This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1796748 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1796748 Title: regression in 'ip --family bridge neigh' since linux v4.12 Status in linux package in Ubuntu: Incomplete Bug description: [Impact] * Netlink RTM_GETNEIGH requests for PF_BRIDGE are broken since linux v4.12. * Users, tools (e.g., iproute2), and libraries (e.g., go netlink) that use such request/family currently receive nothing back in the kernel response. * The upstream fix resolves the breakage in the userspace-kernel interface by explicitly checking for the old/broken request to ensure it's replied. [Test Case] * The command 'ip --family bridge neigh' returns nothing on broken kernels, and matches 'bridge fdb show' on fixed kernels. * Before: $ ip --family bridge neigh $ * After: $ ip --family bridge neigh dev ens3 lladdr 33:33:00:00:00:01 PERMANENT dev ens3 lladdr 01:00:5e:00:00:01 PERMANENT dev ens3 lladdr 33:33:ff:e9:9d:60 PERMANENT * Reference: $ bridge fdb show 33:33:00:00:00:01 dev ens3 self permanent 01:00:5e:00:00:01 dev ens3 self permanent 33:33:ff:e9:9d:60 dev ens3 self permanent [Regression Potential] * Low, for three reasons: * The fix is fairly contained (RTM_GETNEIGH request for PF_BRIDGE family). * The checks introduced by the fix are conservative, based on the size of the old request (the size of the old/new requests are different), and it does nothing different in case the (old) size doesn't match. * Given the above, only applications with message length and contents specially hand-crafted (and likely not valid nor useful) might fail. To the best of my knowledge, this is not the common case out there. [Other Info] * The patch is only applicable to v4.12+ (so not Trusty nor Xenial). * The patch is the same for Bionic, Cosmic, and unstable. * Upstream commit: bd961c9bc664 ("rtnetlink: fix rtnl_fdb_dump() for ndmsg header") https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bd961c9bc66497f0c63f4ba1d02900bb85078366 * I'll submit the patch shortly to the kernel-team mailing list. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1796748/+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