BACKPORT: tee: shm: Potential NULL dereference calling tee_shm_register()
get_user_pages_fast() can return zero in certain error paths. We should
handle that or else it means we accidentally return ERR_PTR(0) which is
NULL instead of an error pointer. The callers are not expecting that
and will crash with a NULL dereference.
Change-Id: I5622affddeb1fc5e80ba6ccdbfdc77e129a2ca84
Fixes: 033ddf12bcf5 ("tee: add register user memory")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
(cherry picked from commit 2490cdf6435b1d3cac0dbf710cd752487c67c296)
Signed-off-by: Victor Chong <victor.chong@linaro.org>
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 4f0ae2e..ed2d71c 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -283,7 +283,7 @@
if (rc > 0)
shm->num_pages = rc;
if (rc != num_pages) {
- if (rc > 0)
+ if (rc >= 0)
rc = -ENOMEM;
ret = ERR_PTR(rc);
goto err;