From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C534C433B4 for ; Sun, 2 May 2021 14:04:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 707DA613D7 for ; Sun, 2 May 2021 14:04:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232689AbhEBOFQ (ORCPT ); Sun, 2 May 2021 10:05:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:49374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232198AbhEBOEb (ORCPT ); Sun, 2 May 2021 10:04:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 66C63613D2; Sun, 2 May 2021 14:03:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619964217; bh=s4bEDhrcdO7IwratN3VIoVQJwBOVOaLx+cy+meq0g8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oQygdp4CYK1guXyR/Ps/Zrv3K13dPkwFZoZ5iJMh+PrBAeVP3TRbBLPSmaFjxeeMh PR8L7mM5KPPMcLFvpTojXdedGj8FFeop8Av0Ef8PXpXtdT3MNzT/o7Zt54MM2swvpu X1JVKgdMRuTazH/ogn7NoFgJqYzSfapGOwMhayrlAP01IYngJ1CrRp/K64cw8XhM9A j9xJAEQhdnOiccx+AZyOacETNgmRrGjL/GSwRl5zKgnlylli39fKXl/rCaY1wijOg6 HFeU+FbxzG4wOHar9fiRETeGGVGmpJ59lmQrrx5JrDmfkzfS1Ud8E4imjAz3UoiHdu JV990J7ZTF2gw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 5.12 15/79] genirq/matrix: Prevent allocation counter corruption Date: Sun, 2 May 2021 10:02:12 -0400 Message-Id: <20210502140316.2718705-15-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210502140316.2718705-1-sashal@kernel.org> References: <20210502140316.2718705-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit c93a5e20c3c2dabef8ea360a3d3f18c6f68233ab ] When irq_matrix_free() is called for an unallocated vector the managed_allocated and total_allocated counters get out of sync with the real state of the matrix. Later, when the last interrupt is freed, these counters will underflow resulting in UINTMAX because the counters are unsigned. While this is certainly a problem of the calling code, this can be catched in the allocator by checking the allocation bit for the to be freed vector which simplifies debugging. An example of the problem described above: https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/ Add the missing sanity check and emit a warning when it triggers. Suggested-by: Thomas Gleixner Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com Signed-off-by: Sasha Levin --- kernel/irq/matrix.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c index 651a4ad6d711..8e586858bcf4 100644 --- a/kernel/irq/matrix.c +++ b/kernel/irq/matrix.c @@ -423,7 +423,9 @@ void irq_matrix_free(struct irq_matrix *m, unsigned int cpu, if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end)) return; - clear_bit(bit, cm->alloc_map); + if (WARN_ON_ONCE(!test_and_clear_bit(bit, cm->alloc_map))) + return; + cm->allocated--; if(managed) cm->managed_allocated--; -- 2.30.2