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
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
ubuntu-kernel-tests |
Fix Released
|
Undecided
|
Po-Hsu Lin | ||
linux-oem-5.6 (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Focal |
Fix Released
|
Undecided
|
Po-Hsu Lin |
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_
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(
[ 708.587472] IPv6: ADDRCONF(
[ 708.616950] eth2: renamed from tmp
[ 708.643341] IPv6: ADDRCONF(
[ 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_
[ 729.528359] unregister_
[ 739.608359] unregister_
[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/
With the patched kernel, it won't get flooded with that
unregister_
Also, I have it tested with ubuntu_
ensure the sctp stressor won't trigger any issue like in bug 1854968.
A test kernel can be found here:
https:/
[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-
ProcVersionSign
Uname: Linux 5.6.0-1048-oem x86_64
ApportVersion: 2.20.11-
Architecture: amd64
CasperMD5CheckR
Date: Tue Mar 16 05:20:45 2021
SourcePackage: linux-signed-
UpgradeStatus: No upgrade log present (probably fresh install)
Changed in ubuntu-kernel-tests: | |
status: | New → In Progress |
Changed in linux-oem-5.6 (Ubuntu Focal): | |
status: | New → In Progress |
assignee: | nobody → Po-Hsu Lin (cypressyew) |
Changed in ubuntu-kernel-tests: | |
assignee: | nobody → Po-Hsu Lin (cypressyew) |
description: | updated |
description: | updated |
description: | updated |
description: | updated |
Changed in linux-oem-5.6 (Ubuntu Focal): | |
status: | In Progress → Fix Committed |
I believe this is the fix https:/ /github. com/torvalds/ linux/commit/ 27d53323664c549 b5bb2dfaaf6f7ad 6e0376a64e