_alloc(
}

for (i = 0; i < HCD_BUFFER_POOLS; i++) {
- if (size <= pool_max[i])
+ if (pool_max[i] && size <= pool_max[i])
return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
}
return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
@@ -158,7 +158,7 @@ void hcd_buffer_free(
}

for (i = 0; i < HCD_BUFFER_POOLS; i++) {
- if (size <= pool_max[i]) {
+ if (pool_max[i] && size <= pool_max[i]) {
dma_pool_free(hcd->pool[i], addr, dma);
return;
}
--
1.7.9.5