From patchwork Fri Oct 18 05:13:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Antipov X-Patchwork-Id: 13841087 X-Patchwork-Delegate: kuba@kernel.org Received: from forward203a.mail.yandex.net (forward203a.mail.yandex.net [178.154.239.90]) (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 5EEE11514CC for ; Fri, 18 Oct 2024 05:20:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.90 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729228846; cv=none; b=Hu7V/m+shyAnTRRBJb1JZI6FQ0+pPxdwRqBt27kkL6iqpnHEMqXwOyCNdx1qgsj0QqsNlXcjLPQlIFdBBdcvOUCKE8cYiaQaj9L8WYDUSoRlxexVEgRg7uJT0ZpUagmXBYy93i2khpTGKx8kTe2QaHCewfmFUnb/JS9HN/wxK8A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729228846; c=relaxed/simple; bh=KXvm92s07awak7G/cdC7TWsNdSrGe1cuAc+WzEpXq7M=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=C79881NHCjIlG/7Yak2S0qN4bcFFjgoCNHwSUJBVKxFTE33jldgyraWrlLP28wWJRdQSiM/SEQR0XfYtLOi4HQ05MKxLe4L3oBE8NbyMnV5I93JXtqImayaScMDRh+wnsbiAUFOtZQsvuvtZ1Gs7Tanr/LPRgXvyFPhvSHjh+3Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex.ru; spf=pass smtp.mailfrom=yandex.ru; dkim=pass (1024-bit key) header.d=yandex.ru header.i=@yandex.ru header.b=N4Q3JSHy; arc=none smtp.client-ip=178.154.239.90 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=yandex.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=yandex.ru header.i=@yandex.ru header.b="N4Q3JSHy" Received: from forward103a.mail.yandex.net (forward103a.mail.yandex.net [IPv6:2a02:6b8:c0e:500:1:45:d181:d103]) by forward203a.mail.yandex.net (Yandex) with ESMTPS id 8825E61393 for ; Fri, 18 Oct 2024 08:14:08 +0300 (MSK) Received: from mail-nwsmtp-smtp-production-main-84.vla.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-84.vla.yp-c.yandex.net [IPv6:2a02:6b8:c2a:1c1:0:640:adc:0]) by forward103a.mail.yandex.net (Yandex) with ESMTPS id C0D0060AD4; Fri, 18 Oct 2024 08:13:59 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-84.vla.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id vDGD1k31TSw0-nyUuekjI; Fri, 18 Oct 2024 08:13:58 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1729228438; bh=VMP8ChqrrEAjBj2IBe9W7mWr+cZyaoaLnScD0mdcSKM=; h=Message-ID:Date:Cc:Subject:To:From; b=N4Q3JSHyhVZDshMXIH3YCulkujqPJNkLt8W+q1N2QxkmvGOnykHR/hAv+q2527+Z+ +oS0yXuFvuT7pgMFIGYoYKC7cUH6MQkZCvkyqEK7JpaE0GdW1wl06+BsQJeNGVS9i2 rl8BxBY8jqvpdx3dWqMf+LdOKnW+WIGxXN3ovWEE= Authentication-Results: mail-nwsmtp-smtp-production-main-84.vla.yp-c.yandex.net; dkim=pass header.i=@yandex.ru From: Dmitry Antipov To: Vinicius Costa Gomes Cc: Jamal Hadi Salim , Cong Wang , Jiri Pirko , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, lvc-project@linuxtesting.org, Dmitry Antipov , syzbot+b65e0af58423fc8a73aa@syzkaller.appspotmail.com Subject: [PATCH net v7 1/2] net: sched: fix use-after-free in taprio_change() Date: Fri, 18 Oct 2024 08:13:38 +0300 Message-ID: <20241018051339.418890-1-dmantipov@yandex.ru> X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Yandex-Filter: 1 X-Patchwork-Delegate: kuba@kernel.org 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 --- v7: add (hopefully all required) process-related quirks v6: adjust to match recent changes v5: unchanged since v4 but resend due to series change v4: adjust subject to target net tree v3: unchanged since v2 v2: unchanged since v1 --- 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 8498d0606b24..9f4e004cdb8b 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1965,7 +1965,8 @@ 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);