diff mbox series

[v17,13/15] tee/shm, arm64: untag user pointers in tee_shm_register

Message ID 9d68d9e7f9f89900adb4cb58c34ffe532dfb964a.1560339705.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series arm64: untag user pointers passed to the kernel | expand

Commit Message

Andrey Konovalov June 12, 2019, 11:43 a.m. UTC 
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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/tee/tee_shm.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 2da026fd12c9..09ddcd06c715 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -254,6 +254,7 @@  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;