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 4C707C433FE for ; Mon, 27 Dec 2021 15:39:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238658AbhL0Pi7 (ORCPT ); Mon, 27 Dec 2021 10:38:59 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:40900 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238535AbhL0PhN (ORCPT ); Mon, 27 Dec 2021 10:37:13 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 5738BCE10D2; Mon, 27 Dec 2021 15:37:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16383C36AEA; Mon, 27 Dec 2021 15:37:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640619429; bh=4KCna9C8mC+FvcbcT1kttdc2NS9gKQ4mSk4IfMo2J2k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=umiwvConyhX1YygUbr5AUUkP5pLOZPexJxY47ZqZ1LKxRpzpB1TmQCrU8+JlqIU4z welcpUx3z2nDw95ONubCFOh32QQv/fzELN5HciREZW75EeiMDQU7sGPfWwvYP2UJMc sRxzPIVwdIWYISl4ViWPT5gAwbcfGRsK6t9T+Gu0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wu Bo , Corey Minyard , Sasha Levin Subject: [PATCH 5.10 21/76] ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module Date: Mon, 27 Dec 2021 16:30:36 +0100 Message-Id: <20211227151325.419125615@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211227151324.694661623@linuxfoundation.org> References: <20211227151324.694661623@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wu Bo [ Upstream commit ffb76a86f8096a8206be03b14adda6092e18e275 ] Hi, When testing install and uninstall of ipmi_si.ko and ipmi_msghandler.ko, the system crashed. The log as follows: [ 141.087026] BUG: unable to handle kernel paging request at ffffffffc09b3a5a [ 141.087241] PGD 8fe4c0d067 P4D 8fe4c0d067 PUD 8fe4c0f067 PMD 103ad89067 PTE 0 [ 141.087464] Oops: 0010 [#1] SMP NOPTI [ 141.087580] CPU: 67 PID: 668 Comm: kworker/67:1 Kdump: loaded Not tainted 4.18.0.x86_64 #47 [ 141.088009] Workqueue: events 0xffffffffc09b3a40 [ 141.088009] RIP: 0010:0xffffffffc09b3a5a [ 141.088009] Code: Bad RIP value. [ 141.088009] RSP: 0018:ffffb9094e2c3e88 EFLAGS: 00010246 [ 141.088009] RAX: 0000000000000000 RBX: ffff9abfdb1f04a0 RCX: 0000000000000000 [ 141.088009] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 141.088009] RBP: 0000000000000000 R08: ffff9abfffee3cb8 R09: 00000000000002e1 [ 141.088009] R10: ffffb9094cb73d90 R11: 00000000000f4240 R12: ffff9abfffee8700 [ 141.088009] R13: 0000000000000000 R14: ffff9abfdb1f04a0 R15: ffff9abfdb1f04a8 [ 141.088009] FS: 0000000000000000(0000) GS:ffff9abfffec0000(0000) knlGS:0000000000000000 [ 141.088009] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 141.088009] CR2: ffffffffc09b3a30 CR3: 0000008fe4c0a001 CR4: 00000000007606e0 [ 141.088009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 141.088009] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 141.088009] PKRU: 55555554 [ 141.088009] Call Trace: [ 141.088009] ? process_one_work+0x195/0x390 [ 141.088009] ? worker_thread+0x30/0x390 [ 141.088009] ? process_one_work+0x390/0x390 [ 141.088009] ? kthread+0x10d/0x130 [ 141.088009] ? kthread_flush_work_fn+0x10/0x10 [ 141.088009] ? ret_from_fork+0x35/0x40] BUG: unable to handle kernel paging request at ffffffffc0b28a5a [ 200.223240] PGD 97fe00d067 P4D 97fe00d067 PUD 97fe00f067 PMD a580cbf067 PTE 0 [ 200.223464] Oops: 0010 [#1] SMP NOPTI [ 200.223579] CPU: 63 PID: 664 Comm: kworker/63:1 Kdump: loaded Not tainted 4.18.0.x86_64 #46 [ 200.224008] Workqueue: events 0xffffffffc0b28a40 [ 200.224008] RIP: 0010:0xffffffffc0b28a5a [ 200.224008] Code: Bad RIP value. [ 200.224008] RSP: 0018:ffffbf3c8e2a3e88 EFLAGS: 00010246 [ 200.224008] RAX: 0000000000000000 RBX: ffffa0799ad6bca0 RCX: 0000000000000000 [ 200.224008] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 200.224008] RBP: 0000000000000000 R08: ffff9fe43fde3cb8 R09: 00000000000000d5 [ 200.224008] R10: ffffbf3c8cb53d90 R11: 00000000000f4240 R12: ffff9fe43fde8700 [ 200.224008] R13: 0000000000000000 R14: ffffa0799ad6bca0 R15: ffffa0799ad6bca8 [ 200.224008] FS: 0000000000000000(0000) GS:ffff9fe43fdc0000(0000) knlGS:0000000000000000 [ 200.224008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 200.224008] CR2: ffffffffc0b28a30 CR3: 00000097fe00a002 CR4: 00000000007606e0 [ 200.224008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 200.224008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 200.224008] PKRU: 55555554 [ 200.224008] Call Trace: [ 200.224008] ? process_one_work+0x195/0x390 [ 200.224008] ? worker_thread+0x30/0x390 [ 200.224008] ? process_one_work+0x390/0x390 [ 200.224008] ? kthread+0x10d/0x130 [ 200.224008] ? kthread_flush_work_fn+0x10/0x10 [ 200.224008] ? ret_from_fork+0x35/0x40 [ 200.224008] kernel fault(0x1) notification starting on CPU 63 [ 200.224008] kernel fault(0x1) notification finished on CPU 63 [ 200.224008] CR2: ffffffffc0b28a5a [ 200.224008] ---[ end trace c82a412d93f57412 ]--- The reason is as follows: T1: rmmod ipmi_si. ->ipmi_unregister_smi() -> ipmi_bmc_unregister() -> __ipmi_bmc_unregister() -> kref_put(&bmc->usecount, cleanup_bmc_device); -> schedule_work(&bmc->remove_work); T2: rmmod ipmi_msghandler. ipmi_msghander module uninstalled, and the module space will be freed. T3: bmc->remove_work doing cleanup the bmc resource. -> cleanup_bmc_work() -> platform_device_unregister(&bmc->pdev); -> platform_device_del(pdev); -> device_del(&pdev->dev); -> kobject_uevent(&dev->kobj, KOBJ_REMOVE); -> kobject_uevent_env() -> dev_uevent() -> if (dev->type && dev->type->name) 'dev->type'(bmc_device_type) pointer space has freed when uninstall ipmi_msghander module, 'dev->type->name' cause the system crash. drivers/char/ipmi/ipmi_msghandler.c: 2820 static const struct device_type bmc_device_type = { 2821 .groups = bmc_dev_attr_groups, 2822 }; Steps to reproduce: Add a time delay in cleanup_bmc_work() function, and uninstall ipmi_si and ipmi_msghandler module. 2910 static void cleanup_bmc_work(struct work_struct *work) 2911 { 2912 struct bmc_device *bmc = container_of(work, struct bmc_device, 2913 remove_work); 2914 int id = bmc->pdev.id; /* Unregister overwrites id */ 2915 2916 msleep(3000); <--- 2917 platform_device_unregister(&bmc->pdev); 2918 ida_simple_remove(&ipmi_bmc_ida, id); 2919 } Use 'remove_work_wq' instead of 'system_wq' to solve this issues. Fixes: b2cfd8ab4add ("ipmi: Rework device id and guid handling to catch changing BMCs") Signed-off-by: Wu Bo Message-Id: <1640070034-56671-1-git-send-email-wubo40@huawei.com> Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin --- drivers/char/ipmi/ipmi_msghandler.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 38b545bef05a3..fc6445ed7c377 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -2945,7 +2945,7 @@ cleanup_bmc_device(struct kref *ref) * with removing the device attributes while reading a device * attribute. */ - schedule_work(&bmc->remove_work); + queue_work(remove_work_wq, &bmc->remove_work); } /* -- 2.34.1