Guard against nullptr dereference when checking concurrent solver status - #1845
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If dual simplex or barrier did not set their solution pointers (e.g. on early termination, error, or limit), dereferencing sol_dual_simplex_ptr or sol_barrier_ptr directly causes a null pointer dereference.
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Included review availability: Your plan provides up to 12 included reviews per hour; 10 remain after this review. 📝 WalkthroughWalkthroughThe concurrent solver now handles missing dual-simplex and barrier results without null dereferences. Concurrent MIP tests cover null solver pointers, halt handling, and OpenMP thread restoration. ChangesConcurrent solver status handling
Priority: ⬇️ Low Estimated code review effort: 2 (Simple) | ~10 minutes Change: Bug fix Suggested reviewers: Merge Risk: ⚪ Minimal · up to The concurrent-solver safety changes and their regression coverage have no remaining actionable merge risk. 🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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In `@cpp/src/pdlp/solve.cu`:
- Around line 1706-1713: Add regression tests under the existing gtest patterns
in cpp/src/tests for concurrent solves with dual simplex inactive and barrier
disabled, including early-termination or limit scenarios. Verify null
sol_dual_simplex_ptr and sol_barrier_ptr paths produce
simplex::lp_status_t::CONCURRENT_LIMIT and complete without dereferencing null
pointers, covering the status-selection logic in the solve flow.
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sylvesterkaczmarek
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sol_dual_simplex_ptr is still unconditionally dereferenced in the later PDLP ConcurrentLimit branch. If dual simplex produced no result, the new status guard maps it to CONCURRENT_LIMIT, but this branch then does *sol_dual_simplex_ptr anyway and can still crash. Please guard/fallback there too and add a null-result ConcurrentLimit regression.
…ion tests
- Guard sol_dual_simplex_ptr dereference in run_concurrent's ConcurrentLimit branch
when dual simplex produced no result.
- Add Doxygen docstring to run_concurrent.
- Add regression tests in pdlp_test.cu:
- concurrent_null_solver_ptrs_inside_mip: verifies concurrent solves when both
dual simplex and barrier are inactive/disabled.
- concurrent_null_dual_simplex_concurrent_limit: verifies ConcurrentLimit handling
when dual simplex produced no result.
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Great points, done! |
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Inline comments:
In `@cpp/tests/linear_programming/pdlp_test.cu`:
- Around line 198-200: Update the test setup around solve_lp and the existing
prev_threads value to use an RAII cleanup guard that restores the OpenMP thread
count on every exit path, including uncaught exceptions. Preserve the current
normal-path restoration while ensuring the guard is released only after
omp_set_num_threads(prev_threads) executes.
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Thanks, appreciate the quick turnaround. The null ConcurrentLimit dereference I flagged is fixed, and the new regression exercises the no-dual-simplex path. I see the separate RAII test-cleanup comment as well; that's independent of my concern. |
hlinsen
added
bug
… depend on OpenMP.
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Inline comments:
In `@cpp/tests/linear_programming/pdlp_test.cu`:
- Line 200: Remove the duplicate prev_threads declaration near the later OpenMP
setup, keeping the original declaration and value used by restore_threads to
restore the initial thread setting.
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… depend on OpenMP.
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/ok to test 21baba7 |
CI Test Summary✅ All 31 test job(s) passed. |
Signed-off-by: Hugo Linsenmaier <15280931+hlinsen@users.noreply.github.com>
Signed-off-by: Hugo Linsenmaier <15280931+hlinsen@users.noreply.github.com>
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/ok to test bf40ede |
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/merge |
3 participants
If dual simplex or barrier did not set their solution pointers (e.g. on early termination, error, or limit), dereferencing sol_dual_simplex_ptr or sol_barrier_ptr directly causes a null pointer dereference.
Full disclosure: done with the help of Gemini AI.
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