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Subject[PATCH][next][V2] media: vivid: fix potential integer overflow on left shift
Date
From: Colin Ian King <colin.king@canonical.com>

There is a potential integer overflow when int 2 is left shifted
as this is evaluated using 32 bit arithmetic but is being used in
a context that expects an expression of type s64. Fix this by
shifting 2ULL to avoid a 32 bit overflow.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 8a99e9faa131 ("media: vivid: add HDMI (dis)connect RX emulation")
Fixes: 79a792dafac6 ("media: vivid: add HDMI (dis)connect TX emulation")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
V2: use intermediate variables for the shifted expression to make code
a bit more readable.
---
drivers/media/platform/vivid/vivid-ctrls.c | 24 +++++++++++-----------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/vivid/vivid-ctrls.c b/drivers/media/platform/vivid/vivid-ctrls.c
index 3e916c8befb7..df1598e81c7a 100644
--- a/drivers/media/platform/vivid/vivid-ctrls.c
+++ b/drivers/media/platform/vivid/vivid-ctrls.c
@@ -1613,6 +1613,8 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
}

if (dev->num_hdmi_inputs) {
+ s64 hdmi_input = (2ULL << (dev->num_hdmi_inputs - 1)) - 1;
+
dev->ctrl_dv_timings_signal_mode = v4l2_ctrl_new_custom(hdl_vid_cap,
&vivid_ctrl_dv_timings_signal_mode, NULL);

@@ -1633,12 +1635,13 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
V4L2_CID_DV_RX_RGB_RANGE, V4L2_DV_RGB_RANGE_FULL,
0, V4L2_DV_RGB_RANGE_AUTO);
dev->ctrl_rx_power_present = v4l2_ctrl_new_std(hdl_vid_cap,
- NULL, V4L2_CID_DV_RX_POWER_PRESENT, 0,
- (2 << (dev->num_hdmi_inputs - 1)) - 1, 0,
- (2 << (dev->num_hdmi_inputs - 1)) - 1);
+ NULL, V4L2_CID_DV_RX_POWER_PRESENT, 0, hdmi_input,
+ 0, hdmi_input);

}
if (dev->num_hdmi_outputs) {
+ s64 hdmi_output = (2ULL << (dev->num_hdmi_outputs - 1)) - 1;
+
/*
* We aren't doing anything with this at the moment, but
* HDMI outputs typically have this controls.
@@ -1652,17 +1655,14 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
dev->ctrl_display_present = v4l2_ctrl_new_custom(hdl_vid_out,
&vivid_ctrl_display_present, NULL);
dev->ctrl_tx_hotplug = v4l2_ctrl_new_std(hdl_vid_out,
- NULL, V4L2_CID_DV_TX_HOTPLUG, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1);
+ NULL, V4L2_CID_DV_TX_HOTPLUG, 0, hdmi_output,
+ 0, hdmi_output);
dev->ctrl_tx_rxsense = v4l2_ctrl_new_std(hdl_vid_out,
- NULL, V4L2_CID_DV_TX_RXSENSE, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1);
+ NULL, V4L2_CID_DV_TX_RXSENSE, 0, hdmi_output,
+ 0, hdmi_output);
dev->ctrl_tx_edid_present = v4l2_ctrl_new_std(hdl_vid_out,
- NULL, V4L2_CID_DV_TX_EDID_PRESENT, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1, 0,
- (2 << (dev->num_hdmi_outputs - 1)) - 1);
+ NULL, V4L2_CID_DV_TX_EDID_PRESENT, 0, hdmi_output,
+ 0, hdmi_output);
}
if ((dev->has_vid_cap && dev->has_vid_out) ||
(dev->has_vbi_cap && dev->has_vbi_out))
--
2.20.1
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