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 A6817C43603 for ; Sun, 2 May 2021 14:06:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8780E613ED for ; Sun, 2 May 2021 14:06:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233610AbhEBOGv (ORCPT ); Sun, 2 May 2021 10:06:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:50382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232783AbhEBOFT (ORCPT ); Sun, 2 May 2021 10:05:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B0A45613DF; Sun, 2 May 2021 14:04:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619964268; bh=s4bEDhrcdO7IwratN3VIoVQJwBOVOaLx+cy+meq0g8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pDcSIi+7UcoUeDKTg1pDB1EXTRjcyI9dhWhAYSvA3Yrd8EOP8zdeXis3OCJhbAKar nc4lvtLuSQVotAkxg6wUBhsEOdVAz5ARqT4RFnbzI8sAyhrIOIIH/BlJ+sbe0ypY9e eczQj/CLyuHSMrUslS/flC+dy4HnpyR+DL4bUd+yEyuNQaThGL2jFcKMXWuHd4hRqq YQC5R98eHYgSK4kOmlgaezx0hgkmBZ5pqWjRxwsBCRWhImaB1iG3N9XqV6OkXFx4zA oLTIuwEFops/s2xCzT+vVw5IWV1mIVQwjXKUb2ycSRxFW5M8funisrnOKpWhJzPmSu HslKSytnKQyxg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 5.10 13/66] genirq/matrix: Prevent allocation counter corruption Date: Sun, 2 May 2021 10:03:18 -0400 Message-Id: <20210502140411.2719301-13-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210502140411.2719301-1-sashal@kernel.org> References: <20210502140411.2719301-1-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