From patchwork Fri Aug 30 10:16:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Antipov X-Patchwork-Id: 13784898 X-Patchwork-Delegate: kuba@kernel.org Received: from forward200b.mail.yandex.net (forward200b.mail.yandex.net [178.154.239.157]) (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 440DF175D4F for ; Fri, 30 Aug 2024 10:26:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725013580; cv=none; b=Sb8qhPKu2uYg3SFV4qS0PfgR5WUMZaZ+I3/f8npB8aOCCbhiMuNJ1fbeCpzFl/ubDtV6drMbbCyF1+p27wYehTFORuDxZzYlWGz0f8KG+QDavSMMKgRAC+T0zQeSpTNuAczxKZVOXbB5clGbjEg0takge/4H0D9Cqsr+c0l3d1E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725013580; c=relaxed/simple; bh=roV/mv/aUxwa/EDRQ0zJ9Euih3UQRBx13tut7ovFqeA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GJgmbPoknDHL8quHeh5Mw2m3K8lx3T6vzqWezZ2zVD/8pZGzewqrc+46LvSQ3A1gBVpn/LizmbdkvzVJArCCNF+c8Bz6Gw/VshAnwNiYcLsWv0dLC+/LCP+bwwe2KLrCCaoHF2xnQj2gO3vPNYrpwEL78UZobR9/h78KqzBRVeo= 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=ux0gnBbK; arc=none smtp.client-ip=178.154.239.157 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="ux0gnBbK" Received: from forward103b.mail.yandex.net (forward103b.mail.yandex.net [IPv6:2a02:6b8:c02:900:1:45:d181:d103]) by forward200b.mail.yandex.net (Yandex) with ESMTPS id AF293699C8 for ; Fri, 30 Aug 2024 13:19:05 +0300 (MSK) Received: from mail-nwsmtp-smtp-production-canary-88.sas.yp-c.yandex.net (mail-nwsmtp-smtp-production-canary-88.sas.yp-c.yandex.net [IPv6:2a02:6b8:c14:3483:0:640:1715:0]) by forward103b.mail.yandex.net (Yandex) with ESMTPS id 722CF608FE; Fri, 30 Aug 2024 13:18:58 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-canary-88.sas.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id rIUvxkaXxCg0-QhJR5T2D; Fri, 30 Aug 2024 13:18:56 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1725013136; bh=MnbpDdh85Wp2nRfqvzXdeXn+Ksd+K+6uCd7zhga5i+Y=; h=Message-ID:Date:In-Reply-To:Cc:Subject:References:To:From; b=ux0gnBbKl1fgtQiCgB6ZHMOqLFJL/OhzufHWaW/hbX3F/Jrn3Vq3/iOffu7HlR6Sf n0Ju35TEy3+DXKDtJj8qCJbZWa9mtQienBDytyZXbAdrpJCSaUpLAJucZZjkBe20Uh xr+3SmIU5/FDj2nmHyBhCvL6AXgTYfNJubwtk0Ro= Authentication-Results: mail-nwsmtp-smtp-production-canary-88.sas.yp-c.yandex.net; dkim=pass header.i=@yandex.ru From: Dmitry Antipov To: Vinicius Costa Gomes Cc: Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, lvc-project@linuxtesting.org, Dmitry Antipov Subject: [PATCH v3 3/3] net: sched: use RCU read-side critical section in taprio_dump() Date: Fri, 30 Aug 2024 13:16:33 +0300 Message-ID: <20240830101754.1574848-4-dmantipov@yandex.ru> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240830101754.1574848-1-dmantipov@yandex.ru> References: <20240830101754.1574848-1-dmantipov@yandex.ru> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Fix possible use-after-free in 'taprio_dump()' by adding RCU read-side critical section there. Never seen on x86 but reproduced on a KASAN-enabled arm64 system (note that original issue was found at https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa on arm64): [ 1601.079132][T15862] BUG: KASAN: slab-use-after-free in taprio_dump+0xa0c/0xbb0 [ 1601.082101][T15862] Read of size 4 at addr ffff0000d4bb88f8 by task repro/15862 [ 1601.085149][T15862] [ 1601.093445][T15862] CPU: 0 UID: 0 PID: 15862 Comm: repro Not tainted 6.11.0-rc1-00293-gdefaf1a2113a-dirty #2 [ 1601.100771][T15862] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-20240524-5.fc40 05/24/2024 [ 1601.106651][T15862] Call trace: [ 1601.107395][T15862] dump_backtrace+0x20c/0x220 [ 1601.108397][T15862] show_stack+0x2c/0x40 [ 1601.109220][T15862] dump_stack_lvl+0xf8/0x174 [ 1601.110041][T15862] print_report+0x170/0x4d8 [ 1601.110848][T15862] kasan_report+0xb8/0x1d4 [ 1601.111991][T15862] __asan_report_load4_noabort+0x20/0x2c [ 1601.112880][T15862] taprio_dump+0xa0c/0xbb0 [ 1601.113725][T15862] tc_fill_qdisc+0x540/0x1020 [ 1601.114586][T15862] qdisc_notify.isra.0+0x330/0x3a0 [ 1601.115506][T15862] tc_modify_qdisc+0x7b8/0x1838 [ 1601.116378][T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [ 1601.117320][T15862] netlink_rcv_skb+0x1f8/0x3d4 [ 1601.118164][T15862] rtnetlink_rcv+0x28/0x40 [ 1601.119037][T15862] netlink_unicast+0x51c/0x790 [ 1601.119874][T15862] netlink_sendmsg+0x79c/0xc20 [ 1601.120706][T15862] __sock_sendmsg+0xe0/0x1a0 [ 1601.121802][T15862] ____sys_sendmsg+0x6c0/0x840 [ 1601.122722][T15862] ___sys_sendmsg+0x1ac/0x1f0 [ 1601.123653][T15862] __sys_sendmsg+0x110/0x1d0 [ 1601.124459][T15862] __arm64_sys_sendmsg+0x74/0xb0 [ 1601.125316][T15862] invoke_syscall+0x88/0x2e0 [ 1601.126155][T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [ 1601.127051][T15862] do_el0_svc+0x44/0x60 [ 1601.127837][T15862] el0_svc+0x50/0x184 [ 1601.128639][T15862] el0t_64_sync_handler+0x120/0x12c [ 1601.129505][T15862] el0t_64_sync+0x190/0x194 [ 1601.130591][T15862] [ 1601.131361][T15862] Allocated by task 15857: [ 1601.132224][T15862] kasan_save_stack+0x3c/0x70 [ 1601.133193][T15862] kasan_save_track+0x20/0x3c [ 1601.134102][T15862] kasan_save_alloc_info+0x40/0x60 [ 1601.134955][T15862] __kasan_kmalloc+0xd4/0xe0 [ 1601.135965][T15862] __kmalloc_cache_noprof+0x194/0x334 [ 1601.136874][T15862] taprio_change+0x45c/0x2fe0 [ 1601.137859][T15862] tc_modify_qdisc+0x6a8/0x1838 [ 1601.138838][T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [ 1601.139799][T15862] netlink_rcv_skb+0x1f8/0x3d4 [ 1601.140664][T15862] rtnetlink_rcv+0x28/0x40 [ 1601.141725][T15862] netlink_unicast+0x51c/0x790 [ 1601.142662][T15862] netlink_sendmsg+0x79c/0xc20 [ 1601.143523][T15862] __sock_sendmsg+0xe0/0x1a0 [ 1601.144445][T15862] ____sys_sendmsg+0x6c0/0x840 [ 1601.145467][T15862] ___sys_sendmsg+0x1ac/0x1f0 [ 1601.146410][T15862] __sys_sendmsg+0x110/0x1d0 [ 1601.147293][T15862] __arm64_sys_sendmsg+0x74/0xb0 [ 1601.148116][T15862] invoke_syscall+0x88/0x2e0 [ 1601.148912][T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [ 1601.149754][T15862] do_el0_svc+0x44/0x60 [ 1601.150532][T15862] el0_svc+0x50/0x184 [ 1601.151438][T15862] el0t_64_sync_handler+0x120/0x12c [ 1601.152311][T15862] el0t_64_sync+0x190/0x194 [ 1601.153208][T15862] [ 1601.153751][T15862] Freed by task 6192: [ 1601.154491][T15862] kasan_save_stack+0x3c/0x70 [ 1601.155491][T15862] kasan_save_track+0x20/0x3c [ 1601.156521][T15862] kasan_save_free_info+0x4c/0x80 [ 1601.157357][T15862] poison_slab_object+0x110/0x160 [ 1601.158300][T15862] __kasan_slab_free+0x3c/0x74 [ 1601.159265][T15862] kfree+0x134/0x3c0 [ 1601.160068][T15862] taprio_free_sched_cb+0x18c/0x220 [ 1601.161046][T15862] rcu_core+0x920/0x1b7c [ 1601.161906][T15862] rcu_core_si+0x10/0x1c [ 1601.162693][T15862] handle_softirqs+0x2e8/0xd64 [ 1601.163518][T15862] __do_softirq+0x14/0x20 Signed-off-by: Dmitry Antipov --- v3: tweak commit message as suggested by Vinicius v2: added to the series --- net/sched/sch_taprio.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 9f4e004cdb8b..f31feca381c4 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -2374,9 +2374,6 @@ static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb) struct tc_mqprio_qopt opt = { 0 }; struct nlattr *nest, *sched_nest; - oper = rtnl_dereference(q->oper_sched); - admin = rtnl_dereference(q->admin_sched); - mqprio_qopt_reconstruct(dev, &opt); nest = nla_nest_start_noflag(skb, TCA_OPTIONS); @@ -2397,29 +2394,37 @@ static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb) nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay)) goto options_error; + rcu_read_lock(); + + oper = rtnl_dereference(q->oper_sched); + admin = rtnl_dereference(q->admin_sched); + if (oper && taprio_dump_tc_entries(skb, q, oper)) - goto options_error; + goto unlock; if (oper && dump_schedule(skb, oper)) - goto options_error; + goto unlock; - if (!admin) - goto done; + if (admin) { + sched_nest = + nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED); + if (!sched_nest) + goto unlock; - sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED); - if (!sched_nest) - goto options_error; + if (dump_schedule(skb, admin)) { + nla_nest_cancel(skb, sched_nest); + goto unlock; + } - if (dump_schedule(skb, admin)) - goto admin_error; + nla_nest_end(skb, sched_nest); + } - nla_nest_end(skb, sched_nest); + rcu_read_unlock(); -done: return nla_nest_end(skb, nest); -admin_error: - nla_nest_cancel(skb, sched_nest); +unlock: + rcu_read_unlock(); options_error: nla_nest_cancel(skb, nest);