On Mon, 25 May 2015, Jani Nikula jani.nikula@linux.intel.com wrote:
On Mon, 25 May 2015, Andrey Ryabinin a.ryabinin@samsung.com wrote:
On 05/25/2015 04:12 PM, Jani Nikula wrote:
On Mon, 25 May 2015, Andrey Ryabinin a.ryabinin@samsung.com wrote:
for_each_*_in_state validate array index after access to array elements, thus perform out of bounds read.
Fix this by validating index in the first place and read array element iff validation was successful.
Fixes: df63b9994eaf ("drm/atomic: Add for_each_{connector,crtc,plane}_in_state helper macros") Signed-off-by: Andrey Ryabinin a.ryabinin@samsung.com
include/drm/drm_atomic.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index c1571034..3f13b91 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -77,26 +77,26 @@ int __must_check drm_atomic_async_commit(struct drm_atomic_state *state);
#define for_each_connector_in_state(state, connector, connector_state, __i) \ for ((__i) = 0; \
(connector) = (state)->connectors[__i], \(connector_state) = (state)->connector_states[__i], \(__i) < (state)->num_connector; \
(__i) < (state)->num_connector && \((connector) = (state)->connectors[__i], \(connector_state) = (state)->connector_states[__i], 1); \This will stop at the first NULL connector/connector_state. Similarly for the loops below.
This will stop iff (__i) >= (state)->num_connector, because the result of expression: ((connector) = (state)->connectors[__i], (connector_state) = (state)->connector_states[__i], 1) is always 1.
Why do you think it'll always be 1?
That might be because there's the 1 at the end. *blush*.
I do wonder if this is too subtle in general, or if it's just too subtle for me.
BR, Jani.
BR, Jani.
-- Jani Nikula, Intel Open Source Technology Center