From: Kees Cook <keescook@xxxxxxxxxxxx> Subject: lib/test_overflow.c: avoid tainting the kernel and fix wrap size This adds __GFP_NOWARN to the kmalloc()-portions of the overflow test to avoid tainting the kernel. Additionally fixes up the math on wrap size to be architecture and page size agnostic. Link: http://lkml.kernel.org/r/201905282012.0A8767E24@keescook Fixes: ca90800a91ba ("test_overflow: Add memory allocation overflow tests") Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Suggested-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/test_overflow.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/lib/test_overflow.c~lib-test_overflow-avoid-tainting-the-kernel-and-fix-wrap-size +++ a/lib/test_overflow.c @@ -486,16 +486,17 @@ static int __init test_overflow_shift(vo * Deal with the various forms of allocator arguments. See comments above * the DEFINE_TEST_ALLOC() instances for mapping of the "bits". */ -#define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL) -#define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE) +#define alloc_GFP (GFP_KERNEL | __GFP_NOWARN) +#define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP) +#define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE) #define alloc000(alloc, arg, sz) alloc(sz) #define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE) -#define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL) +#define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP) #define free0(free, arg, ptr) free(ptr) #define free1(free, arg, ptr) free(arg, ptr) -/* Wrap around to 8K */ -#define TEST_SIZE (9 << PAGE_SHIFT) +/* Wrap around to 16K */ +#define TEST_SIZE (5 * 4096) #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\ static int __init test_ ## func (void *arg) \ _
