From patchwork Wed Sep 7 23:21:25 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leann Ogasawara X-Patchwork-Id: 113847 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id E1ACFB6F8E for ; Thu, 8 Sep 2011 09:21:50 +1000 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1R1RR6-0008Sg-Tv; Wed, 07 Sep 2011 23:21:40 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1R1RR4-0008Ra-S0 for kernel-team@lists.ubuntu.com; Wed, 07 Sep 2011 23:21:38 +0000 Received: from c-24-21-156-70.hsd1.or.comcast.net ([24.21.156.70] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1R1RR4-0000Qw-C1 for kernel-team@lists.ubuntu.com; Wed, 07 Sep 2011 23:21:38 +0000 From: leann.ogasawara@canonical.com To: kernel-team@lists.ubuntu.com Subject: [PATCH 3/3] rt2x00: fix crash in rt2800usb_write_tx_desc Date: Wed, 7 Sep 2011 16:21:25 -0700 Message-Id: <048792a0b48758bb31daccb265680fa48bb54d1e.1315436708.git.leann.ogasawara@canonical.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: References: In-Reply-To: References: X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com From: Stanislaw Gruszka BugLink: http://bugs.launchpad.net/bugs/842955 Patch should fix this oops: BUG: unable to handle kernel NULL pointer dereference at 000000a0 IP: [] rt2800usb_write_tx_desc+0x18/0xc0 [rt2800usb] *pdpt = 000000002408c001 *pde = 0000000024079067 *pte = 0000000000000000 Oops: 0000 [#1] SMP EIP: 0060:[] EFLAGS: 00010282 CPU: 0 EIP is at rt2800usb_write_tx_desc+0x18/0xc0 [rt2800usb] EAX: 00000035 EBX: ef2bef10 ECX: 00000000 EDX: d40958a0 ESI: ef1865f8 EDI: ef1865f8 EBP: d4095878 ESP: d409585c DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Call Trace: [] rt2x00queue_write_tx_frame+0x155/0x300 [rt2x00lib] [] rt2x00mac_tx+0x7c/0x370 [rt2x00lib] [] ? mark_held_locks+0x62/0x90 [] ? _raw_spin_unlock_irqrestore+0x35/0x60 [] ? trace_hardirqs_on_caller+0x5a/0x170 [] ? trace_hardirqs_on+0xb/0x10 [] __ieee80211_tx+0x5c/0x1e0 [mac80211] [] ieee80211_tx+0xbc/0xe0 [mac80211] [] ? ieee80211_tx+0x23/0xe0 [mac80211] [] ieee80211_xmit+0xc1/0x200 [mac80211] [] ? ieee80211_tx+0xe0/0xe0 [mac80211] [] ? lock_release_holdtime+0x35/0x1b0 [] ? ieee80211_subif_start_xmit+0x446/0x5f0 [mac80211] [] ieee80211_subif_start_xmit+0x29d/0x5f0 [mac80211] [] ? ieee80211_subif_start_xmit+0x3e4/0x5f0 [mac80211] [] ? sock_setsockopt+0x6a8/0x6f0 [] ? sock_setsockopt+0x520/0x6f0 [] dev_hard_start_xmit+0x2ef/0x650 Oops might happen because we perform parallel putting new entries in a queue (rt2x00queue_write_tx_frame()) and removing entries after finishing transmitting (rt2800usb_work_txdone()). There are cases when _txdone may process an entry that was not fully send and nullify entry->skb . To fix check in _txdone if entry has flags that indicate pending transmission and wait until flags get cleared. Reported-by: Justin Piszcz Cc: stable@kernel.org Signed-off-by: Stanislaw Gruszka Acked-by: Ivo van Doorn Signed-off-by: John W. Linville (cherry picked from commit 4b1bfb7d2d125af6653d6c2305356b2677f79dc6) Signed-off-by: Leann Ogasawara --- drivers/net/wireless/rt2x00/rt2800usb.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c index 4ad663a..80fb51e 100644 --- a/drivers/net/wireless/rt2x00/rt2800usb.c +++ b/drivers/net/wireless/rt2x00/rt2800usb.c @@ -464,6 +464,15 @@ static bool rt2800usb_txdone_entry_check(struct queue_entry *entry, u32 reg) int wcid, ack, pid; int tx_wcid, tx_ack, tx_pid; + if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) || + !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags)) { + WARNING(entry->queue->rt2x00dev, + "Data pending for entry %u in queue %u\n", + entry->entry_idx, entry->queue->qid); + cond_resched(); + return false; + } + wcid = rt2x00_get_field32(reg, TX_STA_FIFO_WCID); ack = rt2x00_get_field32(reg, TX_STA_FIFO_TX_ACK_REQUIRED); pid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_TYPE); @@ -557,8 +566,10 @@ static void rt2800usb_work_txdone(struct work_struct *work) while (!rt2x00queue_empty(queue)) { entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE); - if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) + if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) || + !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags)) break; + if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags)) rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE); else if (rt2x00queue_status_timeout(entry))