Commit bde74ad1 authored by Moshe Shemesh's avatar Moshe Shemesh Committed by David S. Miller
Browse files

devlink: Add helper function for safely copy string param 



Devlink string param buffer is allocated at the size of
DEVLINK_PARAM_MAX_STRING_VALUE. Add helper function which makes sure
this size is not exceeded.
Renamed DEVLINK_PARAM_MAX_STRING_VALUE to
__DEVLINK_PARAM_MAX_STRING_VALUE to emphasize that it should be used by
devlink only. The driver should use the helper function instead to
verify it doesn't exceed the allowed length.

Signed-off-by: default avatarMoshe Shemesh <moshe@mellanox.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1276534c

include/net/devlink.h

+10 −2
Original line number Diff line number Diff line
@@ -298,7 +298,7 @@ struct devlink_resource { 


#define DEVLINK_RESOURCE_ID_PARENT_TOP 0



#define DEVLINK_PARAM_MAX_STRING_VALUE 32

#define __DEVLINK_PARAM_MAX_STRING_VALUE 32

enum devlink_param_type {

	DEVLINK_PARAM_TYPE_U8,

	DEVLINK_PARAM_TYPE_U16,
@@ -311,7 +311,7 @@ union devlink_param_value { 
	u8 vu8;

	u16 vu16;

	u32 vu32;

	char vstr[DEVLINK_PARAM_MAX_STRING_VALUE];

	char vstr[__DEVLINK_PARAM_MAX_STRING_VALUE];

	bool vbool;

};
@@ -553,6 +553,8 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id, 
int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,

				       union devlink_param_value init_val);

void devlink_param_value_changed(struct devlink *devlink, u32 param_id);

void devlink_param_value_str_fill(union devlink_param_value *dst_val,

				  const char *src);

struct devlink_region *devlink_region_create(struct devlink *devlink,

					     const char *region_name,

					     u32 region_max_snapshots,
@@ -789,6 +791,12 @@ devlink_param_value_changed(struct devlink *devlink, u32 param_id) 
{

}



static inline void

devlink_param_value_str_fill(union devlink_param_value *dst_val,

			     const char *src)

{

}



static inline struct devlink_region *

devlink_region_create(struct devlink *devlink,

		      const char *region_name,

net/core/devlink.c

+18 −1
Original line number Diff line number Diff line
@@ -3015,7 +3015,7 @@ devlink_param_value_get_from_info(const struct devlink_param *param, 
		len = strnlen(nla_data(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]),

			      nla_len(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]));

		if (len == nla_len(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]) ||

		    len >= DEVLINK_PARAM_MAX_STRING_VALUE)

		    len >= __DEVLINK_PARAM_MAX_STRING_VALUE)

			return -EINVAL;

		strcpy(value->vstr,

		       nla_data(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]));
@@ -4617,6 +4617,23 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id) 
}

EXPORT_SYMBOL_GPL(devlink_param_value_changed);



/**

 *	devlink_param_value_str_fill - Safely fill-up the string preventing

 *				       from overflow of the preallocated buffer

 *

 *	@dst_val: destination devlink_param_value

 *	@src: source buffer

 */

void devlink_param_value_str_fill(union devlink_param_value *dst_val,

				  const char *src)

{

	size_t len;



	len = strlcpy(dst_val->vstr, src, __DEVLINK_PARAM_MAX_STRING_VALUE);

	WARN_ON(len >= __DEVLINK_PARAM_MAX_STRING_VALUE);

}

EXPORT_SYMBOL_GPL(devlink_param_value_str_fill);



/**

 *	devlink_region_create - create a new address region

 *

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