[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-27 Thread Launchpad Bug Tracker
This bug was fixed in the package isc-dhcp - 4.4.1-2.1ubuntu5.20.04.5 --- isc-dhcp (4.4.1-2.1ubuntu5.20.04.5) focal; urgency=medium [ Mauricio Faria de Oliveira ] * Prevent race condition that might ignore DHCP OFFERs/ACKs when dhclient receives DHCP traffic noise. (LP: #19261

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-27 Thread Launchpad Bug Tracker
This bug was fixed in the package isc-dhcp - 4.4.1-2.3ubuntu2.4 --- isc-dhcp (4.4.1-2.3ubuntu2.4) jammy; urgency=medium [ Mauricio Faria de Oliveira ] * Prevent race condition that might ignore DHCP OFFERs/ACKs when dhclient receives DHCP traffic noise. (LP: #1926139) The

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-15 Thread Mauricio Faria de Oliveira
The -proposed packages have also been verified by the Microsoft Azure team. 14k+ VM deployments with the fix didn't observe the issue over the weekend. Marking jammy/focal as verified based on that plus 2 synthetic tests above. ** Tags removed: verification-needed verification-needed-focal verif

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-15 Thread Mauricio Faria de Oliveira
verification done on focal (full steps in comment #9) The issue is not reproducible with the package in -proposed, and is reproducible with the 2 switches for the old behavior (DHCP_FD_FLAGS_POKE=0 or dhcp.fd_flags_poke=0), as expected. ... # add-apt-repository -y 'deb http://archive.ubuntu.com/

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-15 Thread Mauricio Faria de Oliveira
verification done on jammy (full steps in comment #9) The issue is not reproducible with the package in -proposed, and is reproducible with the 2 switches for the old behavior (DHCP_FD_FLAGS_POKE=0 or dhcp.fd_flags_poke=0), as expected. ... # add-apt-repository -yp proposed # apt policy isc-dh

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-09 Thread Łukasz Zemczak
Hello Martijn, or anyone else affected, Accepted isc-dhcp into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/isc- dhcp/4.4.1-2.1ubuntu5.20.04.5 in a few hours, and then in the -proposed repository. Please help us by testing this new package.

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-09 Thread Łukasz Zemczak
Hello Martijn, or anyone else affected, Accepted isc-dhcp into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/isc- dhcp/4.4.1-2.3ubuntu2.4 in a few hours, and then in the -proposed repository. Please help us by testing this new package. See ht

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-02-02 Thread Mauricio Faria de Oliveira
** Tags added: se-sru-sponsor-mfo -- You received this bug notification because you are a member of SE SRU ("STS") Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1926139 Title: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-31 Thread Mauricio Faria de Oliveira
>From the 'Where problems could occur' section. Considerations on regressions and approaches. [Where problems could occur] isc-dhcp is a core package, and any change comes with the risk that users would not be able to receive dhcp leases with dhclient, leaving their systems with no IP address and

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-31 Thread Mauricio Faria de Oliveira
From the 'Other Info' section. Detailed analysis of the issue and more. [Other Info] Full log: https://paste.ubuntu.com/p/8yBfw2KR5h/ Log of a working run: https://paste.ubuntu.com/p/N3ZgqrxyQD/ When you tcpdump dhclient, we see all DHCPDISCOVER packets being replied to with DHCPOFFER packets, b

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-31 Thread Mauricio Faria de Oliveira
Pressing Page Down 17 times to go over the bug description sounds like a new record! ;-) Just in case future reviewers don't find that as exciting while going through reviews, I'll move some text into comments and reference them from the description. ** Bug watch added: gitlab.isc.org/isc-project

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-27 Thread Mauricio Faria de Oliveira
Jammy/22.04: - test packages in ppa:mfo/lp1926139 - reproduction steps delta (based on comment #9) ... Reproducer based on GDB and DHCP noise injection. It uses 3 veth pairs (DHCP server/client/injector, the latter two under namespaces) on a linux bridge. ... LXD VM: lxc launch ubuntu:jammy

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-26 Thread Mauricio Faria de Oliveira
Test packages: https://launchpad.net/~mfo/+archive/ubuntu/lp1926139 isc-dhcp 4.4.1-2.1ubuntu5.20.04.4+lp1926139.2 Default behavior: issue fixed. --- (gdb) break omapip/dispatch.c:333 (gdb) commands shell sleep 0.2 continue end (gdb) run -d -v vet

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-26 Thread Mauricio Faria de Oliveira
** Patch added: "lp1926139_focal_isc-dhcp_v2.debdiff" https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1926139/+attachment/5643626/+files/lp1926139_focal_isc-dhcp_v2.debdiff -- You received this bug notification because you are a member of SE SRU ("STS") Sponsors, which is subscribed t

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-26 Thread Mauricio Faria de Oliveira
Hey Matthew, Chris, Apparently there's a simpler, less intrusive, and more specific way to do this. Apologies that I missed this earlier, but I found more about the possibilities in bind9-libs functions while checking the previous fix approach for regressions. Could you please provide your thoug

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-24 Thread Matthew Ruffell
** Description changed: [Impact] Occasionally, during instance boot or machine start-up, dhclient will attempt to acquire a dhcp lease and fail, leaving the instance with no IP address and making it unreachable. This happens about once every 100 reboots on bare metal, or Chris Pa

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-22 Thread Chris Patterson
Great work Maurico, I think you make several excellent points and I appreciate your efforts on a better reproducer and alternative patch. FWIW I began testing the Matthew's initial build (which disabled threads) against a large number of VMs and that appeared to address the issues we're seeing. I'

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-18 Thread Mauricio Faria de Oliveira
Reproducer based on GDB and DHCP noise injection. It uses 3 veth pairs (DHCP server/client/injector, the latter two under namespaces) on a linux bridge. LXD VM: $ lxc launch ubuntu:focal lp1926139-focal --vm $ lxc shell lp1926139-focal Network Setup: # ip link add br0 t

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-18 Thread Mauricio Faria de Oliveira
** Patch added: "lp1926139_focal_isc-dhcp.debdiff" https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1926139/+attachment/5642442/+files/lp1926139_focal_isc-dhcp.debdiff -- You received this bug notification because you are a member of SE SRU ("STS") Sponsors, which is subscribed to the

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-18 Thread Mauricio Faria de Oliveira
Hi Matthew, Thanks for the excellent analysis and considerate fix proposal, as always! I looked at this for the last couple of days, for potential sponsorship. I have attentively gone through the SRU template and Other Info section, and considered the proposal to switch bind9-libs into --disable

[Sts-sponsors] [Bug 1926139] Re: dhclient: thread concurrency race leads to DHCPOFFER packets not being received

2023-01-17 Thread Mauricio Faria de Oliveira
** Tags removed: sts-sponsor -- You received this bug notification because you are a member of SE SRU ("STS") Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1926139 Title: dhclient: thread concurrency race leads to DHCPOFFER packets not being received Statu