From 2490cdf6435b1d3cac0dbf710cd752487c67c296 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 6 Jan 2018 12:22:30 +0300 Subject: [PATCH] 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. Fixes: 033ddf12bcf5 ("tee: add register user memory") Signed-off-by: Dan Carpenter Signed-off-by: Jens Wiklander --- drivers/tee/tee_shm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 6f36da9ee412..556960a1bab3 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -283,7 +283,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, 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;