From 60e11dfc002962181fe4f0db54b33c65fee02c52 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 16 Dec 2013 21:07:52 -0800 Subject: [PATCH] staging: ion: Fix possible null pointer dereference The kbuild test robot reported: drivers/staging/android/ion/ion_system_heap.c:122 alloc_largest_available() error: potential null dereference 'info'. (kmalloc returns null) Where the pointer returned from kmalloc goes unchecked for failure. This patch checks the return for NULL, and reworks the logic, as suggested by Colin, so we allocate the page_info structure first. Acked-by: Colin Cross Cc: Android Kernel Team Reported-by: kbuild test robot Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/ion_system_heap.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c index 05e9dc93980f..5bccf9e2c93c 100644 --- a/drivers/staging/android/ion/ion_system_heap.c +++ b/drivers/staging/android/ion/ion_system_heap.c @@ -108,6 +108,10 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap, struct page_info *info; int i; + info = kmalloc(sizeof(struct page_info), GFP_KERNEL); + if (!info) + return NULL; + for (i = 0; i < num_orders; i++) { if (size < order_to_size(orders[i])) continue; @@ -118,11 +122,12 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap, if (!page) continue; - info = kmalloc(sizeof(struct page_info), GFP_KERNEL); info->page = page; info->order = orders[i]; return info; } + kfree(info); + return NULL; } -- 2.34.1