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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BB32C7EE2A for ; Thu, 4 May 2023 20:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232685AbjEDUG5 (ORCPT ); Thu, 4 May 2023 16:06:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232711AbjEDUFC (ORCPT ); Thu, 4 May 2023 16:05:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0414E23A35; Thu, 4 May 2023 12:52:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D26236386A; Thu, 4 May 2023 19:51:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72640C433D2; Thu, 4 May 2023 19:51:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683229912; bh=m51mPhvK+CqdrYQsaeKqNgmOl9Z79RIoIWygm3wIsJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DcT8Exb2JyTOXKk+xCBEETmq0O69koNhckNnfh8c4+55HszE+uYEYELBRJeZVVnzg /QFjtr6KOTiEkZDF1iISdsM3DIiRej06KQ44852HzFFwHC2xi9viIp86lQlSliq8jK t6OG/F/qlnNAH5qVa/IDFvE2cK0LalOlno9GBLmhYP2ieMEjngW2kYVU27JDtq4Aap AjIiXHu7ma3T2APGxwJ2FIVZf6mUAa8I5dzttZG1Jv1k9GJtLnDTJqULPYlHUgwIPR QTs+A6va83MxpbbFznM+7ugj5/Hjx8GPmGi6oWYXooDoMTp3GKPR/hH7in0kQXwV57 Dwc+G5DDlyJqQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eli Cohen , Thomas Gleixner , Saeed Mahameed , Jacob Keller , Sasha Levin Subject: [PATCH AUTOSEL 4.19 06/13] lib: cpu_rmap: Avoid use after free on rmap->obj array entries Date: Thu, 4 May 2023 15:51:23 -0400 Message-Id: <20230504195132.3808946-6-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230504195132.3808946-1-sashal@kernel.org> References: <20230504195132.3808946-1-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: Eli Cohen [ Upstream commit 4e0473f1060aa49621d40a113afde24818101d37 ] When calling irq_set_affinity_notifier() with NULL at the notify argument, it will cause freeing of the glue pointer in the corresponding array entry but will leave the pointer in the array. A subsequent call to free_irq_cpu_rmap() will try to free this entry again leading to possible use after free. Fix that by setting NULL to the array entry and checking that we have non-zero at the array entry when iterating over the array in free_irq_cpu_rmap(). The current code does not suffer from this since there are no cases where irq_set_affinity_notifier(irq, NULL) (note the NULL passed for the notify arg) is called, followed by a call to free_irq_cpu_rmap() so we don't hit and issue. Subsequent patches in this series excersize this flow, hence the required fix. Cc: Thomas Gleixner Signed-off-by: Eli Cohen Signed-off-by: Saeed Mahameed Reviewed-by: Jacob Keller Signed-off-by: Sasha Levin --- lib/cpu_rmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c index f610b2a10b3ed..f52389054a24f 100644 --- a/lib/cpu_rmap.c +++ b/lib/cpu_rmap.c @@ -235,7 +235,8 @@ void free_irq_cpu_rmap(struct cpu_rmap *rmap) for (index = 0; index < rmap->used; index++) { glue = rmap->obj[index]; - irq_set_affinity_notifier(glue->notify.irq, NULL); + if (glue) + irq_set_affinity_notifier(glue->notify.irq, NULL); } cpu_rmap_put(rmap); @@ -271,6 +272,7 @@ static void irq_cpu_rmap_release(struct kref *ref) container_of(ref, struct irq_glue, notify.kref); cpu_rmap_put(glue->rmap); + glue->rmap->obj[glue->index] = NULL; kfree(glue); } @@ -300,6 +302,7 @@ int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq) rc = irq_set_affinity_notifier(irq, &glue->notify); if (rc) { cpu_rmap_put(glue->rmap); + rmap->obj[glue->index] = NULL; kfree(glue); } return rc; -- 2.39.2