linux/net/ax25
Lin Ma 1ade48d0c2 ax25: NPD bug when detaching AX25 device
The existing cleanup routine implementation is not well synchronized
with the syscall routine. When a device is detaching, below race could
occur.

static int ax25_sendmsg(...) {
  ...
  lock_sock()
  ax25 = sk_to_ax25(sk);
  if (ax25->ax25_dev == NULL) // CHECK
  ...
  ax25_queue_xmit(skb, ax25->ax25_dev->dev); // USE
  ...
}

static void ax25_kill_by_device(...) {
  ...
  if (s->ax25_dev == ax25_dev) {
    s->ax25_dev = NULL;
    ...
}

Other syscall functions like ax25_getsockopt, ax25_getname,
ax25_info_show also suffer from similar races. To fix them, this patch
introduce lock_sock() into ax25_kill_by_device in order to guarantee
that the nullify action in cleanup routine cannot proceed when another
socket request is pending.

Signed-off-by: Hanjie Wu <nagi@zju.edu.cn>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-18 12:33:56 +00:00
..
af_ax25.c ax25: NPD bug when detaching AX25 device 2021-12-18 12:33:56 +00:00
ax25_addr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_dev.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_ds_in.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_ds_subr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_ds_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_iface.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_in.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_ip.c ax25: use skb_expand_head 2021-08-03 11:21:39 +01:00
ax25_out.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_route.c ax25: use skb_expand_head 2021-08-03 11:21:39 +01:00
ax25_std_in.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_std_subr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_std_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_subr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25_uid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Kconfig AX.25 Kconfig: Replace HTTP links with HTTPS ones 2020-07-13 12:34:06 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysctl_net_ax25.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00