4.14-stable review patch. If anyone has any objections, please let me know.
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From: Guenter Roeck linux@roeck-us.net
[ Upstream commit 91bb8f45f73f19a0150c233c0f11cdeb6d71d1e9 ]
Commit cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") changed a loop limit from "data->temp_label_num - 1" to "32", as part of moving from a string array to a bit mask. This results in the following error, reported by UBSAN.
UBSAN: Undefined behaviour in drivers/hwmon/nct6775.c:4179:27 shift exponent 32 is too large for 32-bit type 'long unsigned int'
Similar to the original loop, the limit has to be one less than the number of bits.
Fixes: cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") Reported-by: Paul Menzel pmenzel+linux-hwmon@molgen.mpg.de Cc: Paul Menzel pmenzel+linux-hwmon@molgen.mpg.de Tested-by: Paul Menzel pmenzel+linux-hwmon@molgen.mpg.de Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hwmon/nct6775.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -4107,7 +4107,7 @@ static int nct6775_probe(struct platform * The temperature is already monitored if the respective bit in <mask> * is set. */ - for (i = 0; i < 32; i++) { + for (i = 0; i < 31; i++) { if (!(data->temp_mask & BIT(i + 1))) continue; if (!reg_temp_alternate[i])