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 D318B18E35B; Mon, 28 Oct 2024 06:43:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730097801; cv=none; b=X/0k8qSk0uKE0L2xBFbnlC+Uj6anDQuK6ZtrAtAqw7/fcXn/fRw5EncdojRmxu0KzQ+VA5LWJb9nOFgyw3ZgKb/eGy3KhMujWeCrtiFWf7gzq4mdVaS9kJAZ3quqv1q+KAGpV6dP7HHfIo3o5cwzvDnkkNi3ZdImFPDP6s72UfY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730097801; c=relaxed/simple; bh=Y9CjdeMoP0McwqqNtxgNy7xRfuOCdG2QVEusfj+Yzeo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GLO95eYTOmNhWWoCj+9oUBvMqX6Mb97it9j6rXntaOKhsa9n3yNT3MAZDMfFgpZGL1rUFvHZoyMTPv4mFeCrIWL7h7X3vzVqftxj3UVetO1/a6Cis3fC3boWAVGp6hCx3iYGLsqik9bRuDI7LiUrlVVo7oByyBRuvAAU0Nq5Ufs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fpbTq5Cm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fpbTq5Cm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 732A3C4CEC3; Mon, 28 Oct 2024 06:43:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730097801; bh=Y9CjdeMoP0McwqqNtxgNy7xRfuOCdG2QVEusfj+Yzeo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fpbTq5CmZt9JxOHG31/9CWcV6xYVkpN5YwOTZHY5WkTWVWTczSSCNSMh+mo/JiUN8 QQ0lOQSwT0qbsH6oC5Tm5WjkFp4pM0/woriQmQ/UQPl8ST2zCGZ1nig91B6AZ2prAx kKVdFCB9MugZyUPyjkLIeg39qd+pOMq8o+I7Uqa4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+b65e0af58423fc8a73aa@syzkaller.appspotmail.com, Vinicius Costa Gomes , Dmitry Antipov , Paolo Abeni , Sasha Levin Subject: [PATCH 6.6 154/208] net: sched: fix use-after-free in taprio_change() Date: Mon, 28 Oct 2024 07:25:34 +0100 Message-ID: <20241028062310.417646682@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028062306.649733554@linuxfoundation.org> References: <20241028062306.649733554@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Antipov [ Upstream commit f504465970aebb2467da548f7c1efbbf36d0f44b ] In 'taprio_change()', 'admin' pointer may become dangling due to sched switch / removal caused by 'advance_sched()', and critical section protected by 'q->current_entry_lock' is too small to prevent from such a scenario (which causes use-after-free detected by KASAN). Fix this by prefer 'rcu_replace_pointer()' over 'rcu_assign_pointer()' to update 'admin' immediately before an attempt to schedule freeing. Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule") Reported-by: syzbot+b65e0af58423fc8a73aa@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa Acked-by: Vinicius Costa Gomes Signed-off-by: Dmitry Antipov Link: https://patch.msgid.link/20241018051339.418890-1-dmantipov@yandex.ru Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/sched/sch_taprio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 87090d6790362..bc8e55c6d63d1 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1988,7 +1988,8 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, taprio_start_sched(sch, start, new_admin); - rcu_assign_pointer(q->admin_sched, new_admin); + admin = rcu_replace_pointer(q->admin_sched, new_admin, + lockdep_rtnl_is_held()); if (admin) call_rcu(&admin->rcu, taprio_free_sched_cb); -- 2.43.0