3.16.63-rc1 review patch. If anyone has any objections, please let me know.
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From: Colin Ian King colin.king@canonical.com
commit 32ae592036d7aeaabcccb2b1715373a68639a768 upstream.
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 Signed-off-by: Hans Verkuil hverkuil@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/usb/cx231xx/cx231xx-video.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/usb/cx231xx/cx231xx-video.c +++ b/drivers/media/usb/cx231xx/cx231xx-video.c @@ -1271,7 +1271,7 @@ int cx231xx_g_register(struct file *file 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 */