From 9225d57f51e2af57ca317fd2481880221a6b3362 Mon Sep 17 00:00:00 2001 From: Vadim Pasternak Date: Mon, 27 Sep 2021 17:22:13 +0300 Subject: [PATCH] platform/mellanox: mlxreg-io: Fix argument base in kstrtou32() call commit 9b024201693e397441668cca0d2df7055fe572eb upstream. Change kstrtou32() argument 'base' to be zero instead of 'len'. It works by chance for setting one bit value, but it is not supposed to work in case value passed to mlxreg_io_attr_store() is greater than 1. It works for example, for: echo 1 > /sys/devices/platform/mlxplat/mlxreg-io/hwmon/.../jtag_enable But it will fail for: echo n > /sys/devices/platform/mlxplat/mlxreg-io/hwmon/.../jtag_enable, where n > 1. The flow for input buffer conversion is as below: _kstrtoull(const char *s, unsigned int base, unsigned long long *res) calls: rv = _parse_integer(s, base, &_res); For the second case, where n > 1: - _parse_integer() converts 's' to 'val'. For n=2, 'len' is set to 2 (string buffer is 0x32 0x0a), for n=3 'len' is set to 3 (string buffer 0x33 0x0a), etcetera. - 'base' is equal or greater then '2' (length of input buffer). As a result, _parse_integer() exits with result zero (rv): rv = 0; while (1) { ... if (val >= base)-> (2 >= 2) break; ... rv++; ... } And _kstrtoull() in their turn will fail: if (rv == 0) return -EINVAL; Fixes: 5ec4a8ace06c ("platform/mellanox: Introduce support for Mellanox register access driver") Signed-off-by: Vadim Pasternak Link: https://lore.kernel.org/r/20210927142214.2613929-2-vadimp@nvidia.com Signed-off-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman --- drivers/platform/mellanox/mlxreg-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/mellanox/mlxreg-io.c b/drivers/platform/mellanox/mlxreg-io.c index acfaf64ffde6..1c3760c13f83 100644 --- a/drivers/platform/mellanox/mlxreg-io.c +++ b/drivers/platform/mellanox/mlxreg-io.c @@ -123,7 +123,7 @@ mlxreg_io_attr_store(struct device *dev, struct device_attribute *attr, return -EINVAL; /* Convert buffer to input value. */ - ret = kstrtou32(buf, len, &input_val); + ret = kstrtou32(buf, 0, &input_val); if (ret) return ret;