I updated the minimum version to Windows 11 22H2 so we can be sure all versions we impact have the bug already fixed: https://chromium-review.googlesource.com/c/chromium/src/+/6656010
We can reconsider down the line if we want, but by the time we do maybe enough users will be updated there or later that it's not worth it. ~ Ari Chivukula (Their/There/They're) On Fri, Jun 20, 2025, 16:00 Rick Byers <rby...@chromium.org> wrote: > LGTM3. Compat risk seems minimal (and yes likely below the bar needed for > API owner approval, but more transparency doesn't hurt). > > On Fri, Jun 20, 2025 at 12:25 AM 'Erik Anderson' via blink-dev < > blink-dev@chromium.org> wrote: > >> There was no new API here and thus no API detection mechanism. It’s just >> a bug fix that ensures sockets are not rapidly reused toward the beginning >> of the available range. >> >> >> >> Even when the bug is present, most networks work fine; it’s stateful >> off-device middleboxes that might not see that the connection got >> terminated and then get confused by a new connection from the same source >> port. The use of this port randomization flag was shipped before, even with >> the Windows bug; it took a couple of major Chrome releases before it was >> determined it should be turned back off. That was the right decision, but >> that’s also an indication that the risk of extreme breakage is low. >> >> >> >> The bug fix shipped has shipped with the Windows monthly security update >> at least as early as November 2023 (some releases earlier). At this point, >> only a device that hasn’t taken a security update from Windows for 18+ >> months would see the buggy behavior. I suppose if you wanted to be >> extremely paranoid, you could look at the fourth version component on those >> older versions to check for that update. Or just scoping to 22H2+ is >> reasonable too. >> >> >> >> *From:* Ari Chivukula <aric...@chromium.org> >> *Sent:* Thursday, June 19, 2025 6:50 PM >> *To:* Will Harris <w...@chromium.org>; Erik Anderson < >> erik.ander...@microsoft.com> >> *Cc:* Jeremy Roman <jbro...@chromium.org>; Domenic Denicola < >> dome...@chromium.org>; blink-dev <blink-dev@chromium.org>; Andrew >> Williams <awil...@chromium.org>; Mike Taylor <miketa...@chromium.org> >> *Subject:* [EXTERNAL] Re: [blink-dev] Re: Intent to Ship: Randomizing >> TCP Port Allocation on Windows >> >> >> >> Not to my knowledge, but I'm adding @erik.ander...@microsoft.com >> <erik.ander...@microsoft.com> in case there is something I missed. >> >> >> >> I'm fine with starting with 22H2+ only for now, and adding 20H1+ only if >> there's a reliable way to detect the fix or metrics on fix rollout % that >> are convincing. >> >> >> >> ~ Ari Chivukula (Their/There/They're) >> >> >> >> On Thu, Jun 19, 2025, 14:21 Will Harris <w...@chromium.org> wrote: >> >> in general, it's preferable to do a capability test via an OS API rather >> than simply gate on Windows version. Does the new API that Microsoft added >> (and backported) provide a way for the OS to signal that this >> better/working API is available? >> >> >> >> Will >> >> >> >> On Thu, Jun 19, 2025 at 11:15 AM Ari Chivukula <aric...@chromium.org> >> wrote: >> >> That's probably possible, though hopefully they have installed system >> updates in the past year. We could just target 2022H2 and later if needed. >> >> >> >> ~ Ari Chivukula (Their/There/They're) >> >> >> >> >> >> On Thu, Jun 19, 2025 at 10:54 AM Jeremy Roman <jbro...@chromium.org> >> wrote: >> >> >> >> >> >> On Thu, Jun 19, 2025 at 12:10 AM Domenic Denicola <dome...@chromium.org> >> wrote: >> >> I believe this should be completely unobservable to web authors, right? >> (Apart from maybe fewer or more network errors.) >> >> >> >> If so, I don't think this needs any LGTMs, as it fits well under the >> Web-developer-facing >> change to existing behavior >> <https://www.chromium.org/blink/launching-features/#behavior-changes> >> category. >> (Which is... confusingly named >> <https://github.com/GoogleChrome/chromium-dashboard/issues/5145>.) But, >> in case it helps, LGTM1. >> >> On Thursday, June 19, 2025 at 12:12:34 AM UTC+9 Ari Chivukula wrote: >> >> *Contact emails* >> >> aric...@chromium.org, awil...@chromium.org, miketa...@chromium.org >> Explainer >> >> None >> Specification >> >> None >> >> >> >> *Summary* >> >> This launch enables TCP port randomization on versions of Windows (2020 >> H1 or later) where we do not expect to see issues with re-use of prior >> ports occurring too fast (causing rejection due to timeouts on port >> re-use). The rapid port re-use issue arises from the Birthday problem >> <https://en.wikipedia.org/wiki/Birthday_problem>, where the probability >> of randomly re-picking a port already seen rapidly converges with 100% for >> each new port chosen when compared to port re-use in a sequential model. >> >> >> >> *Blink component* >> >> Blink>Network >> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ENetwork%22> >> >> >> >> *TAG review* >> >> None >> >> >> >> *TAG review status* >> >> Not applicable >> >> >> >> *Motivation* >> >> When port randomization is disabled (the default), sites are able to >> count the amount of connections opened by other tabs if they check the TCP >> port used for new connections before and after opening another window. This >> knowledge can be used to glean information about other sites like whether >> they are logged in or not. >> >> >> >> *Risks* >> >> >> >> *Interoperability and Compatibility* >> >> This launch only impacts Windows, and should not cause compatibility >> issues as Microsoft backported their port randomization fix >> <https://chromium-review.googlesource.com/c/chromium/src/+/5464674> to >> Windows 10, 2020 H1 and tested it in Edge. >> >> >> >> Is it possible that we have users on versions >= 2020H1, < 2022H2 but who >> have not received the backported fix (e.g., because they have not installed >> the applicable update)? Would they encounter brokenness in Chrome? >> >> >> >> >> >> Chrome previously attempted to roll this out in 2021 but ran into (since >> resolved) issues where rapid port re-use caused network errors. >> >> >> >> Rollout on linux isn’t needed as port randomization is enabled by default >> while on macOS an issue similar to the one on Windows with rapid port >> re-use causing issues is still around. >> >> >> >> *Gecko:* Appears to inherit OS defaults >> <https://github.com/search?q=repo%3Amozilla-firefox%2Ffirefox+setsockopt&type=code&p=1> >> >> >> >> *WebKit:* Appears to inherit OS defaults >> <https://github.com/search?q=repo%3AWebKit%2FWebKit+setsockopt&type=code> >> >> >> >> *Web developers:* N/A >> >> >> >> *Debuggability* >> >> This will be gated behind the base::feature kTcpPortRandomizationWin, so >> if breakage is suspected that flag could be turned off to detect impact. >> For how to control feature flags, see this >> <https://source.chromium.org/chromium/chromium/src/+/main:base/feature_list.h;drc=159a65729cf8fca4d9f453d12d97ab6515360491;l=259> >> . >> >> >> >> *Measurement* >> >> The histogram Net.TCPSocket.PortReuseTimeWindows2.{IPType}.{Result} will >> be used to gauge whether port re-use timings fall too low, while >> Net.TcpConnectAttempt.Latency.{Result} will be used to detect increases in >> overall connection failure rates. >> >> >> >> *Will this feature be supported on all six Blink platforms (Windows, Mac, >> Linux, ChromeOS, Android, and Android WebView)?* >> >> No, just Windows >> >> >> >> *Is this feature fully tested by web-platform-tests?* >> >> No, as this is a blink networking focused change browser tests or unit >> tests are more likely. >> >> >> >> *Flag name on about://flags* >> >> None >> >> >> >> *Finch feature name* >> >> kTcpPortRandomizationWin >> >> >> >> *Rollout plan* >> >> This will be rolled out slowly to detect issues early and either change >> the version target or roll back. We don’t believe an experiment is needed >> or desired as the issues we saw before were not very prevalent, we likely >> need to go beyond 1% to get enough data on Windows to know if there’s still >> a problem. >> >> >> >> *Requires code in //chrome?* >> >> No >> >> >> >> *Tracking bug* >> >> https://crbug.com/40744069 >> >> >> >> *Estimated milestones* >> >> 139 >> >> >> >> *Link to entry on the Chrome Platform Status* >> >> https://chromestatus.com/feature/5106900286570496 >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to blink-dev+unsubscr...@chromium.org. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/5ac125fa-3adf-4193-a1ff-1bf28f2f6020n%40chromium.org >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/5ac125fa-3adf-4193-a1ff-1bf28f2f6020n%40chromium.org?utm_medium=email&utm_source=footer> >> . >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to blink-dev+unsubscr...@chromium.org. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DJXMP6tCc8KFK_sC07jAbxuX7e%3Dz2sBS-L%2BPU790vafdg%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DJXMP6tCc8KFK_sC07jAbxuX7e%3Dz2sBS-L%2BPU790vafdg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to blink-dev+unsubscr...@chromium.org. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DL_yey6QTmOv2mSx-uSyvTHebqDt3s3sm_KMxRZwKSqaA%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DL_yey6QTmOv2mSx-uSyvTHebqDt3s3sm_KMxRZwKSqaA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to blink-dev+unsubscr...@chromium.org. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CH3PR00MB2435EDBEB1E8700F82B37597F47CA%40CH3PR00MB2435.namprd00.prod.outlook.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CH3PR00MB2435EDBEB1E8700F82B37597F47CA%40CH3PR00MB2435.namprd00.prod.outlook.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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