Return-path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:37860 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754817AbeBOHXJ (ORCPT ); Thu, 15 Feb 2018 02:23:09 -0500 Received: by mail-pg0-f65.google.com with SMTP id o1so3592514pgn.4 for ; Wed, 14 Feb 2018 23:23:09 -0800 (PST) From: Sudhir Sreedharan To: herton@canonical.com, htl10@users.sourceforge.net, Larry.Finger@lwfinger.net Cc: kvalo@codeaurora.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Sudhir Sreedharan , stable@vger.kernel.org Subject: [PATCH] rtl8187: Fix NULL pointer dereference in priv->conf_mutex Date: Thu, 15 Feb 2018 12:52:45 +0530 Message-Id: <1518679365-15697-1-git-send-email-ssreedharan@mvista.com> (sfid-20180215_082328_659137_A08A1100) Sender: linux-wireless-owner@vger.kernel.org List-ID: This can be reproduced by bind/unbind the driver multiple times in AM3517 board. Analysis revealed that rtl8187_start() was invoked before probe finishes(ie. before the mutex is initialized). INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 821 Comm: wpa_supplicant Not tainted 4.9.80-dirty #250 Hardware name: Generic AM3517 (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (register_lock_class+0x4f4/0x55c) [] (register_lock_class) from [] (__lock_acquire+0x74/0x1938) [] (__lock_acquire) from [] (lock_acquire+0xfc/0x23c) [] (lock_acquire) from [] (mutex_lock_nested+0x50/0x3b0) [] (mutex_lock_nested) from [] (rtl8187_start+0x2c/0xd54) [] (rtl8187_start) from [] (drv_start+0xa8/0x320) [] (drv_start) from [] (ieee80211_do_open+0x2bc/0x8e4) [] (ieee80211_do_open) from [] (__dev_open+0xb8/0x120) [] (__dev_open) from [] (__dev_change_flags+0x88/0x14c) [] (__dev_change_flags) from [] (dev_change_flags+0x18/0x48) [] (dev_change_flags) from [] (devinet_ioctl+0x738/0x840) [] (devinet_ioctl) from [] (sock_ioctl+0x164/0x2f4) [] (sock_ioctl) from [] (do_vfs_ioctl+0x8c/0x9d0) [] (do_vfs_ioctl) from [] (SyS_ioctl+0x6c/0x7c) [] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x1c) Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = cd1ec000 [00000000] *pgd=8d1de831, *pte=00000000, *ppte=00000000 Internal error: Oops: 817 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 821 Comm: wpa_supplicant Not tainted 4.9.80-dirty #250 Hardware name: Generic AM3517 (Flattened Device Tree) task: ce73eec0 task.stack: cd1ea000 PC is at mutex_lock_nested+0xe8/0x3b0 LR is at mutex_lock_nested+0xd0/0x3b0 Cc: stable@vger.kernel.org Signed-off-by: Sudhir Sreedharan --- drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c index 121b94f..9a1d15b 100644 --- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c +++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c @@ -1450,6 +1450,7 @@ static int rtl8187_probe(struct usb_interface *intf, goto err_free_dev; } mutex_init(&priv->io_mutex); + mutex_init(&priv->conf_mutex); SET_IEEE80211_DEV(dev, &intf->dev); usb_set_intfdata(intf, dev); @@ -1625,7 +1626,6 @@ static int rtl8187_probe(struct usb_interface *intf, printk(KERN_ERR "rtl8187: Cannot register device\n"); goto err_free_dmabuf; } - mutex_init(&priv->conf_mutex); skb_queue_head_init(&priv->b_tx_status.queue); wiphy_info(dev->wiphy, "hwaddr %pM, %s V%d + %s, rfkill mask %d\n", -- 2.6.4