From c9e8440eca61298ecccbb27f53036124a7a3c6c8 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Tue, 4 Feb 2014 16:08:38 -0800 Subject: [PATCH] staging: ion: Fix overflow and list bugs in system heap Fix a few bugs in ion_system_heap: Initialize the list node in the info block. Don't store size_remaining in a signed long, allocating >2GB could overflow, resulting in a call to sg_alloc_table with nents=0 which panics. alloc_largest_available will never return a block larger than size_remanining, so it can never go negative. Limit a single allocation to half of all memory. Prevents a large allocation from taking down the whole system. Cc: Colin Cross Cc: Android Kernel Team Signed-off-by: Colin Cross [jstultz: Minor commit subject tweak] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/ion_system_heap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c index 7f0729130d65..9849f3963e75 100644 --- a/drivers/staging/android/ion/ion_system_heap.c +++ b/drivers/staging/android/ion/ion_system_heap.c @@ -124,6 +124,7 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap, info->page = page; info->order = orders[i]; + INIT_LIST_HEAD(&info->list); return info; } kfree(info); @@ -145,12 +146,15 @@ static int ion_system_heap_allocate(struct ion_heap *heap, struct list_head pages; struct page_info *info, *tmp_info; int i = 0; - long size_remaining = PAGE_ALIGN(size); + unsigned long size_remaining = PAGE_ALIGN(size); unsigned int max_order = orders[0]; if (align > PAGE_SIZE) return -EINVAL; + if (size / PAGE_SIZE > totalram_pages / 2) + return -ENOMEM; + INIT_LIST_HEAD(&pages); while (size_remaining > 0) { info = alloc_largest_available(sys_heap, buffer, size_remaining, -- 2.39.5