transport: Reduce pointer usage in Stream structs#8624
Conversation
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## master #8624 +/- ##
==========================================
- Coverage 82.12% 82.06% -0.06%
==========================================
Files 415 415
Lines 40701 40709 +8
==========================================
- Hits 33425 33408 -17
- Misses 5895 5924 +29
+ Partials 1381 1377 -4
🚀 New features to boost your workflow:
|
a44546b to
4ebd663
Compare
4ebd663 to
42b1067
Compare
| func newWriteQuota(sz int32, done <-chan struct{}) *writeQuota { | ||
| w := &writeQuota{ | ||
| func initWriteQuota(wq *writeQuota, sz int32, done <-chan struct{}) { | ||
| *wq = writeQuota{ |
There was a problem hiding this comment.
This syntax does feel a little weird to me. Did you try some of these options to see if they read better (and don't perform worse)?
- directly set fields of
wqin here instead of settingwqto a completely new instance ofwriteQuota - Can this
initWriteQuotabe a method onStream? - Can we make the zero value of
writeQoutasomething that can actually work?
This comment applies to other types as well like recvBuffer.
Thanks.
There was a problem hiding this comment.
I refactored the function into a method with a pointer receiver and replaced the single struct literal assignment with individual field assignments. I also added a godoc comment to explain that this initialization pattern is used to avoid heap allocations. Individual field assignment may be slightly faster than the struct assignment as it avoid allocating an intermediate object on the stack before copying it over.
I defined the method on the writeQuota struct itself, rather than on the Stream struct. This keeps the initialization logic co-located with its type and reduces coupling with Stream.
easwars
left a comment
There was a problem hiding this comment.
How do we ensure that we don't have pointer fields inside structs (as much as possible/feasible/required) going forward? At least personally, if I have a field in a struct that has a pointer receiver, I by default store that field as a pointer. And if I see someone else doing the same in a code review, I would not even notice it, because it is so ingrained in me.
Some of the things mentioned in the docs you said were very useful. But I'm wondering how we make that knowledge more accessible to everyone on the team and ensure we keep certain things in mind when writing and reviewing code.
There was a problem hiding this comment.
Should we move this to the top as well as the link you sent initially also said grouping pointer fields at the top of the struct helps.
dfawley
left a comment
There was a problem hiding this comment.
I don't think there's any way to make this foolproof. We must allow pointers in structs, for obvious reasons. We could possibly add a test that runs a quick local benchmark for a fixed number of iterations, and checks the number & size of allocations afterwards?
|
Filed an issue to add a performance regression test: #8633 |
…jo) (#12794) This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [google.golang.org/grpc](https://github.com/grpc/grpc-go) | `v1.75.0` → `v1.79.3` |  |  | --- ### gRPC-Go has an authorization bypass via missing leading slash in :path [CVE-2026-33186](https://nvd.nist.gov/vuln/detail/CVE-2026-33186) / [GHSA-p77j-4mvh-x3m3](GHSA-p77j-4mvh-x3m3) / [GO-2026-4762](https://pkg.go.dev/vuln/GO-2026-4762) <details> <summary>More information</summary> #### Details ##### Impact _What kind of vulnerability is it? Who is impacted?_ It is an **Authorization Bypass** resulting from **Improper Input Validation** of the HTTP/2 `:path` pseudo-header. The gRPC-Go server was too lenient in its routing logic, accepting requests where the `:path` omitted the mandatory leading slash (e.g., `Service/Method` instead of `/Service/Method`). While the server successfully routed these requests to the correct handler, authorization interceptors (including the official `grpc/authz` package) evaluated the raw, non-canonical path string. Consequently, "deny" rules defined using canonical paths (starting with `/`) failed to match the incoming request, allowing it to bypass the policy if a fallback "allow" rule was present. **Who is impacted?** This affects gRPC-Go servers that meet both of the following criteria: 1. They use path-based authorization interceptors, such as the official RBAC implementation in `google.golang.org/grpc/authz` or custom interceptors relying on `info.FullMethod` or `grpc.Method(ctx)`. 2. Their security policy contains specific "deny" rules for canonical paths but allows other requests by default (a fallback "allow" rule). The vulnerability is exploitable by an attacker who can send raw HTTP/2 frames with malformed `:path` headers directly to the gRPC server. ##### Patches _Has the problem been patched? What versions should users upgrade to?_ Yes, the issue has been patched. The fix ensures that any request with a `:path` that does not start with a leading slash is immediately rejected with a `codes.Unimplemented` error, preventing it from reaching authorization interceptors or handlers with a non-canonical path string. Users should upgrade to the following versions (or newer): * **v1.79.3** * The latest **master** branch. It is recommended that all users employing path-based authorization (especially `grpc/authz`) upgrade as soon as the patch is available in a tagged release. ##### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ While upgrading is the most secure and recommended path, users can mitigate the vulnerability using one of the following methods: ##### 1. Use a Validating Interceptor (Recommended Mitigation) Add an "outermost" interceptor to your server that validates the path before any other authorization logic runs: ```go func pathValidationInterceptor(ctx context.Context, req any, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (any, error) { if info.FullMethod == "" || info.FullMethod[0] != '/' { return nil, status.Errorf(codes.Unimplemented, "malformed method name") } return handler(ctx, req) } // Ensure this is the FIRST interceptor in your chain s := grpc.NewServer( grpc.ChainUnaryInterceptor(pathValidationInterceptor, authzInterceptor), ) ``` ##### 2. Infrastructure-Level Normalization If your gRPC server is behind a reverse proxy or load balancer (such as Envoy, NGINX, or an L7 Cloud Load Balancer), ensure it is configured to enforce strict HTTP/2 compliance for pseudo-headers and reject or normalize requests where the `:path` header does not start with a leading slash. ##### 3. Policy Hardening Switch to a "default deny" posture in your authorization policies (explicitly listing all allowed paths and denying everything else) to reduce the risk of bypasses via malformed inputs. #### Severity - CVSS Score: 9.1 / 10 (Critical) - Vector String: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N` #### References - [https://github.com/grpc/grpc-go/security/advisories/GHSA-p77j-4mvh-x3m3](https://github.com/grpc/grpc-go/security/advisories/GHSA-p77j-4mvh-x3m3) - [https://nvd.nist.gov/vuln/detail/CVE-2026-33186](https://nvd.nist.gov/vuln/detail/CVE-2026-33186) - [https://github.com/grpc/grpc-go](https://github.com/grpc/grpc-go) This data is provided by [OSV](https://osv.dev/vulnerability/GHSA-p77j-4mvh-x3m3) and the [GitHub Advisory Database](https://github.com/github/advisory-database) ([CC-BY 4.0](https://github.com/github/advisory-database/blob/main/LICENSE.md)). </details> --- ### Authorization bypass in gRPC-Go via missing leading slash in :path in google.golang.org/grpc [CVE-2026-33186](https://nvd.nist.gov/vuln/detail/CVE-2026-33186) / [GHSA-p77j-4mvh-x3m3](GHSA-p77j-4mvh-x3m3) / [GO-2026-4762](https://pkg.go.dev/vuln/GO-2026-4762) <details> <summary>More information</summary> #### Details Authorization bypass in gRPC-Go via missing leading slash in :path in google.golang.org/grpc #### Severity Unknown #### References - [https://github.com/grpc/grpc-go/security/advisories/GHSA-p77j-4mvh-x3m3](https://github.com/grpc/grpc-go/security/advisories/GHSA-p77j-4mvh-x3m3) This data is provided by [OSV](https://osv.dev/vulnerability/GO-2026-4762) and the [Go Vulnerability Database](https://github.com/golang/vulndb) ([CC-BY 4.0](https://github.com/golang/vulndb#license)). </details> --- ### Release Notes <details> <summary>grpc/grpc-go (google.golang.org/grpc)</summary> ### [`v1.79.3`](https://github.com/grpc/grpc-go/releases/tag/v1.79.3): Release 1.79.3 [Compare Source](grpc/grpc-go@v1.79.2...v1.79.3) ### Security - server: fix an authorization bypass where malformed :path headers (missing the leading slash) could bypass path-based restricted "deny" rules in interceptors like `grpc/authz`. Any request with a non-canonical path is now immediately rejected with an `Unimplemented` error. ([#​8981](grpc/grpc-go#8981)) ### [`v1.79.2`](https://github.com/grpc/grpc-go/releases/tag/v1.79.2): Release 1.79.2 [Compare Source](grpc/grpc-go@v1.79.1...v1.79.2) ### Bug Fixes - stats: Prevent redundant error logging in health/ORCA producers by skipping stats/tracing processing when no stats handler is configured. ([#​8874](grpc/grpc-go#8874)) ### [`v1.79.1`](https://github.com/grpc/grpc-go/releases/tag/v1.79.1): Release 1.79.1 [Compare Source](grpc/grpc-go@v1.79.0...v1.79.1) ### Bug Fixes - grpc: Remove the `-dev` suffix from the User-Agent header. ([#​8902](grpc/grpc-go#8902)) ### [`v1.79.0`](https://github.com/grpc/grpc-go/releases/tag/v1.79.0): Release 1.79.0 [Compare Source](grpc/grpc-go@v1.78.0...v1.79.0) ### API Changes - mem: Add experimental API `SetDefaultBufferPool` to change the default buffer pool. ([#​8806](grpc/grpc-go#8806)) - Special Thanks: [@​vanja-p](https://github.com/vanja-p) - experimental/stats: Update `MetricsRecorder` to require embedding the new `UnimplementedMetricsRecorder` (a no-op struct) in all implementations for forward compatibility. ([#​8780](grpc/grpc-go#8780)) ### Behavior Changes - balancer/weightedtarget: Remove handling of `Addresses` and only handle `Endpoints` in resolver updates. ([#​8841](grpc/grpc-go#8841)) ### New Features - experimental/stats: Add support for asynchronous gauge metrics through the new `AsyncMetricReporter` and `RegisterAsyncReporter` APIs. ([#​8780](grpc/grpc-go#8780)) - pickfirst: Add support for weighted random shuffling of endpoints, as described in [gRFC A113](grpc/proposal#535). - This is enabled by default, and can be turned off using the environment variable `GRPC_EXPERIMENTAL_PF_WEIGHTED_SHUFFLING`. ([#​8864](grpc/grpc-go#8864)) - xds: Implement `:authority` rewriting, as specified in [gRFC A81](https://github.com/grpc/proposal/blob/master/A81-xds-authority-rewriting.md). ([#​8779](grpc/grpc-go#8779)) - balancer/randomsubsetting: Implement the `random_subsetting` LB policy, as specified in [gRFC A68](https://github.com/grpc/proposal/blob/master/A68-random-subsetting.md). ([#​8650](grpc/grpc-go#8650)) - Special Thanks: [@​marek-szews](https://github.com/marek-szews) ### Bug Fixes - credentials/tls: Fix a bug where the port was not stripped from the authority override before validation. ([#​8726](grpc/grpc-go#8726)) - Special Thanks: [@​Atul1710](https://github.com/Atul1710) - xds/priority: Fix a bug causing delayed failover to lower-priority clusters when a higher-priority cluster is stuck in `CONNECTING` state. ([#​8813](grpc/grpc-go#8813)) - health: Fix a bug where health checks failed for clients using legacy compression options (`WithDecompressor` or `RPCDecompressor`). ([#​8765](grpc/grpc-go#8765)) - Special Thanks: [@​sanki92](https://github.com/sanki92) - transport: Fix an issue where the HTTP/2 server could skip header size checks when terminating a stream early. ([#​8769](grpc/grpc-go#8769)) - Special Thanks: [@​joybestourous](https://github.com/joybestourous) - server: Propagate status detail headers, if available, when terminating a stream during request header processing. ([#​8754](grpc/grpc-go#8754)) - Special Thanks: [@​joybestourous](https://github.com/joybestourous) ### Performance Improvements - credentials/alts: Optimize read buffer alignment to reduce copies. ([#​8791](grpc/grpc-go#8791)) - mem: Optimize pooling and creation of `buffer` objects. ([#​8784](grpc/grpc-go#8784)) - transport: Reduce slice re-allocations by reserving slice capacity. ([#​8797](grpc/grpc-go#8797)) ### [`v1.78.0`](https://github.com/grpc/grpc-go/releases/tag/v1.78.0): Release 1.78.0 [Compare Source](grpc/grpc-go@v1.77.0...v1.78.0) ### Behavior Changes - client: Align URL validation with Go 1.26+ to now reject target URLs with unbracketed colons in the hostname. ([#​8716](grpc/grpc-go#8716)) - Special Thanks: [@​neild](https://github.com/neild) - transport/client : Return status code `Unknown` on malformed grpc-status. ([#​8735](grpc/grpc-go#8735)) - - xds/resolver: - Drop previous route resources and report an error when no matching virtual host is found. - Only log LDS/RDS configuration errors following a successful update and retain the last valid resource to prevent transient failures. ([#​8711](grpc/grpc-go#8711)) ### New Features - stats/otel: Add backend service label to weighted round robin metrics as part of A89. ([#​8737](grpc/grpc-go#8737)) - stats/otel: Add subchannel metrics (without the disconnection reason) to eventually replace the pickfirst metrics. ([#​8738](grpc/grpc-go#8738)) - client: Wait for all pending goroutines to complete when closing a graceful switch balancer. ([#​8746](grpc/grpc-go#8746)) - Special Thanks: [@​twz123](https://github.com/twz123) - client: Add `experimental.AcceptCompressors` so callers can restrict the `grpc-accept-encoding` header advertised for a call. ([#​8718](grpc/grpc-go#8718)) - Special Thanks: [@​iblancasa](https://github.com/iblancasa) ### Bug Fixes - xds: Fix a bug in `StringMatcher` where regexes would match incorrectly when ignore\_case is set to true. ([#​8723](grpc/grpc-go#8723)) - client: - Change connectivity state to CONNECTING when creating the name resolver (as part of exiting IDLE). - Change connectivity state to TRANSIENT\_FAILURE if name resolver creation fails (as part of exiting IDLE). - Change connectivity state to IDLE after idle timeout expires even when current state is TRANSIENT\_FAILURE. - Fix a bug that resulted in `OnFinish` call option not being invoked for RPCs where stream creation failed. ([#​8710](grpc/grpc-go#8710)) - xdsclient: Fix a race in the xdsClient that could lead to resource-not-found errors. ([#​8627](grpc/grpc-go#8627)) ### Performance Improvements - mem: Round up to nearest 4KiB for pool allocations larger than 1MiB. ([#​8705](grpc/grpc-go#8705)) - Special Thanks: [@​cjc25](https://github.com/cjc25) ### [`v1.77.0`](https://github.com/grpc/grpc-go/releases/tag/v1.77.0): Release 1.77.0 [Compare Source](grpc/grpc-go@v1.76.0...v1.77.0) ### API Changes - mem: Replace the `Reader` interface with a struct for better performance and maintainability. ([#​8669](grpc/grpc-go#8669)) ### Behavior Changes - balancer/pickfirst: Remove support for the old `pick_first` LB policy via the environment variable `GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST=false`. The new `pick_first` has been the default since `v1.71.0`. ([#​8672](grpc/grpc-go#8672)) ### Bug Fixes - xdsclient: Fix a race condition in the ADS stream implementation that could result in `resource-not-found` errors, causing the gRPC client channel to move to `TransientFailure`. ([#​8605](grpc/grpc-go#8605)) - client: Ignore HTTP status header for gRPC streams. ([#​8548](grpc/grpc-go#8548)) - client: Set a read deadline when closing a transport to prevent it from blocking indefinitely on a broken connection. ([#​8534](grpc/grpc-go#8534)) - Special Thanks: [@​jgold2-stripe](https://github.com/jgold2-stripe) - client: Fix a bug where default port 443 was not automatically added to addresses without a specified port when sent to a proxy. - Setting environment variable `GRPC_EXPERIMENTAL_ENABLE_DEFAULT_PORT_FOR_PROXY_TARGET=false` disables this change; please file a bug if any problems are encountered as we will remove this option soon. ([#​8613](grpc/grpc-go#8613)) - balancer/pickfirst: Fix a bug where duplicate addresses were not being ignored as intended. ([#​8611](grpc/grpc-go#8611)) - server: Fix a bug that caused overcounting of channelz metrics for successful and failed streams. ([#​8573](grpc/grpc-go#8573)) - Special Thanks: [@​hugehoo](https://github.com/hugehoo) - balancer/pickfirst: When configured, shuffle addresses in resolver updates that lack endpoints. Since gRPC automatically adds endpoints to resolver updates, this bug only affects custom LB policies that delegate to `pick_first` but don't set endpoints. ([#​8610](grpc/grpc-go#8610)) - mem: Clear large buffers before re-using. ([#​8670](grpc/grpc-go#8670)) ### Performance Improvements - transport: Reduce heap allocations to reduce time spent in garbage collection. ([#​8624](grpc/grpc-go#8624), [#​8630](grpc/grpc-go#8630), [#​8639](grpc/grpc-go#8639), [#​8668](grpc/grpc-go#8668)) - transport: Avoid copies when reading and writing Data frames. ([#​8657](grpc/grpc-go#8657), [#​8667](grpc/grpc-go#8667)) - mem: Avoid clearing newly allocated buffers. ([#​8670](grpc/grpc-go#8670)) ### New Features - outlierdetection: Add metrics specified in [gRFC A91](https://github.com/grpc/proposal/blob/master/A91-outlier-detection-metrics.md). ([#​8644](grpc/grpc-go#8644)) - Special Thanks: [@​davinci26](https://github.com/davinci26), [@​PardhuKonakanchi](https://github.com/PardhuKonakanchi) - stats/opentelemetry: Add support for optional label `grpc.lb.backend_service` in per-call metrics ([#​8637](grpc/grpc-go#8637)) - xds: Add support for JWT Call Credentials as specified in [gRFC A97](https://github.com/grpc/proposal/blob/master/A97-xds-jwt-call-creds.md). Set environment variable `GRPC_EXPERIMENTAL_XDS_BOOTSTRAP_CALL_CREDS=true` to enable this feature. ([#​8536](grpc/grpc-go#8536)) - Special Thanks: [@​dimpavloff](https://github.com/dimpavloff) - experimental/stats: Add support for up/down counters. ([#​8581](grpc/grpc-go#8581)) ### [`v1.76.0`](https://github.com/grpc/grpc-go/releases/tag/v1.76.0): Release 1.76.0 [Compare Source](grpc/grpc-go@v1.75.1...v1.76.0) ### Dependencies - Minimum supported Go version is now 1.24 ([#​8509](grpc/grpc-go#8509)) - Special Thanks: [@​kevinGC](https://github.com/kevinGC) ### Bug Fixes - client: Return status `INTERNAL` when a server sends zero response messages for a unary or client-streaming RPC. ([#​8523](grpc/grpc-go#8523)) - client: Fail RPCs with status `INTERNAL` instead of `UNKNOWN` upon receiving http headers with status 1xx and `END_STREAM` flag set. ([#​8518](grpc/grpc-go#8518)) - Special Thanks: [@​vinothkumarr227](https://github.com/vinothkumarr227) - pick\_first: Fix race condition that could cause pick\_first to get stuck in `IDLE` state on backend address change. ([#​8615](grpc/grpc-go#8615)) ### New Features - credentials: Add `credentials/jwt` package providing file-based JWT PerRPCCredentials (A97). ([#​8431](grpc/grpc-go#8431)) - Special Thanks: [@​dimpavloff](https://github.com/dimpavloff) ### Performance Improvements - client: Improve HTTP/2 header size estimate to reduce re-allocations. ([#​8547](grpc/grpc-go#8547)) - encoding/proto: Avoid redundant message size calculation when marshaling. ([#​8569](grpc/grpc-go#8569)) - Special Thanks: [@​rs-unity](https://github.com/rs-unity) ### [`v1.75.1`](https://github.com/grpc/grpc-go/releases/tag/v1.75.1): Release 1.75.1 [Compare Source](grpc/grpc-go@v1.75.0...v1.75.1) ### Bug Fixes - transport: Fix a data race while copying headers for stats handlers in the std lib http2 server transport. ([#​8519](grpc/grpc-go#8519)) - xdsclient: - Fix a data race caused while reporting load to LRS. ([#​8483](grpc/grpc-go#8483)) - Fix regression preventing empty node IDs when creating an LRS client. ([#​8483](grpc/grpc-go#8483)) - server: Fix a regression preventing streams from being cancelled or timed out when blocked on flow control. ([#​8528](grpc/grpc-go#8528)) </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - "" - Automerge - Between 12:00 AM and 03:59 AM (`* 0-3 * * *`) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate](https://github.com/renovatebot/renovate). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4xOTUuMSIsInVwZGF0ZWRJblZlciI6IjQzLjE5NS4xIiwidGFyZ2V0QnJhbmNoIjoiZm9yZ2VqbyIsImxhYmVscyI6WyJkZXBlbmRlbmN5LXVwZ3JhZGUiLCJ0ZXN0L25vdC1uZWVkZWQiXX0=--> Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12794 Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>
The pprof profiles for unary RPC benchmarks indicate significant time spent in
runtime.mallocgcandruntime.gcBgMarkWorker. This indicates gRPC is spending significant CPU cycles allocating or garbage collecting.This change reduces the number of pointer fields in the structs that represent client and server stream. This will reduce number of memory allocations (faster) and also reduce pressure on garbage collector (faster garbage collections) since the GC doesn't need to scan non-pointer fields. For structs which were stored as pointers to ensure values are not copied, a
noCopystruct is embedded that will causego vetto fail if copies are performed. Non-pointer fields are also moved to the end of the struct to improve allocation speed.Results
There are improvements in QPS, latency and allocs/op for unary RPCs.
Resources
RELEASE NOTES: