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authorYannick Fertré <yannick.fertre@st.com>2019-04-03 12:20:16 +0300
committerBenjamin Gaignard <benjamin.gaignard@linaro.org>2019-04-24 14:52:06 +0300
commit77756ad6d08fb3f276d357be4c318f871dab8734 (patch)
treede84d976d1f6d8b398d73bc486ba1deb4da317ef /drivers
parent8ceb8568d6e8d53dc000a9eeacd47c8f298c38f0 (diff)
downloadlinux-77756ad6d08fb3f276d357be4c318f871dab8734.tar.xz
drm/stm: ltdc: limit number of layer to avoid memory overflow
If the number of layer is greater than LTDC_MAX_LAYER, we can have memory overflow when reading plane_fpsi[]. Signed-off-by: Yannick Fertré <yannick.fertre@st.com> Acked-by: Philippe Cornu <philippe.cornu@st.com> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/1554283216-2700-1-git-send-email-yannick.fertre@st.com
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/stm/ltdc.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index cde2f18ce1c1..17438c28d9fc 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1021,10 +1021,13 @@ static int ltdc_get_caps(struct drm_device *ddev)
struct ltdc_device *ldev = ddev->dev_private;
u32 bus_width_log2, lcr, gc2r;
- /* at least 1 layer must be managed */
+ /*
+ * at least 1 layer must be managed & the number of layers
+ * must not exceed LTDC_MAX_LAYER
+ */
lcr = reg_read(ldev->regs, LTDC_LCR);
- ldev->caps.nb_layers = max_t(int, lcr, 1);
+ ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
/* set data bus width */
gc2r = reg_read(ldev->regs, LTDC_GC2R);