From patchwork Fri Dec 9 08:22:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ding Hui X-Patchwork-Id: 633172 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07001C4332F for ; Fri, 9 Dec 2022 08:28:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229731AbiLII2x (ORCPT ); Fri, 9 Dec 2022 03:28:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229563AbiLII2u (ORCPT ); Fri, 9 Dec 2022 03:28:50 -0500 X-Greylist: delayed 320 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 09 Dec 2022 00:28:49 PST Received: from mail-m12746.qiye.163.com (mail-m12746.qiye.163.com [115.236.127.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17B615E3FE for ; Fri, 9 Dec 2022 00:28:48 -0800 (PST) Received: from localhost.localdomain (unknown [IPV6:240e:3b7:3278:a320:2d2e:ae7d:96bb:1e55]) by mail-m12746.qiye.163.com (Hmail) with ESMTPA id D24AEBC04AF; Fri, 9 Dec 2022 16:23:22 +0800 (CST) From: Ding Hui To: lduncan@suse.com, cleech@redhat.com, michael.christie@oracle.com, jejb@linux.ibm.com, martin.petersen@oracle.com, open-iscsi@googlegroups.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ding Hui Subject: [PATCH] scsi: iscsi_tcp: Fix UAF when access shost attr during session logout Date: Fri, 9 Dec 2022 16:22:47 +0800 Message-Id: <20221209082247.6330-1-dinghui@sangfor.com.cn> X-Mailer: git-send-email 2.17.1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWS1ZQUlXWQ8JGhUIEh9ZQVkZGU9CVh9LT09IHRgeSEtNGVUTARMWGhIXJBQOD1 lXWRgSC1lBWUlPSx5BSBlMQUhJTENBGkhJS0FJH0keQRoeTB9BQk0ZGUFKHk5OWVdZFhoPEhUdFF lBWU9LSFVKSktPSEhVSktLVUtZBg++ X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6MU06Mxw4Ez0jT0s1I00DDRBL LzQaCxBVSlVKTUxLTkxPSUtITU5JVTMWGhIXVR8SFRwTDhI7CBoVHB0UCVUYFBZVGBVFWVdZEgtZ QVlJT0seQUgZTEFISUxDQRpISUtBSR9JHkEaHkwfQUJNGRlBSh5OTllXWQgBWUFMTUxKNwY+ X-HM-Tid: 0a84f5fb60f9b219kuuud24aebc04af Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org During iscsi session logout, if another task accessing shost ipaddress attr at this time, we can get a KASAN UAF report like this: [ 276.941685] ================================================================== [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat ----------------------------------+------------------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release | |- dev_attr_show |- kfree | |- show_host_param_ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Since shost hold a pointer to session which is belong to cls_session by its priv tcp_sw_host, so we should get a ref of cls_session, and after iscsi_host_remove() the sysfs is cleared, then we can drop the ref. Signed-off-by: Ding Hui --- drivers/scsi/iscsi_tcp.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index 5fb1f364e815..752ef9ccd715 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -959,6 +959,8 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, goto remove_host; session = cls_session->dd_data; tcp_sw_host = iscsi_host_priv(shost); + /* hold refcount for tcp_sw_host */ + get_device(&cls_session->dev); tcp_sw_host->session = session; if (iscsi_tcp_r2tpool_alloc(session)) @@ -966,6 +968,7 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, return cls_session; remove_session: + put_device(&cls_session->dev); iscsi_session_teardown(cls_session); remove_host: iscsi_host_remove(shost, false); @@ -978,6 +981,7 @@ static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) { struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); struct iscsi_session *session = cls_session->dd_data; + struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); if (WARN_ON_ONCE(session->leadconn)) return; @@ -986,6 +990,10 @@ static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) iscsi_session_teardown(cls_session); iscsi_host_remove(shost, false); + + tcp_sw_host->session = NULL; + put_device(&cls_session->dev); + iscsi_host_free(shost); }