On Wed, Jun 12, 2024 at 05:13:39PM +0800, David Gow wrote: > On Tue, 11 Jun 2024 at 05:33, Kees Cook <kees@xxxxxxxxxx> wrote: > > > > Convert the runtime tests of hardened usercopy to standard KUnit tests. > > > > Co-developed-by: Vitor Massaru Iha <vitor@xxxxxxxxxxx> > > Signed-off-by: Vitor Massaru Iha <vitor@xxxxxxxxxxx> > > Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@xxxxxxxxxxx > > Tested-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx> > > Signed-off-by: Kees Cook <kees@xxxxxxxxxx> > > --- > > This looks good, particularly with the x86 fix applied. > > It's still hanging on m68k -- I think at the 'illegal reversed > copy_to_user passed' test -- but I'll admit to not having tried to > debug it further. > > One other (set of) notes below about using KUNIT_EXPECT_MEMEQ_MSG(), > otherwise (assuming the m68k stuff isn't actually a regression, which > I haven't tested but I imagine is unlikely), Hi Geert, I'm trying to debug a hang on m68k in the usercopy behavioral testing routines. It's testing for the pathological case of having inverted arguments to copy_to_user(): user_addr = kunit_vm_mmap(test, NULL, 0, priv->size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, 0); ... bad_usermem = (char *)user_addr; ... KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, bad_usermem, PAGE_SIZE), 0, "illegal reversed copy_to_user passed"); On other architectures, this immediate fails because the access_ok() check rejects it. On m68k with CONFIG_ALTERNATE_USER_ADDRESS_SPACE, access_ok() short-circuits to "true". I've tried reading arch/m68k/include/asm/uaccess.h but I'm not sure what's happening under CONFIG_CPU_HAS_ADDRESS_SPACES. For now I've excluded that test for m68k, but I'm not sure what's expected to happen here on m68k for this set of bad arguments. Can you advise? Thanks! -Kees -- Kees Cook
