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Shuah Khan 0c9e8b3cad usbip: usbip_host: fix BUG: sleeping function called from invalid context
stub_probe() and stub_disconnect() call functions which could call
sleeping function in invalid context whil holding busid_lock.

Fix the problem by refining the lock holds to short critical sections
to change the busid_priv fields. This fix restructures the code to
limit the lock holds in stub_probe() and stub_disconnect().

stub_probe():

[15217.927028] BUG: sleeping function called from invalid context at mm/slab.h:418
[15217.927038] in_atomic(): 1, irqs_disabled(): 0, pid: 29087, name: usbip
[15217.927044] 5 locks held by usbip/29087:
[15217.927047]  #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0
[15217.927062]  #1: 000000008f9ba75b (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0
[15217.927072]  #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50
[15217.927082]  #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50
[15217.927090]  #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host]
[15217.927103] CPU: 3 PID: 29087 Comm: usbip Tainted: G        W         5.1.0-rc6+ #40
[15217.927106] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013
[15217.927109] Call Trace:
[15217.927118]  dump_stack+0x63/0x85
[15217.927127]  ___might_sleep+0xff/0x120
[15217.927133]  __might_sleep+0x4a/0x80
[15217.927143]  kmem_cache_alloc_trace+0x1aa/0x210
[15217.927156]  stub_probe+0xe8/0x440 [usbip_host]
[15217.927171]  usb_probe_device+0x34/0x70

stub_disconnect():

[15279.182478] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
[15279.182487] in_atomic(): 1, irqs_disabled(): 0, pid: 29114, name: usbip
[15279.182492] 5 locks held by usbip/29114:
[15279.182494]  #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0
[15279.182506]  #1: 00000000702cf0f3 (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0
[15279.182514]  #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50
[15279.182522]  #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50
[15279.182529]  #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host]
[15279.182541] CPU: 0 PID: 29114 Comm: usbip Tainted: G        W         5.1.0-rc6+ #40
[15279.182543] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013
[15279.182546] Call Trace:
[15279.182554]  dump_stack+0x63/0x85
[15279.182561]  ___might_sleep+0xff/0x120
[15279.182566]  __might_sleep+0x4a/0x80
[15279.182574]  __mutex_lock+0x55/0x950
[15279.182582]  ? get_busid_priv+0x48/0x60 [usbip_host]
[15279.182587]  ? reacquire_held_locks+0xec/0x1a0
[15279.182591]  ? get_busid_priv+0x48/0x60 [usbip_host]
[15279.182597]  ? find_held_lock+0x94/0xa0
[15279.182609]  mutex_lock_nested+0x1b/0x20
[15279.182614]  ? mutex_lock_nested+0x1b/0x20
[15279.182618]  kernfs_remove_by_name_ns+0x2a/0x90
[15279.182625]  sysfs_remove_file_ns+0x15/0x20
[15279.182629]  device_remove_file+0x19/0x20
[15279.182634]  stub_disconnect+0x6d/0x180 [usbip_host]
[15279.182643]  usb_unbind_device+0x27/0x60

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:08:56 +02:00
Documentation Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
block for-5.2/block-post-20190516 2019-05-16 19:08:15 -07:00
certs kexec, KEYS: Make use of platform keyring for signature verify 2019-02-04 17:34:07 -05:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-05-07 22:03:58 -07:00
drivers usbip: usbip_host: fix BUG: sleeping function called from invalid context 2019-05-21 10:08:56 +02:00
fs This pull request contains the following fixes for UBIFS: 2019-05-19 15:22:03 -07:00
include Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
init initramfs: don't free a non-existent initrd 2019-05-18 15:52:26 -07:00
ipc ipc: do cyclic id allocation for the ipc object. 2019-05-14 19:52:52 -07:00
kernel Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
lib slab: remove /proc/slab_allocators 2019-05-16 15:51:55 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
net treewide: prefix header search paths with $(srctree)/ 2019-05-18 11:49:57 +09:00
samples samples: guard sub-directories with CONFIG options 2019-05-18 11:29:01 +09:00
scripts kconfig: use 'else ifneq' for Makefile to improve readability 2019-05-19 09:34:35 +09:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-13 15:15:00 -07:00
sound sound fixes for 5.2-rc1 2019-05-17 13:57:54 -07:00
tools Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-19 11:20:22 -07:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt * ARM: support for SVE and Pointer Authentication in guests, PMU improvements 2019-05-17 10:33:30 -07:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: exclude .get_maintainer.ignore and .gitattributes 2019-05-18 11:49:54 +09:00
.mailmap A reasonably busy cycle for docs, including: 2019-05-08 12:42:50 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Kbuild updates for v5.2 (2nd) 2019-05-19 11:53:58 -07:00
Makefile Linux 5.2-rc1 2019-05-19 15:47:09 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.