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); From patchwork Fri Oct 18 05:13:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Antipov X-Patchwork-Id: 13841089 X-Patchwork-Delegate: kuba@kernel.org Received: from forward204a.mail.yandex.net (forward204a.mail.yandex.net [178.154.239.89]) (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 279AA17279E for ; Fri, 18 Oct 2024 05:21:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.89 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729228912; cv=none; b=hN9nbjxY4WDEPchI6TGdOlNDkZgl2jxdy5M0AWcBJz5GQhUv5RTzNJb0F42+c9CnN6d4WsZEpUycmYfUXVZ8tXNqVRK9YwAjcwHMMls4LO0V/4XJCFFqsY0mWheOAcj2ClhaRiQCRoCVscgm9tMV56wJW4EhF53LneRWP9RtgyU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729228912; c=relaxed/simple; bh=YYLUw1tsNAeW1RrlRIGcRwWZS7dM8hBu9T8fqSmK5YI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ei5P5su/0uB1SUl0j+KLZ+9kwhMB8bPVthA5ZWpgQiiIU31naA9H0B5OvBxb9H9hCaG8bQ3sZEehrCQGsq0E7g1H5knLjyc6t3Xt8MM+h2oWLSEJVx8Ji11k0rTLsc9Z0Nmssw4/7IQ9ZQdT8j7BGaEjIqxLnO6n4iUyRFmF0N0= 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=TZgLSPG9; arc=none smtp.client-ip=178.154.239.89 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="TZgLSPG9" Received: from forward101a.mail.yandex.net (forward101a.mail.yandex.net [IPv6:2a02:6b8:c0e:500:1:45:d181:d101]) by forward204a.mail.yandex.net (Yandex) with ESMTPS id AF68D6625D 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 forward101a.mail.yandex.net (Yandex) with ESMTPS id B3C3F60ABD; Fri, 18 Oct 2024 08:14:00 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-84.vla.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id vDGD1k31TSw0-WBbGJlEd; Fri, 18 Oct 2024 08:14:00 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1729228440; bh=FJiVCO64coyDGPLQKZPWSS+2s+d5qwfsR3PcXsBG+3A=; h=Message-ID:Date:In-Reply-To:Cc:Subject:References:To:From; b=TZgLSPG92zNHAxadWSJNqsGMTh0i6EF7I9W0amVAqDdGrn03tv6bhGVYylvp4dIGk 7XfkWWsoOjYhur0fHy2gIHw0boh/aM1kx0WWhL/EFDZo1oEKd4LYZgBRHIu4pEcc0c q03xVGKKPE7AYGiugkei8VHPkpsXKHzIQwaRZ1oc= 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 Subject: [PATCH net v7 2/2] net: sched: use RCU read-side critical section in taprio_dump() Date: Fri, 18 Oct 2024 08:13:39 +0300 Message-ID: <20241018051339.418890-2-dmantipov@yandex.ru> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241018051339.418890-1-dmantipov@yandex.ru> References: <20241018051339.418890-1-dmantipov@yandex.ru> 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 Fix possible use-after-free in 'taprio_dump()' by adding RCU read-side critical section there. Never seen on x86 but found on a KASAN-enabled arm64 system when investigating https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa: [T15862] BUG: KASAN: slab-use-after-free in taprio_dump+0xa0c/0xbb0 [T15862] Read of size 4 at addr ffff0000d4bb88f8 by task repro/15862 [T15862] [T15862] CPU: 0 UID: 0 PID: 15862 Comm: repro Not tainted 6.11.0-rc1-00293-gdefaf1a2113a-dirty #2 [T15862] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-20240524-5.fc40 05/24/2024 [T15862] Call trace: [T15862] dump_backtrace+0x20c/0x220 [T15862] show_stack+0x2c/0x40 [T15862] dump_stack_lvl+0xf8/0x174 [T15862] print_report+0x170/0x4d8 [T15862] kasan_report+0xb8/0x1d4 [T15862] __asan_report_load4_noabort+0x20/0x2c [T15862] taprio_dump+0xa0c/0xbb0 [T15862] tc_fill_qdisc+0x540/0x1020 [T15862] qdisc_notify.isra.0+0x330/0x3a0 [T15862] tc_modify_qdisc+0x7b8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Allocated by task 15857: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_alloc_info+0x40/0x60 [T15862] __kasan_kmalloc+0xd4/0xe0 [T15862] __kmalloc_cache_noprof+0x194/0x334 [T15862] taprio_change+0x45c/0x2fe0 [T15862] tc_modify_qdisc+0x6a8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Freed by task 6192: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_free_info+0x4c/0x80 [T15862] poison_slab_object+0x110/0x160 [T15862] __kasan_slab_free+0x3c/0x74 [T15862] kfree+0x134/0x3c0 [T15862] taprio_free_sched_cb+0x18c/0x220 [T15862] rcu_core+0x920/0x1b7c [T15862] rcu_core_si+0x10/0x1c [T15862] handle_softirqs+0x2e8/0xd64 [T15862] __do_softirq+0x14/0x20 Fixes: 18cdd2f0998a ("net/sched: taprio: taprio_dump and taprio_change are protected by rtnl_mutex") 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: add Fixes: and resend due to series change v4: redesign to preserve original code as much as possible, adjust commit message and subject to target net tree v3: tweak commit message as suggested by Vinicius v2: added to the series --- net/sched/sch_taprio.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 9f4e004cdb8b..8623dc0bafc0 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); @@ -2397,18 +2394,23 @@ 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 options_error_rcu; if (oper && dump_schedule(skb, oper)) - goto options_error; + goto options_error_rcu; if (!admin) goto done; sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED); if (!sched_nest) - goto options_error; + goto options_error_rcu; if (dump_schedule(skb, admin)) goto admin_error; @@ -2416,11 +2418,15 @@ static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb) nla_nest_end(skb, sched_nest); done: + rcu_read_unlock(); return nla_nest_end(skb, nest); admin_error: nla_nest_cancel(skb, sched_nest); +options_error_rcu: + rcu_read_unlock(); + options_error: nla_nest_cancel(skb, nest);