From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: tee/shm: untag user pointers in tee_shm_register This patch is a part of a series that extends 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. Link: http://lkml.kernel.org/r/4b993f33196b3566ac81285ff8453219e2079b45.1563904656.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Acked-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Eric Auger <eric.auger@xxxxxxxxxx> Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx> Cc: Khalid Aziz <khalid.aziz@xxxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/tee/tee_shm.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/tee/tee_shm.c~tee-shm-untag-user-pointers-in-tee_shm_register +++ a/drivers/tee/tee_shm.c @@ -254,6 +254,7 @@ struct tee_shm *tee_shm_register(struct 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; _
