hwmon: (nct6775) Fix loop limit
authorGuenter Roeck <linux@roeck-us.net>
Tue, 12 Jun 2018 22:19:35 +0000 (15:19 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 24 Aug 2018 11:08:56 +0000 (13:08 +0200)
commit4dff89e722d5186e9531a534f1000fee41798176
treec69f8879f0c74e2b67e1cf43f1cf8b3062c237c6
parentc0f29f9d8aa86eec14cf12521597ad5af54e1cc7
hwmon: (nct6775) Fix loop limit

[ 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