From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66BFF611B for ; Sun, 28 May 2023 19:42:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6F4AC433EF; Sun, 28 May 2023 19:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685302945; bh=m8VNee3bA+lgpiWAyRUMwnimPC/EadPMf/JdyNqFKu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SWFgaUVVgf/5ab05IS8x5vsSmz35tLny+U86Hwi23lZRXlMBb5l5Xfwjzz/KNs47G dSnKhOxskM6DwD6Fc7a1MAcT0kdaleRD9SAcePFwwVx7NSt5T/xeT7i41azvbHqlL5 7H7tDDH4q3WFXLfsrJnDdtKGIBPr6DZq3KnLkqaY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Gleixner , Eli Cohen , Saeed Mahameed , Jacob Keller , Sasha Levin Subject: [PATCH 5.10 052/211] lib: cpu_rmap: Avoid use after free on rmap->obj array entries Date: Sun, 28 May 2023 20:09:33 +0100 Message-Id: <20230528190844.884642995@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230528190843.514829708@linuxfoundation.org> References: <20230528190843.514829708@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 f08d9c56f712e..e77f12bb3c774 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