From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Liviu Dudau Subject: [PATCH] mm/vmalloc.c: don't dereference possible NULL pointer in __vunmap. Date: Fri, 28 Dec 2018 17:10:09 +0000 Message-Id: <20181228171009.22269-1-liviu@dudau.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: Chintan Pandya , Andrey Ryabinin , linux-mm@kvack.org, LKML , Liviu Dudau List-ID: find_vmap_area() can return a NULL pointer and we're going to dereference it without checking it first. Use the existing find_vm_area() function which does exactly what we want and checks for the NULL pointer. Fixes: f3c01d2f3ade ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: Liviu Dudau --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 871e41c55e239..806047d7fda3c 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1505,7 +1505,7 @@ static void __vunmap(const void *addr, int deallocate_pages) addr)) return; - area = find_vmap_area((unsigned long)addr)->vm; + area = find_vm_area(addr); if (unlikely(!area)) { WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr); -- 2.20.1