On Mon, Jun 03, 2019 at 06:55:16PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > tee_shm_register()->optee_shm_unregister()->check_mem_type() uses provided > user pointers for vma lookups (via __check_mem_type()), which can only by > done with untagged pointers. > > Untag user pointers in this function. > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> "tee: shm: untag user pointers in tee_shm_register" Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees > --- > drivers/tee/tee_shm.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index 49fd7312e2aa..96945f4cefb8 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -263,6 +263,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > shm->teedev = teedev; > shm->ctx = ctx; > shm->id = -1; > + addr = untagged_addr(addr); > start = rounddown(addr, PAGE_SIZE); > shm->offset = addr - start; > shm->size = length; > -- > 2.22.0.rc1.311.g5d7573a151-goog > -- Kees Cook
