From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 7EAFC1FF137 for ; Tue, 03 Mar 2026 08:15:00 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 66CD1CA37; Tue, 3 Mar 2026 08:16:02 +0100 (CET) From: Hannes Laimer To: pve-devel@lists.proxmox.com Subject: [PATCH pve-common] RESTEnvironment: fix possible race in `register_worker` Date: Tue, 3 Mar 2026 08:15:26 +0100 Message-ID: <20260303071526.1150-1-h.laimer@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1772522103919 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.999 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.66 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.968 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.495 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: PTJ4BFHKW5AOCI6KB5X5SJIK26GYSTTF X-Message-ID-Hash: PTJ4BFHKW5AOCI6KB5X5SJIK26GYSTTF X-MailFrom: h.laimer@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: If the worker finishes right after we `waitpid` but before we add it to `WORKER_PIDS` the `worker_reaper` won't `waitpid` it cause it iterates over `WORKER_PIDS`. So - the clean-up triggered by the SIGCHLD won't catch it cause it needs it to be in `WORKER_PIDS` - and, `register_worker` won't because it was still running when it `waitpid`'ed it Moving the insertion into `WORKER_PIDS` before the `waitpid` solves this by making sure it is - always in the var for `worker_reaper` - and, if SIGCHILD should trigger `worker_reaper` before we add it to `WORKER_PIDS`, the `waitpid` in `register_worker` itself will catch it Signed-off-by: Hannes Laimer --- src/PVE/RESTEnvironment.pm | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/src/PVE/RESTEnvironment.pm b/src/PVE/RESTEnvironment.pm index 4ed5c05..4677687 100644 --- a/src/PVE/RESTEnvironment.pm +++ b/src/PVE/RESTEnvironment.pm @@ -99,17 +99,18 @@ my $register_worker = sub { return if !$pid; - # do not register if already finished + $WORKER_PIDS->{$pid} = { + user => $user, + upid => $upid, + }; + + # remove immediately if already finished my $waitpid = waitpid($pid, WNOHANG); if (defined($waitpid) && ($waitpid == $pid)) { delete($WORKER_PIDS->{$pid}); return; } - $WORKER_PIDS->{$pid} = { - user => $user, - upid => $upid, - }; }; # initialize environment - must be called once at program startup -- 2.47.3