Skip to main content

Browse the archive

https://github.com/torvalds/linux
05 April 2024, 19:05:47 UTC
Revision 7ba1b689038726d34e3244c1ac9e2e18c2ea4787 authored by Ralf Baechle on 09 February 2017, 13:12:11 UTC, committed by David S. Miller on 10 February 2017, 18:41:13 UTC 
NET: mkiss: Fix panic
 
If a USB-to-serial adapter is unplugged, the driver re-initializes, with
dev->hard_header_len and dev->addr_len set to zero, instead of the correct
values.  If then a packet is sent through the half-dead interface, the
kernel will panic due to running out of headroom in the skb when pushing
for the AX.25 headers resulting in this panic:

[<c0595468>] (skb_panic) from [<c0401f70>] (skb_push+0x4c/0x50)
[<c0401f70>] (skb_push) from [<bf0bdad4>] (ax25_hard_header+0x34/0xf4 [ax25])
[<bf0bdad4>] (ax25_hard_header [ax25]) from [<bf0d05d4>] (ax_header+0x38/0x40 [mkiss])
[<bf0d05d4>] (ax_header [mkiss]) from [<c041b584>] (neigh_compat_output+0x8c/0xd8)
[<c041b584>] (neigh_compat_output) from [<c043e7a8>] (ip_finish_output+0x2a0/0x914)
[<c043e7a8>] (ip_finish_output) from [<c043f948>] (ip_output+0xd8/0xf0)
[<c043f948>] (ip_output) from [<c043f04c>] (ip_local_out_sk+0x44/0x48)

This patch makes mkiss behave like the 6pack driver. 6pack does not
panic.  In 6pack.c sp_setup() (same function name here) the values for
dev->hard_header_len and dev->addr_len are set to the same values as in
my mkiss patch.

[ralf@linux-mips.org: Massages original submission to conform to the usual
standards for patch submissions.]

Signed-off-by: Thomas Osterried <thomas@osterried.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent b85ea00
Raw File
Tip revision: 7ba1b689038726d34e3244c1ac9e2e18c2ea4787 authored by Ralf Baechle on 09 February 2017, 13:12:11 UTC
NET: mkiss: Fix panic
Tip revision: 7ba1b68
sysctl.c 
/*
 * linux/fs/nfs/sysctl.c
 *
 * Sysctl interface to NFS parameters
 */
#include <linux/types.h>
#include <linux/linkage.h>
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/sysctl.h>
#include <linux/module.h>
#include <linux/nfs_fs.h>

static struct ctl_table_header *nfs_callback_sysctl_table;

static struct ctl_table nfs_cb_sysctls[] = {
	{
		.procname	= "nfs_mountpoint_timeout",
		.data		= &nfs_mountpoint_expiry_timeout,
		.maxlen		= sizeof(nfs_mountpoint_expiry_timeout),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{
		.procname	= "nfs_congestion_kb",
		.data		= &nfs_congestion_kb,
		.maxlen		= sizeof(nfs_congestion_kb),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{ }
};

static struct ctl_table nfs_cb_sysctl_dir[] = {
	{
		.procname = "nfs",
		.mode = 0555,
		.child = nfs_cb_sysctls,
	},
	{ }
};

static struct ctl_table nfs_cb_sysctl_root[] = {
	{
		.procname = "fs",
		.mode = 0555,
		.child = nfs_cb_sysctl_dir,
	},
	{ }
};

int nfs_register_sysctl(void)
{
	nfs_callback_sysctl_table = register_sysctl_table(nfs_cb_sysctl_root);
	if (nfs_callback_sysctl_table == NULL)
		return -ENOMEM;
	return 0;
}

void nfs_unregister_sysctl(void)
{
	unregister_sysctl_table(nfs_callback_sysctl_table);
	nfs_callback_sysctl_table = NULL;
}
back to top