From: Vadim Pasternak vadimp@nvidia.com
stable inclusion from stable-5.10.75 commit c216cebdd245b6d8546950269453d89414eda973 bugzilla: 182987 https://gitee.com/openeuler/kernel/issues/I4I3MP
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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 vadimp@nvidia.com Link: https://lore.kernel.org/r/20210927142214.2613929-2-vadimp@nvidia.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- 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 7646708d57e4..a023ec02126b 100644 --- a/drivers/platform/mellanox/mlxreg-io.c +++ b/drivers/platform/mellanox/mlxreg-io.c @@ -141,7 +141,7 @@ 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;