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52ce2e6e85
On Linux/glibc, getaddrinfo_with_timeout() runs DNS asynchronously via getaddrinfo_a(GAI_NOWAIT) using a stack-local gaicb. When gai_suspend() hits the connection timeout, gai_cancel() is called and the function returns immediately — but gai_cancel() is non-blocking and can return EAI_NOTCANCELED, leaving the resolver worker thread alive and still referencing the destroyed stack frame. Adds three opt-in gtest cases (GetAddrInfoAsyncCancelTest.*) that exercise the cancel path repeatedly. They are gated on Linux/glibc + CPPHTTPLIB_USE_NON_BLOCKING_GETADDRINFO at compile time, and on the CPPHTTPLIB_TEST_ISSUE_2431=1 env var at runtime, so a normal `make test` run is unaffected. Also adds a dedicated CI job (issue-2431-repro) and a Docker-based local runner (test/run_issue_2431_repro.sh) that sinkhole UDP/53 so the timeout branch is taken, and run the test under ASAN/LSAN. With the bug present these runs are expected to fail; with a fix applied they should pass. Refs: https://github.com/yhirose/cpp-httplib/issues/2431 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
76 lines
2.7 KiB
Bash
Executable File
76 lines
2.7 KiB
Bash
Executable File
#!/usr/bin/env bash
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# Reproducer runner for Issue #2431
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# (https://github.com/yhirose/cpp-httplib/issues/2431).
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#
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# Spins up an Ubuntu container, points the resolver at a fake nameserver
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# that never replies (so getaddrinfo_a actually hits its timeout), builds
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# the test suite with g++ + ASAN, and runs the GetAddrInfoAsyncCancelTest
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# cases.
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#
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# Expected outcomes:
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# - HEAD prior to the fix: ASAN reports a use-after-free / heap-buffer
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# overflow during one of the GetAddrInfoAsyncCancelTest cases.
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# - HEAD with the fix applied: all three cases PASS.
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#
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# Usage:
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# bash test/run_issue_2431_repro.sh
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#
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# Requirements: Docker (Linux container support). The container needs
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# --privileged because the test binary uses `setarch -R` to disable ASLR
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# for ASAN compatibility, and because the script binds UDP/53 inside the
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# container.
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set -euo pipefail
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SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
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REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
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docker run --rm --privileged \
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-v "$REPO_ROOT:/work" \
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-w /work/test \
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ubuntu:24.04 bash -c '
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set -euo pipefail
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export DEBIAN_FRONTEND=noninteractive
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apt-get update -qq
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apt-get install -y -qq --no-install-recommends \
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ca-certificates g++ make pkg-config iptables util-linux coreutils file \
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libssl-dev zlib1g-dev libbrotli-dev libzstd-dev libcurl4-openssl-dev \
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>/dev/null
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# Force DNS-only resolution: Ubuntu defaults nsswitch.conf to
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# "hosts: files mdns4_minimal [NOTFOUND=return] dns ...", which
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# short-circuits to NOTFOUND before reaching glibc DNS code, so the
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# gai_cancel() branch never gets exercised.
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sed -i "s/^hosts:.*/hosts: dns/" /etc/nsswitch.conf
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# Drop all outbound UDP/53 traffic so DNS queries hang silently — this
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# matches the iptables-based setup in the original reproducer for
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# Issue #2431. Drop incoming responses too, in case anything sneaks
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# through (defense in depth).
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iptables -I OUTPUT -p udp --dport 53 -j DROP
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iptables -I INPUT -p udp --sport 53 -j DROP
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trap "iptables -D OUTPUT -p udp --dport 53 -j DROP 2>/dev/null; iptables -D INPUT -p udp --sport 53 -j DROP 2>/dev/null" EXIT
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# Sanity check: a real DNS lookup must hang (and time out) now.
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if timeout 2 getent hosts example.com >/dev/null 2>&1; then
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echo "ERROR: DNS unexpectedly resolved — DROP / nsswitch is not in effect" >&2
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exit 1
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fi
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echo "[ok] DNS UDP/53 is being dropped (expected for the repro)"
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cd /work/test
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echo "=== building test binary (g++ + ASAN) ==="
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make CXX=g++ test 2>&1 | tail -5
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ARCH=$(uname -m)
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echo "=== running GetAddrInfoAsyncCancelTest with CPPHTTPLIB_TEST_ISSUE_2431=1 ==="
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set +e
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CPPHTTPLIB_TEST_ISSUE_2431=1 setarch "$ARCH" -R \
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./test --gtest_filter="GetAddrInfoAsyncCancelTest.*" 2>&1
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rc=$?
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set -e
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echo "=== test exit: $rc ==="
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exit $rc
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'
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