* [PATCH] media: cx231xx: fix potential sign-extension overflow on large shift
@ 2018-10-06 18:01 ` Colin King
0 siblings, 0 replies; 2+ messages in thread
From: Colin King @ 2018-10-06 18:01 UTC (permalink / raw)
To: Mauro Carvalho Chehab, linux-media; +Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Shifting the u8 value[3] by an int can lead to sign-extension
overflow. For example, if value[3] is 0xff and the shift is 24 then it
is promoted to int and then the top bit is sign-extended so that all
upper 32 bits are set. Fix this by casting value[3] to a u32 before
the shift.
Detected by CoverityScan, CID#1016522 ("Unintended sign extension")
Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/media/usb/cx231xx/cx231xx-video.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/usb/cx231xx/cx231xx-video.c b/drivers/media/usb/cx231xx/cx231xx-video.c
index 29160df76cf7..f2f034c5cd62 100644
--- a/drivers/media/usb/cx231xx/cx231xx-video.c
+++ b/drivers/media/usb/cx231xx/cx231xx-video.c
@@ -1389,7 +1389,7 @@ int cx231xx_g_register(struct file *file, void *priv,
ret = cx231xx_read_ctrl_reg(dev, VRT_GET_REGISTER,
(u16)reg->reg, value, 4);
reg->val = value[0] | value[1] << 8 |
- value[2] << 16 | value[3] << 24;
+ value[2] << 16 | (u32)value[3] << 24;
reg->size = 4;
break;
case 1: /* AFE - read byte */
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] media: cx231xx: fix potential sign-extension overflow on large shift
@ 2018-10-06 18:01 ` Colin King
0 siblings, 0 replies; 2+ messages in thread
From: Colin King @ 2018-10-06 18:01 UTC (permalink / raw)
To: Mauro Carvalho Chehab, linux-media; +Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Shifting the u8 value[3] by an int can lead to sign-extension
overflow. For example, if value[3] is 0xff and the shift is 24 then it
is promoted to int and then the top bit is sign-extended so that all
upper 32 bits are set. Fix this by casting value[3] to a u32 before
the shift.
Detected by CoverityScan, CID#1016522 ("Unintended sign extension")
Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/media/usb/cx231xx/cx231xx-video.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/usb/cx231xx/cx231xx-video.c b/drivers/media/usb/cx231xx/cx231xx-video.c
index 29160df76cf7..f2f034c5cd62 100644
--- a/drivers/media/usb/cx231xx/cx231xx-video.c
+++ b/drivers/media/usb/cx231xx/cx231xx-video.c
@@ -1389,7 +1389,7 @@ int cx231xx_g_register(struct file *file, void *priv,
ret = cx231xx_read_ctrl_reg(dev, VRT_GET_REGISTER,
(u16)reg->reg, value, 4);
reg->val = value[0] | value[1] << 8 |
- value[2] << 16 | value[3] << 24;
+ value[2] << 16 | (u32)value[3] << 24;
reg->size = 4;
break;
case 1: /* AFE - read byte */
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2018-10-06 18:01 [PATCH] media: cx231xx: fix potential sign-extension overflow on large shift Colin King
2018-10-06 18:01 ` Colin King
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