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 58BC6C43460 for ; Sun, 2 May 2021 14:06:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E429611EE for ; Sun, 2 May 2021 14:06:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233009AbhEBOHd (ORCPT ); Sun, 2 May 2021 10:07:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:50872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232511AbhEBOFh (ORCPT ); Sun, 2 May 2021 10:05:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B23D3613D4; Sun, 2 May 2021 14:04:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619964286; bh=s4bEDhrcdO7IwratN3VIoVQJwBOVOaLx+cy+meq0g8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b/bbNB+Hki02qjPXK64lHpJMtHIvh8TUClep/LNudz3tuMZyFJAxItMG3saEtwbq3 MB5gMlhrgzt/da3f2gkAIKBIPRvL0pgXo+I2uTPnp6Ijk6hrpOTxs+nVKqqfWR1Vv/ 9GyV78i6LEPtjyQnddgabNUC6hMR0QiFQSudElieShD45uEzq9VwmAqh3lBvAdXIBk NNoAosjivdN/qkAlmQwjNqjDstiI5ghZ7de3kCVn7CUC4uQQt3c5V7AhTlK/nwE4av 9pU1u5w9KH71dzYQq8MUaWTd8vgeMNrfijOZ0jzBtqvpK9XrhED2eC+AvbQy5r/dkK qV12yVJ3Tok5w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 5.4 09/34] genirq/matrix: Prevent allocation counter corruption Date: Sun, 2 May 2021 10:04:09 -0400 Message-Id: <20210502140434.2719553-9-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210502140434.2719553-1-sashal@kernel.org> References: <20210502140434.2719553-1-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