promql/parser: fix panic on parenthesised number in offset_duration_expr by roidelapluie · Pull Request #18768 · prometheus/prometheus

roidelapluie · 2026-05-22T15:14:10Z

The unary_op LEFT_PAREN duration_expr RIGHT_PAREN production in offset_duration_expr unconditionally asserted $3.(*DurationExpr), but duration_expr can also reduce to a *NumberLiteral (e.g. the literal 0 or 5 inside parentheses). This caused a runtime panic recoverable only by the top-level recover in parse.go, which surfaced as an opaque "unexpected error".

Replace the hard type-assertion with a type switch matching the same pattern used by the unary_op duration_expr production in duration_expr: handle *DurationExpr (set Wrapped, negate if SUB) and *NumberLiteral (negate value if SUB, range-check, update pos), with a fallback parse error for unexpected node types.

Regenerate generated_parser.y.go from the updated grammar.

Add regression tests: foo offset +(5) and foo offset -(5) now parse correctly as ±5 s offsets.

Which issue(s) does the PR fix:

Release notes for end users (ALL commits must be considered).

Reviewers should verify clarity and quality.

[BUGFIX] PromQL: Fix panic when using a parenthesised plain number as an offset (e.g. `foo offset -(5)`)

The `unary_op LEFT_PAREN duration_expr RIGHT_PAREN` production in `offset_duration_expr` unconditionally asserted `$3.(*DurationExpr)`, but `duration_expr` can also reduce to a `*NumberLiteral` (e.g. the literal `0` or `5` inside parentheses). This caused a runtime panic recoverable only by the top-level recover in parse.go, which surfaced as an opaque "unexpected error". Replace the hard type-assertion with a type switch matching the same pattern used by the `unary_op duration_expr` production in `duration_expr`: handle `*DurationExpr` (set Wrapped, negate if SUB) and `*NumberLiteral` (negate value if SUB, range-check, update pos), with a fallback parse error for unexpected node types. Regenerate generated_parser.y.go from the updated grammar. Add regression tests: `foo offset +(5)` and `foo offset -(5)` now parse correctly as ±5 s offsets. Signed-off-by: Julien Pivotto <291750+roidelapluie@users.noreply.github.com>

…ession parsing Add durationLiteralOutOfRange to centralise the int64 nanosecond overflow check for numeric duration literals, replacing three identical inline conditions in the grammar. Add applyUnaryOpToDurationExpr to handle the unary +/- type-switch over *DurationExpr/*NumberLiteral, collapsing two near-identical grammar action blocks (offset_duration_expr and duration_expr) into single calls. Regenerate generated_parser.y.go. Signed-off-by: Julien Pivotto <291750+roidelapluie@users.noreply.github.com>

krajorama

LGTM

…➔ v3.13.0) (#1360) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [quay.io/prometheus/prometheus](https://github.com/prometheus/prometheus) | minor | `v3.12.0` → `v3.13.0` | --- ### Release Notes <details> <summary>prometheus/prometheus (quay.io/prometheus/prometheus)</summary> ### [`v3.13.0`](https://github.com/prometheus/prometheus/releases/tag/v3.13.0): 3.13.0 / 2026-07-01 [Compare Source](prometheus/prometheus@v3.12.0...v3.13.0) This is a Long Term Support [LTS](https://prometheus.io/docs/introduction/release-cycle/) release. - \[SECURITY] UI: Bump `sanitize-html` to fix a cross-site scripting vulnerability (CVE-2026-44990). [#18697](prometheus/prometheus#18697) - \[CHANGE] UI: Third-party npm dependency licenses are now embedded in the Prometheus binary and served at `/assets/third-party-licenses.txt`, replacing the `npm_licenses.tar.bz2` archive previously shipped in release tarballs and container images. [#18997](prometheus/prometheus#18997) - \[CHANGE] API: Use SHA-256 instead of SHA-1 to generate rule group pagination tokens. [#18927](prometheus/prometheus#18927) - \[CHANGE] HTTP clients: Credentials (Authorization header, basic auth, bearer token, OAuth2, configured headers) are no longer forwarded when following a redirect to a different host; affects scraping, remote read/write, alerting, and service discovery. Via prometheus/common v0.69.0 (CVE-2025-4673 CVE-2023-45289). [#18949](prometheus/prometheus#18949) - \[CHANGE] promtool: Relative file paths in the file passed to `--http.config.file` are now resolved relative to that config file's directory instead of its parent directory. Via prometheus/common v0.69.0. [#18949](prometheus/prometheus#18949) - \[CHANGE] PromQL: Rename the `min()` and `max()` duration-expression functions (experimental feature flag `experimental-duration-expr`) to `min_of()` and `max_of()` to avoid confusion with the `min` and `max` aggregate operators. [#18687](prometheus/prometheus#18687) - \[FEATURE] API: Add experimental search endpoints to search metric names, label names, and label values. [#18573](prometheus/prometheus#18573) - \[FEATURE] Discovery/AWS: Add ability to filter RDS instances. [#18859](prometheus/prometheus#18859) - \[FEATURE] PromQL: Add `min_of(a, b)` and `max_of(a, b)` scalar experimental functions, returning the smaller or larger of two scalar values. [#18687](prometheus/prometheus#18687) - \[FEATURE] PromQL: Add support for smoothed/anchored rate with native histograms. [#18564](prometheus/prometheus#18564) - \[FEATURE] PromQL: Expose per-query `samplesRead` (and `samplesReadPerStep` with `stats=all` and the `promql-per-step-stats` feature flag) in the query stats response, and add the `prometheus_engine_query_samples_read_total` engine counter. `samplesRead` reflects storage I/O distinct from `totalQueryableSamples`, which counts samples loaded into the evaluator (and so over-counts when a sample is reused across multiple range-vector windows). [#18081](prometheus/prometheus#18081) - \[FEATURE] Scrape: Add `__convert_classic_histograms_to_nhcb__` internal label to allow per-target override of `convert_classic_histograms_to_nhcb` scrape configuration via relabeling. [#18840](prometheus/prometheus#18840) - \[FEATURE] TSDB: Add `storage.tsdb.chunk_encoding.floats` configuration field to select float chunk encoding (`xor` or `xor2`) at runtime, independently of the `--enable-feature=xor2-encoding` flag. [#18769](prometheus/prometheus#18769) - \[FEATURE] remote\_write: Add Certificate support for ingesting data into an Azure Monitor Workspace. [#18217](prometheus/prometheus#18217) - \[FEATURE] Scrape: Add `__always_scrape_classic_histograms__` and `__scrape_native_histograms__` internal labels to allow per-target override of the `always_scrape_classic_histograms` and `scrape_native_histograms` scrape configuration via relabeling. [#18929](prometheus/prometheus#18929) - \[ENHANCEMENT] Release: Container images are now also published to the GitHub Container Registry (ghcr.io). [#18791](prometheus/prometheus#18791) - \[ENHANCEMENT] PromQL: Prettify `fill_left(x) fill_right(x)` as `fill(x)` when both fill values are equal. [#18851](prometheus/prometheus#18851) - \[ENHANCEMENT] UI: Improve autocompletion after closing a function bracket. [#18894](prometheus/prometheus#18894) - \[PERF] Labels: Add case-insensitive prefix matching to speed up evaluation of long case-insensitive regular expressions (up to \~2x faster). [#18540](prometheus/prometheus#18540) - \[PERF] TSDB: Reduce per-sample overhead in chunk population, speeding up affected queries by \~12-15% in benchmarks. [#18699](prometheus/prometheus#18699) - \[PERF] TSDB: Eliminate unnecessary heap allocations in the V2 histogram WAL decoder, reducing allocations by up to 50% and memory by up to 10% for deployments using native histograms with created-timestamp storage enabled (`--enable-feature=created-timestamp-zero-ingestion`). [#18813](prometheus/prometheus#18813) - \[BUGFIX] Discovery/AWS: Fix failure when processing an AWS RDS cluster without instances. [#18845](prometheus/prometheus#18845) - \[BUGFIX] Fix race condition in initTime that could cause ErrOutOfBounds. [#18629](prometheus/prometheus#18629) - \[BUGFIX] PromQL: A range query whose `end` was not aligned to `step` caused subqueries inside it to evaluate past the parent's last actual step, inflating `peakSamples` in the query stats and against the `query.max-samples` limit, and wasting storage I/O reading samples that were never used in the result. [#18081](prometheus/prometheus#18081) - \[BUGFIX] PromQL: A range query containing an at-modifier-unsafe function over a range-vector with an `@` modifier (e.g. `predict_linear(metric[60s] @ T, X)`) silently under-counted `totalQueryableSamples` for steps after step 0. [#18081](prometheus/prometheus#18081) - \[BUGFIX] PromQL: Fix `fill_left`/`fill_right` producing missing samples in range queries when using `group_left`/`group_right`. [#18850](prometheus/prometheus#18850) - \[BUGFIX] PromQL: Fix for resets() and changes() in anchored range extenders with histograms. [#18906](prometheus/prometheus#18906) - \[BUGFIX] PromQL: Fix panic on `1[5m] smoothed` and similar expressions when extended range selectors are enabled. [#18764](prometheus/prometheus#18764) - \[BUGFIX] PromQL: Fix panic when a `smoothed` instant vector selector produces no samples for a series. [#18943](prometheus/prometheus#18943) - \[BUGFIX] PromQL: Fix panic when using a parenthesised plain number as an offset (e.g. `foo offset -(5)`). [#18768](prometheus/prometheus#18768) - \[BUGFIX] promtool: Fix panic when parsing exposition text containing empty braces `{}`. Via prometheus/common v0.69.0. [#18949](prometheus/prometheus#18949) - \[BUGFIX] Promtool: Fix `check healthy` and `check ready` when `--url` ends with a trailing slash. [#18854](prometheus/prometheus#18854) - \[BUGFIX] Rules: Close PromQL query after each rule evaluation to ensure resources are released. [#18733](prometheus/prometheus#18733) - \[BUGFIX] Scaleway SD: Resolve VPC/IPAM-only instances that have no legacy `private_ip` or `public_ip` field, but do have private NICs attached. [#18772](prometheus/prometheus#18772) - \[BUGFIX] TSDB: Do not leak head series when an integer histogram append is rejected (e.g. out-of-order). [#18838](prometheus/prometheus#18838) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] TSDB: Fix chunk snapshot encoding for EncXOR2 chunks, preventing corruption on TSDB restart when EncXOR2-encoded series were present. [#18739](prometheus/prometheus#18739) - \[BUGFIX] TSDB: Store a millisecond timestamp (not a WAL segment number) in walExpiries when a series is evicted via CompactStaleHead/CompactSelectedSeries, so the series's label record is correctly retained in the next WAL checkpoint and replays cleanly. [#18847](prometheus/prometheus#18847) - \[BUGFIX] TSDB: Prevent loss of samples at the chunk-range boundary when CompactSelectedSeries (and CompactStaleHead) evict the series — the per-slice compaction loop now runs one more iteration so the boundary timestamp is captured in a block before the in-memory copy is removed. [#18849](prometheus/prometheus#18849) </details> --- ### Configuration 📅 **Schedule**: 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 these updates again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.erwanleboucher.dev/eleboucher/homelab/pulls/1360

##### [\`v3.13.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.13.0) This is a Long Term Support [LTS](https://prometheus.io/docs/introduction/release-cycle/) release. - \[SECURITY] UI: Bump `sanitize-html` to fix a cross-site scripting vulnerability (CVE-2026-44990). [#18697](prometheus/prometheus#18697) - \[CHANGE] UI: Third-party npm dependency licenses are now embedded in the Prometheus binary and served at `/assets/third-party-licenses.txt`, replacing the `npm_licenses.tar.bz2` archive previously shipped in release tarballs and container images. [#18997](prometheus/prometheus#18997) - \[CHANGE] API: Use SHA-256 instead of SHA-1 to generate rule group pagination tokens. [#18927](prometheus/prometheus#18927) - \[CHANGE] HTTP clients: Credentials (Authorization header, basic auth, bearer token, OAuth2, configured headers) are no longer forwarded when following a redirect to a different host; affects scraping, remote read/write, alerting, and service discovery. Via prometheus/common v0.69.0 (CVE-2025-4673 CVE-2023-45289). [#18949](prometheus/prometheus#18949) - \[CHANGE] promtool: Relative file paths in the file passed to `--http.config.file` are now resolved relative to that config file's directory instead of its parent directory. Via prometheus/common v0.69.0. [#18949](prometheus/prometheus#18949) - \[CHANGE] PromQL: Rename the `min()` and `max()` duration-expression functions (experimental feature flag `experimental-duration-expr`) to `min_of()` and `max_of()` to avoid confusion with the `min` and `max` aggregate operators. [#18687](prometheus/prometheus#18687) - \[FEATURE] API: Add experimental search endpoints to search metric names, label names, and label values. [#18573](prometheus/prometheus#18573) - \[FEATURE] Discovery/AWS: Add ability to filter RDS instances. [#18859](prometheus/prometheus#18859) - \[FEATURE] PromQL: Add `min_of(a, b)` and `max_of(a, b)` scalar experimental functions, returning the smaller or larger of two scalar values. [#18687](prometheus/prometheus#18687) - \[FEATURE] PromQL: Add support for smoothed/anchored rate with native histograms. [#18564](prometheus/prometheus#18564) - \[FEATURE] PromQL: Expose per-query `samplesRead` (and `samplesReadPerStep` with `stats=all` and the `promql-per-step-stats` feature flag) in the query stats response, and add the `prometheus_engine_query_samples_read_total` engine counter. `samplesRead` reflects storage I/O distinct from `totalQueryableSamples`, which counts samples loaded into the evaluator (and so over-counts when a sample is reused across multiple range-vector windows). [#18081](prometheus/prometheus#18081) - \[FEATURE] Scrape: Add `__convert_classic_histograms_to_nhcb__` internal label to allow per-target override of `convert_classic_histograms_to_nhcb` scrape configuration via relabeling. [#18840](prometheus/prometheus#18840) - \[FEATURE] TSDB: Add `storage.tsdb.chunk_encoding.floats` configuration field to select float chunk encoding (`xor` or `xor2`) at runtime, independently of the `--enable-feature=xor2-encoding` flag. [#18769](prometheus/prometheus#18769) - \[FEATURE] remote\_write: Add Certificate support for ingesting data into an Azure Monitor Workspace. [#18217](prometheus/prometheus#18217) - \[FEATURE] Scrape: Add `__always_scrape_classic_histograms__` and `__scrape_native_histograms__` internal labels to allow per-target override of the `always_scrape_classic_histograms` and `scrape_native_histograms` scrape configuration via relabeling. [#18929](prometheus/prometheus#18929) - \[ENHANCEMENT] Release: Container images are now also published to the GitHub Container Registry (ghcr.io). [#18791](prometheus/prometheus#18791) - \[ENHANCEMENT] PromQL: Prettify `fill_left(x) fill_right(x)` as `fill(x)` when both fill values are equal. [#18851](prometheus/prometheus#18851) - \[ENHANCEMENT] UI: Improve autocompletion after closing a function bracket. [#18894](prometheus/prometheus#18894) - \[PERF] Labels: Add case-insensitive prefix matching to speed up evaluation of long case-insensitive regular expressions (up to \~2x faster). [#18540](prometheus/prometheus#18540) - \[PERF] TSDB: Reduce per-sample overhead in chunk population, speeding up affected queries by \~12-15% in benchmarks. [#18699](prometheus/prometheus#18699) - \[PERF] TSDB: Eliminate unnecessary heap allocations in the V2 histogram WAL decoder, reducing allocations by up to 50% and memory by up to 10% for deployments using native histograms with created-timestamp storage enabled (`--enable-feature=created-timestamp-zero-ingestion`). [#18813](prometheus/prometheus#18813) - \[BUGFIX] Discovery/AWS: Fix failure when processing an AWS RDS cluster without instances. [#18845](prometheus/prometheus#18845) - \[BUGFIX] Fix race condition in initTime that could cause ErrOutOfBounds. [#18629](prometheus/prometheus#18629) - \[BUGFIX] PromQL: A range query whose `end` was not aligned to `step` caused subqueries inside it to evaluate past the parent's last actual step, inflating `peakSamples` in the query stats and against the `query.max-samples` limit, and wasting storage I/O reading samples that were never used in the result. [#18081](prometheus/prometheus#18081) - \[BUGFIX] PromQL: A range query containing an at-modifier-unsafe function over a range-vector with an `@` modifier (e.g. `predict_linear(metric[60s] @ T, X)`) silently under-counted `totalQueryableSamples` for steps after step 0. [#18081](prometheus/prometheus#18081) - \[BUGFIX] PromQL: Fix `fill_left`/`fill_right` producing missing samples in range queries when using `group_left`/`group_right`. [#18850](prometheus/prometheus#18850) - \[BUGFIX] PromQL: Fix for resets() and changes() in anchored range extenders with histograms. [#18906](prometheus/prometheus#18906) - \[BUGFIX] PromQL: Fix panic on `1[5m] smoothed` and similar expressions when extended range selectors are enabled. [#18764](prometheus/prometheus#18764) - \[BUGFIX] PromQL: Fix panic when a `smoothed` instant vector selector produces no samples for a series. [#18943](prometheus/prometheus#18943) - \[BUGFIX] PromQL: Fix panic when using a parenthesised plain number as an offset (e.g. `foo offset -(5)`). [#18768](prometheus/prometheus#18768) - \[BUGFIX] promtool: Fix panic when parsing exposition text containing empty braces `{}`. Via prometheus/common v0.69.0. [#18949](prometheus/prometheus#18949) - \[BUGFIX] Promtool: Fix `check healthy` and `check ready` when `--url` ends with a trailing slash. [#18854](prometheus/prometheus#18854) - \[BUGFIX] Rules: Close PromQL query after each rule evaluation to ensure resources are released. [#18733](prometheus/prometheus#18733) - \[BUGFIX] Scaleway SD: Resolve VPC/IPAM-only instances that have no legacy `private_ip` or `public_ip` field, but do have private NICs attached. [#18772](prometheus/prometheus#18772) - \[BUGFIX] TSDB: Do not leak head series when an integer histogram append is rejected (e.g. out-of-order). [#18838](prometheus/prometheus#18838) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] TSDB: Fix chunk snapshot encoding for EncXOR2 chunks, preventing corruption on TSDB restart when EncXOR2-encoded series were present. [#18739](prometheus/prometheus#18739) - \[BUGFIX] TSDB: Store a millisecond timestamp (not a WAL segment number) in walExpiries when a series is evicted via CompactStaleHead/CompactSelectedSeries, so the series's label record is correctly retained in the next WAL checkpoint and replays cleanly. [#18847](prometheus/prometheus#18847) - \[BUGFIX] TSDB: Prevent loss of samples at the chunk-range boundary when CompactSelectedSeries (and CompactStaleHead) evict the series — the per-slice compaction loop now runs one more iteration so the boundary timestamp is captured in a block before the in-memory copy is removed. [#18849](prometheus/prometheus#18849)

roidelapluie requested a review from a team as a code owner May 22, 2026 15:14

roidelapluie requested review from ArthurSens and krajorama May 22, 2026 15:14

krajorama approved these changes May 22, 2026

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krajorama mentioned this pull request May 22, 2026

promql/parser: parentheses around a plain duration literal are lost on round-trip #18770

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roidelapluie merged commit 74b3ba5 into prometheus:main May 22, 2026
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promql/parser: fix panic on parenthesised number in offset_duration_expr#18768

promql/parser: fix panic on parenthesised number in offset_duration_expr#18768
roidelapluie merged 2 commits into
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roidelapluie:roidelapluie/panic-parent-dur-expr

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