virt_addr_valid() could be insufficient to validate the virt addr on some architecture, which could lead to potential BUG which has been found on arm64/powerpc64. Let's add WARN_ON to check if the virt addr is passed virt_addr_valid() but is a vmalloc/module address. Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> --- mm/usercopy.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/usercopy.c b/mm/usercopy.c index b3de3c4eefba..ce83e0b137dd 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -228,6 +228,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, if (!virt_addr_valid(ptr)) return; + WARN_ON_ONCE(is_vmalloc_or_module_addr(ptr)); + /* * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the * highmem page or fallback to virt_to_page(). The following -- 2.26.2
