linux/net/x25/sysctl_net_x25.c
Joel Granados 78a7b5dbc0 ax.25: x.25: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Avoid a buffer overflow when traversing the ctl_table by ensuring that
AX25_MAX_VALUES is the same as the size of ax25_param_table. This is
done with a BUILD_BUG_ON where ax25_param_table is defined and a
CONFIG_AX25_DAMA_SLAVE guard in the unnamed enum definition as well as
in the ax25_dev_device_up and ax25_ds_set_timer functions.

The overflow happened when the sentinel was removed from
ax25_param_table. The sentinel's data element was changed when
CONFIG_AX25_DAMA_SLAVE was undefined. This had no adverse effects as it
still stopped on the sentinel's null procname but needed to be addressed
once the sentinel was removed.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-05-03 13:29:43 +01:00

88 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* -*- linux-c -*-
* sysctl_net_x25.c: sysctl interface to net X.25 subsystem.
*
* Begun April 1, 1996, Mike Shaver.
* Added /proc/sys/net/x25 directory entry (empty =) ). [MS]
*/
#include <linux/sysctl.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <net/x25.h>
static int min_timer[] = { 1 * HZ };
static int max_timer[] = { 300 * HZ };
static struct ctl_table_header *x25_table_header;
static struct ctl_table x25_table[] = {
{
.procname = "restart_request_timeout",
.data = &sysctl_x25_restart_request_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &min_timer,
.extra2 = &max_timer,
},
{
.procname = "call_request_timeout",
.data = &sysctl_x25_call_request_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &min_timer,
.extra2 = &max_timer,
},
{
.procname = "reset_request_timeout",
.data = &sysctl_x25_reset_request_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &min_timer,
.extra2 = &max_timer,
},
{
.procname = "clear_request_timeout",
.data = &sysctl_x25_clear_request_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &min_timer,
.extra2 = &max_timer,
},
{
.procname = "acknowledgement_hold_back_timeout",
.data = &sysctl_x25_ack_holdback_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &min_timer,
.extra2 = &max_timer,
},
{
.procname = "x25_forward",
.data = &sysctl_x25_forward,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
};
int __init x25_register_sysctl(void)
{
x25_table_header = register_net_sysctl(&init_net, "net/x25", x25_table);
if (!x25_table_header)
return -ENOMEM;
return 0;
}
void x25_unregister_sysctl(void)
{
unregister_net_sysctl_table(x25_table_header);
}