From patchwork Tue Apr 12 05:32:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lin Ma X-Patchwork-Id: 12810136 X-Patchwork-Delegate: kuba@kernel.org 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 8E9BAC433F5 for ; Tue, 12 Apr 2022 05:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241050AbiDLFfM (ORCPT ); Tue, 12 Apr 2022 01:35:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229668AbiDLFfL (ORCPT ); Tue, 12 Apr 2022 01:35:11 -0400 Received: from zju.edu.cn (spam.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6A87034B81; Mon, 11 Apr 2022 22:32:53 -0700 (PDT) Received: from localhost.localdomain (unknown [222.205.5.156]) by mail-app3 (Coremail) with SMTP id cC_KCgCn+cn2DlViAenxAQ--.60148S4; Tue, 12 Apr 2022 13:32:39 +0800 (CST) From: Lin Ma To: krzk@kernel.org, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Lin Ma Subject: [PATCH] NFC: NULL out the dev->rfkill to prevent UAF Date: Tue, 12 Apr 2022 13:32:08 +0800 Message-Id: <20220412053208.28681-1-linma@zju.edu.cn> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-CM-TRANSID: cC_KCgCn+cn2DlViAenxAQ--.60148S4 X-Coremail-Antispam: 1UD129KBjvJXoW3AF4UuFy7Kry7ZryDGFWfKrg_yoWxGFW8pr 98KFWfCrWrX34UJw48J3WUGr4rAF4kAF1UJFs7CryUAF4DXF42yryUGrn0qF4UGr1ruFy7 JayDJr12yrZrAw7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUka1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2 z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcV Aq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMxAIw28IcVCjz48v 1sIEY20_GFWkJr1UJwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r 18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr 1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvE x4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUdHUDUUUUU= X-CM-SenderInfo: qtrwiiyqvtljo62m3hxhgxhubq/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Commit 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") assumes the device_is_registered() in function nfc_dev_up() will help to check when the rfkill is unregistered. However, this check only take effect when device_del(&dev->dev) is done in nfc_unregister_device(). Hence, the rfkill object is still possible be dereferenced. The crash trace in latest kernel (5.18-rc2): [ 68.760105] ================================================================== [ 68.760330] BUG: KASAN: use-after-free in __lock_acquire+0x3ec1/0x6750 [ 68.760756] Read of size 8 at addr ffff888009c93018 by task fuzz/313 [ 68.760756] [ 68.760756] CPU: 0 PID: 313 Comm: fuzz Not tainted 5.18.0-rc2 #4 [ 68.760756] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 68.760756] Call Trace: [ 68.760756] [ 68.760756] dump_stack_lvl+0x57/0x7d [ 68.760756] print_report.cold+0x5e/0x5db [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 [ 68.760756] kasan_report+0xbe/0x1c0 [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 [ 68.760756] __lock_acquire+0x3ec1/0x6750 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] ? register_lock_class+0x18d0/0x18d0 [ 68.760756] lock_acquire+0x1ac/0x4f0 [ 68.760756] ? rfkill_blocked+0xe/0x60 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] ? mutex_lock_io_nested+0x12c0/0x12c0 [ 68.760756] ? nla_get_range_signed+0x540/0x540 [ 68.760756] ? _raw_spin_lock_irqsave+0x4e/0x50 [ 68.760756] _raw_spin_lock_irqsave+0x39/0x50 [ 68.760756] ? rfkill_blocked+0xe/0x60 [ 68.760756] rfkill_blocked+0xe/0x60 [ 68.760756] nfc_dev_up+0x84/0x260 [ 68.760756] nfc_genl_dev_up+0x90/0xe0 [ 68.760756] genl_family_rcv_msg_doit+0x1f4/0x2f0 [ 68.760756] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x230/0x230 [ 68.760756] ? security_capable+0x51/0x90 [ 68.760756] genl_rcv_msg+0x280/0x500 [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 [ 68.760756] ? lock_acquire+0x1ac/0x4f0 [ 68.760756] ? nfc_genl_dev_down+0xe0/0xe0 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] netlink_rcv_skb+0x11b/0x340 [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 [ 68.760756] ? netlink_ack+0x9c0/0x9c0 [ 68.760756] ? netlink_deliver_tap+0x136/0xb00 [ 68.760756] genl_rcv+0x1f/0x30 [ 68.760756] netlink_unicast+0x430/0x710 [ 68.760756] ? memset+0x20/0x40 [ 68.760756] ? netlink_attachskb+0x740/0x740 [ 68.760756] ? __build_skb_around+0x1f4/0x2a0 [ 68.760756] netlink_sendmsg+0x75d/0xc00 [ 68.760756] ? netlink_unicast+0x710/0x710 [ 68.760756] ? netlink_unicast+0x710/0x710 [ 68.760756] sock_sendmsg+0xdf/0x110 [ 68.760756] __sys_sendto+0x19e/0x270 [ 68.760756] ? __ia32_sys_getpeername+0xa0/0xa0 [ 68.760756] ? fd_install+0x178/0x4c0 [ 68.760756] ? fd_install+0x195/0x4c0 [ 68.760756] ? kernel_fpu_begin_mask+0x1c0/0x1c0 [ 68.760756] __x64_sys_sendto+0xd8/0x1b0 [ 68.760756] ? lockdep_hardirqs_on+0xbf/0x130 [ 68.760756] ? syscall_enter_from_user_mode+0x1d/0x50 [ 68.760756] do_syscall_64+0x3b/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 68.760756] RIP: 0033:0x7f67fb50e6b3 ... [ 68.760756] RSP: 002b:00007f67fa91fe90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [ 68.760756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67fb50e6b3 [ 68.760756] RDX: 000000000000001c RSI: 0000559354603090 RDI: 0000000000000003 [ 68.760756] RBP: 00007f67fa91ff00 R08: 00007f67fa91fedc R09: 000000000000000c [ 68.760756] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe824d496e [ 68.760756] R13: 00007ffe824d496f R14: 00007f67fa120000 R15: 0000000000000003 [ 68.760756] [ 68.760756] [ 68.760756] Allocated by task 279: [ 68.760756] kasan_save_stack+0x1e/0x40 [ 68.760756] __kasan_kmalloc+0x81/0xa0 [ 68.760756] rfkill_alloc+0x7f/0x280 [ 68.760756] nfc_register_device+0xa3/0x1a0 [ 68.760756] nci_register_device+0x77a/0xad0 [ 68.760756] nfcmrvl_nci_register_dev+0x20b/0x2c0 [ 68.760756] nfcmrvl_nci_uart_open+0xf2/0x1dd [ 68.760756] nci_uart_tty_ioctl+0x2c3/0x4a0 [ 68.760756] tty_ioctl+0x764/0x1310 [ 68.760756] __x64_sys_ioctl+0x122/0x190 [ 68.760756] do_syscall_64+0x3b/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 68.760756] [ 68.760756] Freed by task 314: [ 68.760756] kasan_save_stack+0x1e/0x40 [ 68.760756] kasan_set_track+0x21/0x30 [ 68.760756] kasan_set_free_info+0x20/0x30 [ 68.760756] __kasan_slab_free+0x108/0x170 [ 68.760756] kfree+0xb0/0x330 [ 68.760756] device_release+0x96/0x200 [ 68.760756] kobject_put+0xf9/0x1d0 [ 68.760756] nfc_unregister_device+0x77/0x190 [ 68.760756] nfcmrvl_nci_unregister_dev+0x88/0xd0 [ 68.760756] nci_uart_tty_close+0xdf/0x180 [ 68.760756] tty_ldisc_kill+0x73/0x110 [ 68.760756] tty_ldisc_hangup+0x281/0x5b0 [ 68.760756] __tty_hangup.part.0+0x431/0x890 [ 68.760756] tty_release+0x3a8/0xc80 [ 68.760756] __fput+0x1f0/0x8c0 [ 68.760756] task_work_run+0xc9/0x170 [ 68.760756] exit_to_user_mode_prepare+0x194/0x1a0 [ 68.760756] syscall_exit_to_user_mode+0x19/0x50 [ 68.760756] do_syscall_64+0x48/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae This patch just add the null out of dev->rfkill to make sure such dereference cannot happen. This is safe since the device_lock() already protect the check/write from data race. Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") Signed-off-by: Lin Ma Reviewed-by: Krzysztof Kozlowski --- net/nfc/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/nfc/core.c b/net/nfc/core.c index dc7a2404efdf..67524982b89b 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -1165,6 +1165,7 @@ void nfc_unregister_device(struct nfc_dev *dev) if (dev->rfkill) { rfkill_unregister(dev->rfkill); rfkill_destroy(dev->rfkill); + dev->rfkill = NULL; } device_unlock(&dev->dev);