Ashwin Kumar Sivakumar 3e701f2fe6 fix: close two real money/spend races (Tracecoin double-credit, unbounded AI overspend) ... Asked to review Tracecoin and AI implementation safety. Found and fixed two exploitable TOCTOU races, plus a data-integrity bug: 1. apps/payments/src/main.rs::verify_payment — the PayU success callback is called directly by the client (not a server-to-server webhook), so a user fully controls how many times they replay a valid success payload. The payment "is it still PENDING" check and the "mark SUCCESS + credit wallet" write were separate, non-transactional queries — concurrent replays could both pass the check before either commits, double- (or N-times-) crediting the wallet for one real payment. Now wrapped in a single transaction with `SELECT ... FOR UPDATE` on the payments row, so a second concurrent call blocks until the first commits, then correctly sees the row is no longer PENDING (Postgres re-evaluates the WHERE clause via EvalPlanQual after the lock is granted). 2. crates/db/src/models/ai/repository.rs — UserAiSubscriptionRepository had the exact same shape of bug: apps/users/src/ai/credits.rs:: charge_feature read the subscription, checked daily-limit and credit balance, THEN issued two separate unconditional `UPDATE ... SET x = x + $1` statements with no WHERE guard on the balance. N concurrent requests from one user all pass the check before any deduction lands, running up unlimited LLM API spend (this endpoint is called before/around real LiteLLM calls, so the cost is real). Added UserAiSubscriptionRepository::try_charge — a single conditional UPDATE that checks the daily limit and credit balance and deducts atomically, returning None (mapped to the existing error types) if either check fails. 3. apps/cron/src/tasks/auto_apply.rs — daily_actions_used was being incremented twice per auto-applied job (once in the credit-deduct UPDATE, once more in a second, redundant UPDATE right after) — silently halving job seekers' effective daily auto-apply limit. Removed the redundant second UPDATE. Also added non-negative CHECK constraints directly to the live database (tracecoin_wallets.balance/reserved, user_ai_subscriptions.daily_actions_used/monthly_credits_used/ purchased_credits_used) as defense in depth — belt-and-suspenders in case a future code path reintroduces a similar bug.		2026-07-21 05:51:23 +05:30
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admin.rs	feat: human-readable reference numbers + fix verification document visibility	2026-07-19 16:34:00 +05:30
ai_credits.rs	fix: resolve payments package compilation errors	2026-07-06 02:32:14 +05:30
main.rs	fix: close two real money/spend races (Tracecoin double-credit, unbounded AI overspend)	2026-07-21 05:51:23 +05:30
packages.rs	feat: profile photo upload, PDF resume generation, AI auto-apply, schema fixes	2026-07-02 13:31:06 +02:00
payu.rs	feat: Complete Ask Ash AI Credits implementation on high-performance branch (Tasks 1-10)	2026-07-06 01:49:16 +05:30