On Tue, Oct 03, 2017 at 09:44:14AM +0200, Beniamino Galvani wrote: > Call Trace: > ppp_destroy_interface+0xd8/0xe0 [ppp_generic] > ppp_disconnect_channel+0xda/0x110 [ppp_generic] > ppp_unregister_channel+0x5e/0x110 [ppp_generic] > pppox_unbind_sock+0x23/0x30 [pppox] > pppoe_connect+0x130/0x440 [pppoe] > SYSC_connect+0x98/0x110 > ? do_fcntl+0x2c0/0x5d0 > SyS_connect+0xe/0x10 > entry_SYSCALL_64_fastpath+0x1a/0xa5 > RIP: 0033:0x7fa71f4af840 > RSP: 002b:00007ffe4ea40bf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a > RAX: ffffffffffffffda RBX: 0000556d37ae0538 RCX: 00007fa71f4af840 > RDX: 000000000000001e RSI: 00007ffe4ea40c00 RDI: 0000000000000008 > RBP: 0000556d37b2a1b0 R08: 0000556d396e95b0 R09: 0000000000000008 > R10: 00000000aaaaaaab R11: 0000000000000246 R12: 0000556d37adc008 > R13: 0000556d37adc004 R14: 0000556d37b2a1a4 R15: 0000000000000000 > Code: 04 00 00 04 e8 cb 52 e3 ff 5b 41 5c 41 5d 5d c3 41 0f b7 84 24 32 02 00 00 4c 89 e7 48 29 c7 e8 80 8b aa ff 5b 41 5c 41 5d 5d c3 <0f> 0b 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 > RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88 > ---[ end trace ed294ff0cc40eeff ]--- > > To reproduce this, establish a PPP connection through pppd, then bring > down and delete the ppp interface: > > # pppd nodetach lock user client plugin rp-pppoe.so ens11 noauth nodeflate password password & > Plugin rp-pppoe.so loaded. > RP-PPPoE plugin version 3.8p compiled against pppd 2.4.7 > PPP session is 16 > Connected to fe:54:00:5f:04:13 via interface ens11 > Using interface ppp0 > Connect: ppp0 <--> ens11 > CHAP authentication succeeded: Access granted > CHAP authentication succeeded > peer from calling number FE:54:00:5F:04:13 authorized > local IP address 3.1.1.10 > remote IP address 3.1.1.1 > > # ip l set ppp0 down > # ip l del ppp0 > > It does not happen every time but only when ppp_destroy_interface() is > called with dev->reg_state = UNREGISTERING, set by the concurrent > rtnl_delete_link(). > Indeed, we have a race here: ppp_destroy_interface() can be called before netdev_run_todo() completes. I'm working on it. -- To unsubscribe from this list: send the line "unsubscribe linux-ppp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
