From patchwork Fri Nov 1 11:44:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Antipov X-Patchwork-Id: 840440 Received: from forward103a.mail.yandex.net (forward103a.mail.yandex.net [178.154.239.86]) (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 2BA3D189B8E for ; Fri, 1 Nov 2024 11:44:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.86 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730461473; cv=none; b=r9XP5NGogTqexJHZu2JKZyqsmG7XJcdB7sbDhqooVBptChGCI3p7E4khFaG8huy+xRaEdoqSj9itaeGLsGOnpDsFcbQVA3aPVXv4721ochkSMI2SXIWAA9Ixzn3nWryzwmfLKUmOeXlon0k9LHKLN+ho+MZfJYSaBssSPVW/HVk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730461473; c=relaxed/simple; bh=xUogVfmXLwTUa7OpjfSpEZAkvy8OaI8tr8JxVlSXGWc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=aRN5irJwL4japMOhUjhAkqepfuJkjJQjIdWwBjCRm11+xVCS2SGUspGIFUTkfyybv3n4U7FmnTvmXITAV/YKFAF/1WIxR38AzhM/doV9qH/+wdOD6GWOLK8i3rwLxSqVsm3YN0b3VKKmSWBCl2JZko9RjUoUCLy57zuaUg4SEb0= 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=gxX37oLd; arc=none smtp.client-ip=178.154.239.86 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="gxX37oLd" Received: from mail-nwsmtp-smtp-production-main-39.vla.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-39.vla.yp-c.yandex.net [IPv6:2a02:6b8:c15:2b05:0:640:2a62:0]) by forward103a.mail.yandex.net (Yandex) with ESMTPS id 5993060AE7; Fri, 1 Nov 2024 14:44:20 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-39.vla.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id JiaN2T3oIeA0-gpyFYpBj; Fri, 01 Nov 2024 14:44:19 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1730461459; bh=nkF8ggMkrvUEAmrNlc1QPCvmTB5ge264BOqD/vMEoJY=; h=Message-ID:Date:Cc:Subject:To:From; b=gxX37oLdu39IyLvu3rHIQEqTKCBP9UrrNWjfMskzYSTc4I3dON3vOFUfSBTHAbLEQ 6GZi3BR+i57Dar1gpLYN1Seb488akKkvoYpzvBIzB/cvJD4M5w6pCwou9BZdguY5vl BcRg657iPFjcY2qhneJMM8r6zs7PcTakX0csDJ9Y= Authentication-Results: mail-nwsmtp-smtp-production-main-39.vla.yp-c.yandex.net; dkim=pass header.i=@yandex.ru From: Dmitry Antipov To: Luiz Augusto von Dentz Cc: Marcel Holtmann , Johan Hedberg , linux-bluetooth@vger.kernel.org, lvc-project@linuxtesting.org, Dmitry Antipov , syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com Subject: [PATCH v2] Bluetooth: fix use-after-free in device_for_each_child() Date: Fri, 1 Nov 2024 14:44:10 +0300 Message-ID: <20241101114410.234311-1-dmantipov@yandex.ru> X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Syzbot has reported the following KASAN splat: BUG: KASAN: slab-use-after-free in device_for_each_child+0x18f/0x1a0 Read of size 8 at addr ffff88801f605308 by task kbnepd bnep0/4980 CPU: 0 UID: 0 PID: 4980 Comm: kbnepd bnep0 Not tainted 6.12.0-rc4-00161-gae90f6a6170d #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 Call Trace: dump_stack_lvl+0x100/0x190 ? device_for_each_child+0x18f/0x1a0 print_report+0x13a/0x4cb ? __virt_addr_valid+0x5e/0x590 ? __phys_addr+0xc6/0x150 ? device_for_each_child+0x18f/0x1a0 kasan_report+0xda/0x110 ? device_for_each_child+0x18f/0x1a0 ? __pfx_dev_memalloc_noio+0x10/0x10 device_for_each_child+0x18f/0x1a0 ? __pfx_device_for_each_child+0x10/0x10 pm_runtime_set_memalloc_noio+0xf2/0x180 netdev_unregister_kobject+0x1ed/0x270 unregister_netdevice_many_notify+0x123c/0x1d80 ? __mutex_trylock_common+0xde/0x250 ? __pfx_unregister_netdevice_many_notify+0x10/0x10 ? trace_contention_end+0xe6/0x140 ? __mutex_lock+0x4e7/0x8f0 ? __pfx_lock_acquire.part.0+0x10/0x10 ? rcu_is_watching+0x12/0xc0 ? unregister_netdev+0x12/0x30 unregister_netdevice_queue+0x30d/0x3f0 ? __pfx_unregister_netdevice_queue+0x10/0x10 ? __pfx_down_write+0x10/0x10 unregister_netdev+0x1c/0x30 bnep_session+0x1fb3/0x2ab0 ? __pfx_bnep_session+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? __pfx_woken_wake_function+0x10/0x10 ? __kthread_parkme+0x132/0x200 ? __pfx_bnep_session+0x10/0x10 ? kthread+0x13a/0x370 ? __pfx_bnep_session+0x10/0x10 kthread+0x2b7/0x370 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x48/0x80 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Allocated by task 4974: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kmalloc_noprof+0x1d1/0x440 hci_alloc_dev_priv+0x1d/0x2820 __vhci_create_device+0xef/0x7d0 vhci_write+0x2c7/0x480 vfs_write+0x6a0/0xfc0 ksys_write+0x12f/0x260 do_syscall_64+0xc7/0x250 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 4979: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x4f/0x70 kfree+0x141/0x490 hci_release_dev+0x4d9/0x600 bt_host_release+0x6a/0xb0 device_release+0xa4/0x240 kobject_put+0x1ec/0x5a0 put_device+0x1f/0x30 vhci_release+0x81/0xf0 __fput+0x3f6/0xb30 task_work_run+0x151/0x250 do_exit+0xa79/0x2c30 do_group_exit+0xd5/0x2a0 get_signal+0x1fcd/0x2210 arch_do_signal_or_restart+0x93/0x780 syscall_exit_to_user_mode+0x140/0x290 do_syscall_64+0xd4/0x250 entry_SYSCALL_64_after_hwframe+0x77/0x7f In 'hci_conn_del_sysfs()', 'device_unregister()' may be called when an underlying (kobject) reference counter is greater than 1. This means that reparenting (happened when the device is actually freed) is delayed and, during that delay, parent controller device (hciX) may be deleted. Since the latter may create a dangling pointer to freed parent, avoid that scenario by reparenting to NULL explicitly. Reported-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f Fixes: a85fb91e3d72 ("Bluetooth: Fix double free in hci_conn_cleanup") Signed-off-by: Dmitry Antipov --- v2: reparent per-connection 'struct device' explicitly --- net/bluetooth/hci_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c index 367e32fe30eb..80ac537fa500 100644 --- a/net/bluetooth/hci_sysfs.c +++ b/net/bluetooth/hci_sysfs.c @@ -73,6 +73,8 @@ void hci_conn_del_sysfs(struct hci_conn *conn) return; } + device_move(&conn->dev, NULL, DPM_ORDER_DEV_LAST); + while (1) { struct device *dev;