![]() PPP devices may get automatically unregistered when their network namespace is getting removed. This happens if the ppp control plane daemon (e.g. pppd) exits while it is the last user of this namespace. This leads to several races: * ppp_exit_net() may destroy the per namespace idr (pn->units_idr) before all file descriptors were released. Successive ppp_release() calls may then cleanup PPP devices with ppp_shutdown_interface() and try to use the already destroyed idr. * Automatic device unregistration may also happen before the ppp_release() call for that device gets executed. Once called on the file owning the device, ppp_release() will then clean it up and try to unregister it a second time. To fix these issues, operations defined in ppp_shutdown_interface() are moved to the PPP device's ndo_uninit() callback. This allows PPP devices to be properly cleaned up by unregister_netdev() and friends. So checking for ppp->owner is now an accurate test to decide if a PPP device should be unregistered. Setting ppp->owner is done in ppp_create_interface(), before device registration, in order to avoid unprotected modification of this field. Finally, ppp_exit_net() now starts by unregistering all remaining PPP devices to ensure that none will get unregistered after the call to idr_destroy(). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> |
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.. | ||
bsd_comp.c | ||
Kconfig | ||
Makefile | ||
ppp_async.c | ||
ppp_deflate.c | ||
ppp_generic.c | ||
ppp_mppe.c | ||
ppp_mppe.h | ||
ppp_synctty.c | ||
pppoe.c | ||
pppox.c | ||
pptp.c |