linux/drivers/usb
Bjørn Mork a1028f0abf usb: usb_wwan: replace release and disconnect with a port_remove hook
Doing port specific cleanup in the .port_remove hook is a
lot simpler and safer than doing it in the USB driver
.release or .disconnect methods. The removal of the port
from the usb-serial bus will happen before the USB driver
cleanup, so we must be careful about accessing port specific
driver data from any USB driver functions.

This problem surfaced after the commit

 0998d0631 device-core: Ensure drvdata = NULL when no driver is bound

which turned the previous unsafe access into a reliable NULL
pointer dereference.

Fixes the following Oops:

[  243.148471] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  243.148508] IP: [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[  243.148556] PGD 79d60067 PUD 79d61067 PMD 0
[  243.148590] Oops: 0000 [#1] SMP
[  243.148617] Modules linked in: sr_mod cdrom qmi_wwan usbnet option cdc_wdm usb_wwan usbserial usb_storage uas fuse af_packet ip6table_filter ip6_tables iptable_filter ip_tables x_tables tun edd
cpufreq_conservative cpufreq_userspace cpufreq_powersave snd_pcm_oss snd_mixer_oss acpi_cpufreq snd_seq mperf snd_seq_device coretemp arc4 sg hp_wmi sparse_keymap uvcvideo videobuf2_core
videodev videobuf2_vmalloc videobuf2_memops rtl8192ce rtl8192c_common rtlwifi joydev pcspkr microcode mac80211 i2c_i801 lpc_ich r8169 snd_hda_codec_idt cfg80211 snd_hda_intel snd_hda_codec rfkill
snd_hwdep snd_pcm wmi snd_timer ac snd soundcore snd_page_alloc battery uhci_hcd i915 drm_kms_helper drm i2c_algo_bit ehci_hcd thermal usbcore video usb_common button processor thermal_sys
[  243.149007] CPU 1
[  243.149027] Pid: 135, comm: khubd Not tainted 3.5.0-rc7-next-20120720-1-vanilla #1 Hewlett-Packard HP Mini 110-3700                /1584
[  243.149072] RIP: 0010:[<ffffffffa0468527>]  [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[  243.149118] RSP: 0018:ffff880037e75b30  EFLAGS: 00010286
[  243.149133] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88005912aa28
[  243.149150] RDX: ffff88005e95f028 RSI: 0000000000000000 RDI: ffff88005f7c1a10
[  243.149166] RBP: ffff880037e75b60 R08: 0000000000000000 R09: ffffffff812cea90
[  243.149182] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88006539b440
[  243.149198] R13: ffff88006539b440 R14: 0000000000000000 R15: 0000000000000000
[  243.149216] FS:  0000000000000000(0000) GS:ffff88007ee80000(0000) knlGS:0000000000000000
[  243.149233] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  243.149248] CR2: 0000000000000000 CR3: 0000000079fe0000 CR4: 00000000000007e0
[  243.149264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  243.149280] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  243.149298] Process khubd (pid: 135, threadinfo ffff880037e74000, task ffff880037d40600)
[  243.149313] Stack:
[  243.149323]  ffff880037e75b40 ffff88006539b440 ffff8800799bc830 ffff88005f7c1800
[  243.149348]  0000000000000001 ffff88006539b448 ffff880037e75b70 ffffffffa04685e9
[  243.149371]  ffff880037e75bc0 ffffffffa0473765 ffff880037354988 ffff88007b594800
[  243.149395] Call Trace:
[  243.149419]  [<ffffffffa04685e9>] usb_wwan_disconnect+0x9/0x10 [usb_wwan]
[  243.149447]  [<ffffffffa0473765>] usb_serial_disconnect+0xd5/0x120 [usbserial]
[  243.149511]  [<ffffffffa0046b48>] usb_unbind_interface+0x58/0x1a0 [usbcore]
[  243.149545]  [<ffffffff8139ebd7>] __device_release_driver+0x77/0xe0
[  243.149567]  [<ffffffff8139ec67>] device_release_driver+0x27/0x40
[  243.149587]  [<ffffffff8139e5cf>] bus_remove_device+0xdf/0x150
[  243.149608]  [<ffffffff8139bc78>] device_del+0x118/0x1a0
[  243.149661]  [<ffffffffa0044590>] usb_disable_device+0xb0/0x280 [usbcore]
[  243.149718]  [<ffffffffa003c6fd>] usb_disconnect+0x9d/0x140 [usbcore]
[  243.149770]  [<ffffffffa003da7d>] hub_port_connect_change+0xad/0x8a0 [usbcore]
[  243.149825]  [<ffffffffa0043bf5>] ? usb_control_msg+0xe5/0x110 [usbcore]
[  243.149878]  [<ffffffffa003e6e3>] hub_events+0x473/0x760 [usbcore]
[  243.149931]  [<ffffffffa003ea05>] hub_thread+0x35/0x1d0 [usbcore]
[  243.149955]  [<ffffffff81061960>] ? add_wait_queue+0x60/0x60
[  243.150004]  [<ffffffffa003e9d0>] ? hub_events+0x760/0x760 [usbcore]
[  243.150026]  [<ffffffff8106133e>] kthread+0x8e/0xa0
[  243.150047]  [<ffffffff8157ec04>] kernel_thread_helper+0x4/0x10
[  243.150068]  [<ffffffff810612b0>] ? flush_kthread_work+0x120/0x120
[  243.150088]  [<ffffffff8157ec00>] ? gs_change+0xb/0xb
[  243.150101] Code: fd 41 54 53 48 83 ec 08 80 7f 1a 00 74 57 49 89 fc 31 db 90 49 8b 7c 24 20 45 31 f6 48 81 c7 10 02 00 00 e8 bc 64 f3 e0 49 89 c7 <4b> 8b 3c 37 49 83 c6 08 e8 4c a5 bd ff 49 83 fe 20
75 ed 45 30
[  243.150257] RIP  [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[  243.150282]  RSP <ffff880037e75b30>
[  243.150294] CR2: 0000000000000000
[  243.177170] ---[ end trace fba433d9015ffb8c ]---

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Thomas Schäfer <tschaefer@t-online.de>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-10 11:51:43 -07:00
..
atm usb: Use eth_random_addr 2012-07-16 22:39:07 -07:00
c67x00 usb: convert drivers/usb/* to use module_platform_driver() 2011-11-28 06:48:32 +09:00
chipidea usb: chipidea: fix and improve dependencies if usb host or gadget support is built as module 2012-08-10 11:46:04 -07:00
class Merge 3.5-rc7 into usb-next 2012-07-16 13:16:09 -07:00
core This patch series contains a major revamp of how we collect entropy 2012-07-31 19:07:42 -07:00
dwc3 usb: dwc3: patches for v3.6 merge window 2012-07-05 15:15:38 -07:00
early usb: early: fixed coding style issue related to : operator 2012-06-13 16:07:22 -07:00
gadget Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
host USB: isp1362-hcd.c: usb message always saved in case of underrun 2012-08-10 11:49:13 -07:00
image USB: mdc800.c: remove dbg() usage 2012-05-01 21:33:50 -07:00
misc USB: yurex.c: remove dbg() usage 2012-05-01 21:34:11 -07:00
mon usb: Add export.h for EXPORT_SYMBOL/THIS_MODULE where needed 2011-10-31 19:31:25 -04:00
musb usb: musb: reorder runtime pm call 2012-08-03 09:30:44 +03:00
otg This patch series contains a major revamp of how we collect entropy 2012-07-31 19:07:42 -07:00
phy usb: phy: Fix Kconfig dependency for Phy drivers 2012-06-26 16:14:33 -07:00
renesas_usbhs USB patches for 3.6-rc1 2012-07-26 10:23:47 -07:00
serial usb: usb_wwan: replace release and disconnect with a port_remove hook 2012-08-10 11:51:43 -07:00
storage [SCSI] usb-storage: update usb devices for write cache quirk in quirk list. 2012-07-20 08:59:00 +01:00
wusbcore uwb & wusb: fix kconfig error 2012-01-26 11:22:42 -08:00
Kconfig usb: move ci13xxx and related code to drivers/usb/chipidea 2012-05-11 16:45:30 -07:00
Makefile usb: phy: Fix Kconfig dependency for Phy drivers 2012-06-26 16:14:33 -07:00
README
usb-common.c usb: Provide usb_speed_string() function 2011-09-18 01:29:04 -07:00
usb-skeleton.c USB: usb-skeleton.c: remove err() usage 2012-04-27 11:24:45 -07:00

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("khubd").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
../input/	- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
../media/	- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
../net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.