Re: [PATCH v16 14/16] tee, arm64: untag user pointers in tee_shm_register
From: Kees Cook <hidden>
Date: 2019-06-08 04:05:06
Also in:
amd-gfx, dri-devel, kvm, linux-kselftest, linux-media, linux-mm, linux-rdma, lkml
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 <redacted>
"tee: shm: untag user pointers in tee_shm_register" Reviewed-by: Kees Cook <redacted> -Kees
quoted hunk ↗ jump to hunk
--- 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
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