From d10c7e4c08f6ce862142655aac31ff301860f68f Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Wed, 13 Sep 2017 18:02:02 +0100 Subject: [PATCH] staging: iio: ade7759: fix signed extension bug on shift of a u8 commit 13ffe9a26df4e156363579b25c904dd0b1e31bfb upstream. The current shift of st->rx[2] left shifts a u8 24 bits left, promotes the integer to a an int and then to a unsigned u64. If the top bit of st->rx[2] is set then we end up with all the upper bits being set to 1. Fix this by casting st->rx[2] to a u64 before the 24 bit left shift. Detected by CoverityScan CID#144940 ("Unintended sign extension") Fixes: 2919fa54ef64 ("staging: iio: meter: new driver for ADE7759 devices") Signed-off-by: Colin Ian King Signed-off-by: Jonathan Cameron Signed-off-by: Ben Hutchings --- drivers/staging/iio/meter/ade7759.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/iio/meter/ade7759.c b/drivers/staging/iio/meter/ade7759.c index b691f10ce988c..60376d33cd40c 100644 --- a/drivers/staging/iio/meter/ade7759.c +++ b/drivers/staging/iio/meter/ade7759.c @@ -128,7 +128,7 @@ static int ade7759_spi_read_reg_40(struct device *dev, reg_address); goto error_ret; } - *val = ((u64)st->rx[1] << 32) | (st->rx[2] << 24) | + *val = ((u64)st->rx[1] << 32) | ((u64)st->rx[2] << 24) | (st->rx[3] << 16) | (st->rx[4] << 8) | st->rx[5]; error_ret: -- 2.47.2