Return-path: Received: from mail-wi0-f172.google.com ([209.85.212.172]:40810 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752817AbaGETJd (ORCPT ); Sat, 5 Jul 2014 15:09:33 -0400 Received: by mail-wi0-f172.google.com with SMTP id hi2so14100274wib.11 for ; Sat, 05 Jul 2014 12:09:31 -0700 (PDT) From: Andrea Merello To: helmut.schaa@googlemail.com, IvDoorn@gmail.com, linville@tuxdriver.com Cc: users@rt2x00.serialmonkey.com, linux-wireless@vger.kernel.org, nbd@openwrt.org, mattias.nissler@gmx.de, xose.vazquez@gmail.com, rain_maker@root-forum.org, Andrea Merello Subject: [PATCH] rt2800usb: Don't perform DMA from stack Date: Sat, 5 Jul 2014 21:07:17 +0200 Message-Id: <1404587237-26187-1-git-send-email-andrea.merello@gmail.com> (sfid-20140705_210937_390975_AF2EE394) Sender: linux-wireless-owner@vger.kernel.org List-ID: Function rt2800usb_autorun_detect() passes the address of a variable allocated onto the stack to be used for DMA by the USB layer. This has been caught by my debugging-enabled kernel. This patch change things in order to allocate that variable via kmalloc, and it adjusts things to handle the kmalloc failure case, propagating the error. [ 7363.238852] ------------[ cut here ]------------ [ 7363.243529] WARNING: CPU: 1 PID: 5235 at lib/dma-debug.c:1153 check_for_stack+0xa4/0xf0() [ 7363.251759] ehci-pci 0000:00:04.1: DMA-API: device driver maps memory fromstack [addr=ffff88006b81bad4] [ 7363.261210] Modules linked in: rt2800usb(O+) rt2800lib(O) rt2x00usb(O) rt2x00lib(O) rtl818x_pci(O) rtl8187 led_class eeprom_93cx6 mac80211 cfg80211 [last unloaded: rt2x00lib] [ 7363.277143] CPU: 1 PID: 5235 Comm: systemd-udevd Tainted: G O 3.16.0-rc3-wl+ #31 [ 7363.285546] Hardware name: System manufacturer System Product Name/M3N78 PRO, BIOS ASUS M3N78 PRO ACPI BIOS Revision 1402 12/04/2009 [ 7363.297511] 0000000000000009 ffff88006b81b710 ffffffff8175dcad ffff88006b81b758 [ 7363.305062] ffff88006b81b748 ffffffff8106d372 ffff88006cf10098 ffff88006cead6a0 [ 7363.312622] ffff88006b81bad4 ffffffff81c1e7c0 ffff88006cf10098 ffff88006b81b7a8 [ 7363.320161] Call Trace: [ 7363.322661] [] dump_stack+0x4d/0x6f [ 7363.327847] [] warn_slowpath_common+0x82/0xb0 [ 7363.333893] [] warn_slowpath_fmt+0x47/0x50 [ 7363.339686] [] check_for_stack+0xa4/0xf0 [ 7363.345298] [] debug_dma_map_page+0x10c/0x150 [ 7363.351367] [] usb_hcd_map_urb_for_dma+0x229/0x720 [ 7363.357890] [] usb_hcd_submit_urb+0x2fd/0x930 [ 7363.363929] [] ? irq_work_queue+0x71/0xd0 [ 7363.369617] [] ? wake_up_klogd+0x37/0x50 [ 7363.375219] [] ? console_unlock+0x1e5/0x420 [ 7363.381081] [] ? vprintk_emit+0x245/0x530 [ 7363.386773] [] usb_submit_urb+0x30c/0x580 [ 7363.392462] [] usb_start_wait_urb+0x65/0xf0 [ 7363.398325] [] usb_control_msg+0xcd/0x110 [ 7363.404014] [] rt2x00usb_vendor_request+0xbd/0x170 [rt2x00usb] [ 7363.411544] [] rt2800usb_autorun_detect+0x32/0x50 [rt2800usb] [ 7363.418986] [] rt2800usb_read_eeprom+0x11/0x70 [rt2800usb] [ 7363.426168] [] rt2800_probe_hw+0x11d/0xf90 [rt2800lib] [ 7363.432989] [] rt2800usb_probe_hw+0xd/0x50 [rt2800usb] [ 7363.439808] [] rt2x00lib_probe_dev+0x238/0x7c0 [rt2x00lib] [ 7363.446992] [] ? ieee80211_led_names+0xb8/0x100 [mac80211] [ 7363.454156] [] rt2x00usb_probe+0x156/0x1f0 [rt2x00usb] [ 7363.460971] [] rt2800usb_probe+0x10/0x20 [rt2800usb] [ 7363.467616] [] usb_probe_interface+0xce/0x1c0 [ 7363.473651] [] really_probe+0x70/0x240 [ 7363.479079] [] __driver_attach+0xa1/0xb0 [ 7363.484682] [] ? __device_attach+0x70/0x70 [ 7363.490461] [] bus_for_each_dev+0x63/0xa0 [ 7363.496146] [] driver_attach+0x19/0x20 [ 7363.501570] [] bus_add_driver+0x178/0x220 [ 7363.507270] [] driver_register+0x5b/0xe0 [ 7363.512874] [] usb_register_driver+0xa0/0x170 [ 7363.518905] [] ? 0xffffffffa0079fff [ 7363.524074] [] rt2800usb_driver_init+0x1e/0x20 [rt2800usb] [ 7363.531247] [] do_one_initcall+0x84/0x1b0 [ 7363.536932] [] ? kfree+0xd0/0x110 [ 7363.541931] [] ? __vunmap+0xaa/0xf0 [ 7363.547538] [] load_module+0x1aee/0x2040 [ 7363.553141] [] ? store_uevent+0x50/0x50 [ 7363.558676] [] SyS_init_module+0x9e/0xc0 [ 7363.564285] [] system_call_fastpath+0x16/0x1b [ 7363.570338] ---[ end trace 01ef5f822bea9882 ]--- Signed-off-by: Andrea Merello --- drivers/net/wireless/rt2x00/rt2800usb.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c index e11dab2..832006b 100644 --- a/drivers/net/wireless/rt2x00/rt2800usb.c +++ b/drivers/net/wireless/rt2x00/rt2800usb.c @@ -231,9 +231,12 @@ static enum hrtimer_restart rt2800usb_tx_sta_fifo_timeout(struct hrtimer *timer) */ static int rt2800usb_autorun_detect(struct rt2x00_dev *rt2x00dev) { - __le32 reg; + __le32 *reg; u32 fw_mode; + reg = kmalloc(sizeof(*reg), GFP_KERNEL); + if (reg == NULL) + return -ENOMEM; /* cannot use rt2x00usb_register_read here as it uses different * mode (MULTI_READ vs. DEVICE_MODE) and does not pass the * magic value USB_MODE_AUTORUN (0x11) to the device, thus the @@ -241,8 +244,9 @@ static int rt2800usb_autorun_detect(struct rt2x00_dev *rt2x00dev) */ rt2x00usb_vendor_request(rt2x00dev, USB_DEVICE_MODE, USB_VENDOR_REQUEST_IN, 0, USB_MODE_AUTORUN, - ®, sizeof(reg), REGISTER_TIMEOUT_FIRMWARE); - fw_mode = le32_to_cpu(reg); + reg, sizeof(*reg), REGISTER_TIMEOUT_FIRMWARE); + fw_mode = le32_to_cpu(*reg); + kfree(reg); if ((fw_mode & 0x00000003) == 2) return 1; @@ -261,6 +265,7 @@ static int rt2800usb_write_firmware(struct rt2x00_dev *rt2x00dev, int status; u32 offset; u32 length; + int retval; /* * Check which section of the firmware we need. @@ -278,7 +283,10 @@ static int rt2800usb_write_firmware(struct rt2x00_dev *rt2x00dev, /* * Write firmware to device. */ - if (rt2800usb_autorun_detect(rt2x00dev)) { + retval = rt2800usb_autorun_detect(rt2x00dev); + if (retval < 0) + return retval; + if (retval) { rt2x00_info(rt2x00dev, "Firmware loading not required - NIC in AutoRun mode\n"); } else { @@ -763,7 +771,12 @@ static void rt2800usb_fill_rxdone(struct queue_entry *entry, */ static int rt2800usb_efuse_detect(struct rt2x00_dev *rt2x00dev) { - if (rt2800usb_autorun_detect(rt2x00dev)) + int retval; + + retval = rt2800usb_autorun_detect(rt2x00dev); + if (retval < 0) + return retval; + if (retval) return 1; return rt2800_efuse_detect(rt2x00dev); } @@ -772,7 +785,10 @@ static int rt2800usb_read_eeprom(struct rt2x00_dev *rt2x00dev) { int retval; - if (rt2800usb_efuse_detect(rt2x00dev)) + retval = rt2800usb_efuse_detect(rt2x00dev); + if (retval < 0) + return retval; + if (retval) retval = rt2800_read_eeprom_efuse(rt2x00dev); else retval = rt2x00usb_eeprom_read(rt2x00dev, rt2x00dev->eeprom, -- 1.9.1