2020-02-27 16:20:47

by Dan Carpenter

Subject: [PATCH] tee: amdtee: out of bounds read in find_session()

The "index" is a user provided value from 0-USHRT_MAX. If it's over
TEE_NUM_SESSIONS (31) then it results in an out of bounds read when we
call test_bit(index, sess->sess_mask).

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Signed-off-by: Dan Carpenter <[email protected]>
---
drivers/tee/amdtee/core.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
index 6370bb55f512..dbc238c7c263 100644
--- a/drivers/tee/amdtee/core.c
+++ b/drivers/tee/amdtee/core.c
@@ -139,6 +139,9 @@ static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
u32 index = get_session_index(session);
struct amdtee_session *sess;

+ if (index >= TEE_NUM_SESSIONS)
+ return NULL;
+
list_for_each_entry(sess, &ctxdata->sess_list, list_node)
if (ta_handle == sess->ta_handle &&
test_bit(index, sess->sess_mask))
--
2.11.0

2020-03-10 06:23:18

by Rijo Thomas

Subject: Re: [PATCH] tee: amdtee: out of bounds read in find_session()

On 27/02/20 9:49 pm, Dan Carpenter wrote:
> The "index" is a user provided value from 0-USHRT_MAX. If it's over
> TEE_NUM_SESSIONS (31) then it results in an out of bounds read when we
> call test_bit(index, sess->sess_mask).
>
> Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
> Signed-off-by: Dan Carpenter <[email protected]>

Acked-by: Rijo Thomas <[email protected]>

Thanks,
Rijo

> ---
> drivers/tee/amdtee/core.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
> index 6370bb55f512..dbc238c7c263 100644
> --- a/drivers/tee/amdtee/core.c
> +++ b/drivers/tee/amdtee/core.c
> @@ -139,6 +139,9 @@ static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
> u32 index = get_session_index(session);
> struct amdtee_session *sess;
>
> + if (index >= TEE_NUM_SESSIONS)
> + return NULL;
> +
> list_for_each_entry(sess, &ctxdata->sess_list, list_node)
> if (ta_handle == sess->ta_handle &&
> test_bit(index, sess->sess_mask))
>