plumbing: format/packfile, cap delta chain depth in parser#2137
Merged
Conversation
Contributor
There was a problem hiding this comment.
Pull request overview
This PR hardens packfile parsing by adding a Git-compatible delta chain depth limit to prevent malformed packs from driving excessive recursive delta resolution.
Changes:
- Adds
maxDeltaChainDepthand validates parent-chain depth during delta resolution. - Adds a regression test that builds an over-limit OFS delta chain and expects
ErrMalformedPackFile.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
plumbing/format/packfile/parser.go |
Adds the delta depth ceiling and checks objects before resolution. |
plumbing/format/packfile/internal_test.go |
Adds pack-building helpers and an over-depth delta chain regression test. |
Comments suppressed due to low confidence (1)
plumbing/format/packfile/internal_test.go:44
- This regression test only asserts the final error for a valid over-limit chain using a seekable parser with no storage. It would not catch an over-limit child being eagerly resolved before the depth check (for example returning an invalid-delta error first or writing to storage). Add coverage that verifies an over-depth delta is rejected before resolution, such as with a malformed over-limit delta or a storage-backed parser.
_, err = parser.Parse()
require.ErrorIs(t, err, ErrMalformedPackFile)
require.ErrorContains(t, err, "delta chain depth")
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
A pack with a deeply chained delta sequence forced unbounded recursion during parse, letting a malformed input drive arbitrary stack growth. Walk the parent chain before each delta is resolved and reject anything beyond 4095 links — the same ceiling upstream Git enforces via OE_DEPTH_BITS in pack-objects.h — surfacing ErrMalformedPackFile. Adapted from b3850af for v5's resolveDeltas/objectInfo flow. Assisted-by: Claude Opus 4.7 <noreply@anthropic.com> Signed-off-by: Paulo Gomes <paulo@entire.io>
hiddeco
approved these changes
May 18, 2026
chhe
pushed a commit
to chhe/act_runner
that referenced
this pull request
May 19, 2026
This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [github.com/go-git/go-git/v5](https://github.com/go-git/go-git) | `v5.19.0` → `v5.19.1` |  |  | --- ### Release Notes <details> <summary>go-git/go-git (github.com/go-git/go-git/v5)</summary> ### [`v5.19.1`](https://github.com/go-git/go-git/releases/tag/v5.19.1) [Compare Source](go-git/go-git@v5.19.0...v5.19.1) #### What's Changed - v5: plumbing: transport/ssh, Shell-quote path by [@​hiddeco](https://github.com/hiddeco) in [#​2068](go-git/go-git#2068) - v5: git: submodule, Fix relative URL resolution by [@​hiddeco](https://github.com/hiddeco) in [#​2070](go-git/go-git#2070) - v5: git: submodule, canonical remote for relative URLs by [@​hiddeco](https://github.com/hiddeco) in [#​2074](go-git/go-git#2074) - v5: git: submodule, error on remote without URLs by [@​hiddeco](https://github.com/hiddeco) in [#​2078](go-git/go-git#2078) - v5: plumbing: format/idxfile, Validate offset64 indices by [@​hiddeco](https://github.com/hiddeco) in [#​2084](go-git/go-git#2084) - v5: \*: Reject malformed variable-length integers by [@​hiddeco](https://github.com/hiddeco) in [#​2092](go-git/go-git#2092) - v5: plumbing: format/packfile, Tighten delta validation by [@​hiddeco](https://github.com/hiddeco) in [#​2091](go-git/go-git#2091) - v5: Add `worktreeFilesystem` wrapper for worktree and hardening by [@​hiddeco](https://github.com/hiddeco) in [#​2100](go-git/go-git#2100) - v5: config: validate submodule names by [@​hiddeco](https://github.com/hiddeco) in [#​2082](go-git/go-git#2082) - build: Update module github.com/go-git/go-git/v5 to v5.19.0 \[SECURITY] (releases/v5.x) by [@​go-git-renovate](https://github.com/go-git-renovate)\[bot] in [#​2111](go-git/go-git#2111) - v5: git: Allow MkdirAll on worktree-root paths by [@​hiddeco](https://github.com/hiddeco) in [#​2117](go-git/go-git#2117) - v5: git: Stop validating symlink target paths by [@​pjbgf](https://github.com/pjbgf) in [#​2116](go-git/go-git#2116) - v5: plumbing: format decoder input bounds and contracts by [@​hiddeco](https://github.com/hiddeco) in [#​2125](go-git/go-git#2125) - plumbing: format/packfile, cap delta chain depth in parser by [@​pjbgf](https://github.com/pjbgf) in [#​2137](go-git/go-git#2137) **Full Changelog**: <go-git/go-git@v5.19.0...v5.19.1> </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **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:eyJjcmVhdGVkSW5WZXIiOiI0My4xODIuMSIsInVwZGF0ZWRJblZlciI6IjQzLjE4Mi4xIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119--> Reviewed-on: https://gitea.com/gitea/runner/pulls/980 Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com> Co-authored-by: Renovate Bot <renovate-bot@gitea.com> Co-committed-by: Renovate Bot <renovate-bot@gitea.com>
Maks1mS
pushed a commit
to stplr-dev/stplr
that referenced
this pull request
May 20, 2026
This PR contains the following updates: | Package | Type | Update | Change | OpenSSF | |---|---|---|---|---| | [github.com/go-git/go-git/v5](https://github.com/go-git/go-git) | require | patch | `v5.19.0` → `v5.19.1` | [](https://securityscorecards.dev/viewer/?uri=github.com/go-git/go-git) | --- >⚠️ **Warning** > > Some dependencies could not be looked up. Check the [Dependency Dashboard](issues/23) for more information. --- ### Release Notes <details> <summary>go-git/go-git (github.com/go-git/go-git/v5)</summary> ### [`v5.19.1`](https://github.com/go-git/go-git/releases/tag/v5.19.1) [Compare Source](go-git/go-git@v5.19.0...v5.19.1) #### What's Changed - v5: plumbing: transport/ssh, Shell-quote path by [@​hiddeco](https://github.com/hiddeco) in [#​2068](go-git/go-git#2068) - v5: git: submodule, Fix relative URL resolution by [@​hiddeco](https://github.com/hiddeco) in [#​2070](go-git/go-git#2070) - v5: git: submodule, canonical remote for relative URLs by [@​hiddeco](https://github.com/hiddeco) in [#​2074](go-git/go-git#2074) - v5: git: submodule, error on remote without URLs by [@​hiddeco](https://github.com/hiddeco) in [#​2078](go-git/go-git#2078) - v5: plumbing: format/idxfile, Validate offset64 indices by [@​hiddeco](https://github.com/hiddeco) in [#​2084](go-git/go-git#2084) - v5: \*: Reject malformed variable-length integers by [@​hiddeco](https://github.com/hiddeco) in [#​2092](go-git/go-git#2092) - v5: plumbing: format/packfile, Tighten delta validation by [@​hiddeco](https://github.com/hiddeco) in [#​2091](go-git/go-git#2091) - v5: Add `worktreeFilesystem` wrapper for worktree and hardening by [@​hiddeco](https://github.com/hiddeco) in [#​2100](go-git/go-git#2100) - v5: config: validate submodule names by [@​hiddeco](https://github.com/hiddeco) in [#​2082](go-git/go-git#2082) - build: Update module github.com/go-git/go-git/v5 to v5.19.0 \[SECURITY] (releases/v5.x) by [@​go-git-renovate](https://github.com/go-git-renovate)\[bot] in [#​2111](go-git/go-git#2111) - v5: git: Allow MkdirAll on worktree-root paths by [@​hiddeco](https://github.com/hiddeco) in [#​2117](go-git/go-git#2117) - v5: git: Stop validating symlink target paths by [@​pjbgf](https://github.com/pjbgf) in [#​2116](go-git/go-git#2116) - v5: plumbing: format decoder input bounds and contracts by [@​hiddeco](https://github.com/hiddeco) in [#​2125](go-git/go-git#2125) - plumbing: format/packfile, cap delta chain depth in parser by [@​pjbgf](https://github.com/pjbgf) in [#​2137](go-git/go-git#2137) **Full Changelog**: <go-git/go-git@v5.19.0...v5.19.1> </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - At 12:00 AM through 04:59 AM and 10:00 PM through 11:59 PM, Monday through Friday (`* 0-4,22-23 * * 1-5`) - Only on Sunday and Saturday (`* * * * 0,6`) - Automerge - At any time (no schedule defined) 🚦 **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:eyJjcmVhdGVkSW5WZXIiOiI0My4xNzAuMjIiLCJ1cGRhdGVkSW5WZXIiOiI0My4xNzAuMjIiLCJ0YXJnZXRCcmFuY2giOiJtYWluIiwibGFiZWxzIjpbIktpbmQvRGVwZW5kZW5jaWVzIl19--> Reviewed-on: https://altlinux.space/stapler/stplr/pulls/435
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
A pack with a deeply chained delta sequence forced unbounded recursion during parse, letting a malformed input drive arbitrary stack growth. Walk the parent chain before each delta is resolved and reject anything beyond
4095links — the same ceiling upstream Git enforces viaOE_DEPTH_BITSinpack-objects.h, surfacingErrMalformedPackFile.Backport of #2113.