From f4ea823be2ca9e61522de002804c9a7a54c9be16 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 144b22727505..7f0729130d65 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; } -- 2.20.1