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 B1EC6C6FD1C for ; Fri, 24 Mar 2023 23:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232194AbjCXXOI (ORCPT ); Fri, 24 Mar 2023 19:14:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231986AbjCXXOB (ORCPT ); Fri, 24 Mar 2023 19:14:01 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14D7E166F8 for ; Fri, 24 Mar 2023 16:13:54 -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 ams.source.kernel.org (Postfix) with ESMTPS id 2F93EB82664 for ; Fri, 24 Mar 2023 23:13:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5C64C4339B; Fri, 24 Mar 2023 23:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679699631; bh=R5Dcu4im8mTB1GPdKaBdvzPMm6a86ne4BJngQDovN54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eeIcrvtDpYDnUDqqliP4EAVmyyIPgxKnxd3osuBpQSxt4alYmSHIMEGfQWkMQ4hQB d0Ilyrwn1MXrt04mApidkimT0IcuZ0zuiCZARnysbKrdoT7s/jZwHD7QbxFXgHFG5p kVzV0bQY5ZX+ZHwRxx4ehsRbW7GG/W6R1j/3sH0FBfLFWQyQpUsKGE2NZ9p8e/bcuq Jl9q8uHB0IcB12oeNTrfwK4lzRlp2Hkblw1REYH2uwW06iChCJ+4SFXeJmHAb9EYrd BJoa3M+lneIwo9WiDgbhO4BWQJ7I4FISiW6aBkWJWBX8x/ZC9gAxJnV0SxGaQCktr7 0BWo4JnY/HSBg== From: Saeed Mahameed To: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet Cc: Saeed Mahameed , netdev@vger.kernel.org, Tariq Toukan , Thomas Gleixner , Eli Cohen , Jacob Keller Subject: [net-next V2 01/15] lib: cpu_rmap: Avoid use after free on rmap->obj array entries Date: Fri, 24 Mar 2023 16:13:27 -0700 Message-Id: <20230324231341.29808-2-saeed@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230324231341.29808-1-saeed@kernel.org> References: <20230324231341.29808-1-saeed@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eli Cohen 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 --- 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 f08d9c56f712..e77f12bb3c77 100644 --- a/lib/cpu_rmap.c +++ b/lib/cpu_rmap.c @@ -232,7 +232,8 @@ 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); @@ -268,6 +269,7 @@ 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); } @@ -297,6 +299,7 @@ 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