From: Liviu Dudau <li...@dudau.co.uk> commit 6ade20327dbb808882888ed8ccded71e93067cf9 upstream.
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-li...@dudau.co.uk Fixes: f3c01d2f3ade ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: Liviu Dudau <li...@dudau.co.uk> Reviewed-by: Andrew Morton <a...@linux-foundation.org> Cc: Chintan Pandya <cpan...@codeaurora.org> Cc: Andrey Ryabinin <aryabi...@virtuozzo.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Cc: Guenter Roeck <li...@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1524,7 +1524,7 @@ static void __vunmap(const void *addr, i 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);