This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-focal -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-oem-5.6 in Ubuntu. https://bugs.launchpad.net/bugs/1919277 Title: l2tp.sh from net in ubuntu_kernel_selftests cause dmesg flooded with "unregister_netdevice: waiting for eth0 to become free. Usage count = 1" on F-OEM-5.6 Status in ubuntu-kernel-tests: In Progress Status in linux-oem-5.6 package in Ubuntu: Invalid Status in linux-oem-5.6 source package in Focal: Fix Committed Bug description: [Impact] While debugging bug 1880631, I found that this l2tp.sh test from kselftest/net will cause the dmesg output on Focal OEM 5.6 kernel flooded with: "unregister_netdevice: waiting for eth0 to become free. Usage count = 1" for about every 10 seconds. Test log: $ sudo ./l2tp.sh TEST: IPv4 basic L2TP tunnel [ OK ] TEST: IPv4 route through L2TP tunnel [ OK ] TEST: IPv6 basic L2TP tunnel [ OK ] TEST: IPv6 route through L2TP tunnel [ OK ] TEST: IPv4 basic L2TP tunnel - with IPsec [ OK ] TEST: IPv4 route through L2TP tunnel - with IPsec [ OK ] TEST: IPv6 basic L2TP tunnel - with IPsec [ OK ] TEST: IPv6 route through L2TP tunnel - with IPsec [ OK ] TEST: IPv4 basic L2TP tunnel [ OK ] TEST: IPv4 route through L2TP tunnel [ OK ] TEST: IPv6 basic L2TP tunnel - with IPsec [ OK ] TEST: IPv6 route through L2TP tunnel - with IPsec [ OK ] TEST: IPv4 basic L2TP tunnel - after IPsec teardown [ OK ] TEST: IPv4 route through L2TP tunnel - after IPsec teardown [ OK ] TEST: IPv6 basic L2TP tunnel - after IPsec teardown [ OK ] TEST: IPv6 route through L2TP tunnel - after IPsec teardown [ OK ] Tests passed: 16 Tests failed: 0 dmesg output: $ dmesg [ 708.560589] eth1: renamed from tmp [ 708.587396] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready [ 708.587472] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 708.616950] eth2: renamed from tmp [ 708.643341] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 708.687057] l2tp_core: L2TP core driver, V2.0 [ 708.689380] l2tp_netlink: L2TP netlink interface [ 708.695479] l2tp_ip: L2TP IP encapsulation support (L2TPv3) [ 708.700061] l2tp_eth: L2TP ethernet pseudowire support (L2TPv3) [ 708.726295] l2tp_ip6: L2TP IP encapsulation support for IPv6 (L2TPv3) [ 708.788973] Initializing XFRM netlink socket [ 719.448364] unregister_netdevice: waiting for eth0 to become free. Usage count = 1 [ 729.528359] unregister_netdevice: waiting for eth0 to become free. Usage count = 1 [ 739.608359] unregister_netdevice: waiting for eth0 to become free. Usage count = 1 [Fix] * 27d53323664c54 ("l2tp: remove skb_dst_set() from l2tp_xmit_skb()") We have this patch in all of our generic kernels and OEM-5.10, thus for now I can see just OEM-5.6 is affected. For which this patch can be cherry-picked. [Test Case] This can tested with the l2tp.sh script in the kernel tree: # sh ./tools/testing/selftests/net/l2tp.sh With the patched kernel, it won't get flooded with that unregister_netdevice message anymore. Also, I have it tested with ubuntu_stress_smoke_tests as well, to ensure the sctp stressor won't trigger any issue like in bug 1854968. A test kernel can be found here: https://people.canonical.com/~phlin/kernel/lp-1919277-l2tp/ [Where problems could occur] This change is testable. A quick search didn't show any know issue regarding this patch. And with the same fix running in different generic kernel for a while I think the regression potential can be considered as low. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.6.0-1048-oem 5.6.0-1048.52 ProcVersionSignature: User Name 5.6.0-1048.52-oem 5.6.19 Uname: Linux 5.6.0-1048-oem x86_64 ApportVersion: 2.20.11-0ubuntu27.16 Architecture: amd64 CasperMD5CheckResult: skip Date: Tue Mar 16 05:20:45 2021 SourcePackage: linux-signed-oem-5.6 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1919277/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
