mm/vmalloc.c: don't dereference possible NULL pointer in __vunmap()

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.

Link: http://lkml.kernel.org/r/20181228171009.22269-1-liviu@dudau.co.uk
Fixes: f3c01d2f3a ("mm: vmalloc: avoid racy handling of debugobjects in vunmap")
Signed-off-by: Liviu Dudau <liviu@dudau.co.uk>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Liviu Dudau 2019-03-05 15:42:54 -08:00 committed by Linus Torvalds
parent abd02ac616
commit 6ade20327d
1 changed files with 1 additions and 1 deletions

View File

@ -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);