From mboxrd@z Thu Jan 1 00:00:00 1970 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 4C2F6C43334 for ; Tue, 7 Jun 2022 21:23:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378296AbiFGVXa (ORCPT ); Tue, 7 Jun 2022 17:23:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379113AbiFGVUC (ORCPT ); Tue, 7 Jun 2022 17:20:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B9FC169DC9; Tue, 7 Jun 2022 11:59:44 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 469EB617A0; Tue, 7 Jun 2022 18:59:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5859EC385A2; Tue, 7 Jun 2022 18:59:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654628382; bh=W6/rJm2x4jEKbutBT4nzL4yNQLM+3X+Q8xBE+50Ah1c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c+0Fi51KFV/dGD1VrGEWbqZk7R1g0ItMthNe3NfbWbP1HOMmY8yZIw/MIJ2ioW1nn RXvzy7gaXmn5qUK2W65Pxn26B4IKts4Sfj6KfvhQ/enw8VCFiOIGx0f3Ktap9NCwyi 1M14d9IluYi4H9bpgyC+Z2PA876oGleUF8vM5IuQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lin Ma , Krzysztof Kozlowski , "David S. Miller" , Sasha Levin Subject: [PATCH 5.18 309/879] NFC: NULL out the dev->rfkill to prevent UAF Date: Tue, 7 Jun 2022 18:57:07 +0200 Message-Id: <20220607165011.816702356@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607165002.659942637@linuxfoundation.org> References: <20220607165002.659942637@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: stable@vger.kernel.org From: Lin Ma [ Upstream commit 1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/nfc/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/nfc/core.c b/net/nfc/core.c index 5b286e1e0a6f..6ff3e10ff8e3 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -1166,6 +1166,7 @@ void nfc_unregister_device(struct nfc_dev *dev) if (dev->rfkill) { rfkill_unregister(dev->rfkill); rfkill_destroy(dev->rfkill); + dev->rfkill = NULL; } dev->shutting_down = true; device_unlock(&dev->dev); -- 2.35.1