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Feras Daoud 0a0007f283 IB/ipoib: Fix deadlock between rmmod and set_mode
When calling set_mode from sys/fs, the call flow locks the sys/fs lock
first and then tries to lock rtnl_lock (when calling ipoib_set_mod).
On the other hand, the rmmod call flow takes the rtnl_lock first
(when calling unregister_netdev) and then tries to take the sys/fs
lock. Deadlock a->b, b->a.

The problem starts when ipoib_set_mod frees it's rtnl_lck and tries
to get it after that.

    set_mod:
    [<ffffffff8104f2bd>] ? check_preempt_curr+0x6d/0x90
    [<ffffffff814fee8e>] __mutex_lock_slowpath+0x13e/0x180
    [<ffffffff81448655>] ? __rtnl_unlock+0x15/0x20
    [<ffffffff814fed2b>] mutex_lock+0x2b/0x50
    [<ffffffff81448675>] rtnl_lock+0x15/0x20
    [<ffffffffa02ad807>] ipoib_set_mode+0x97/0x160 [ib_ipoib]
    [<ffffffffa02b5f5b>] set_mode+0x3b/0x80 [ib_ipoib]
    [<ffffffff8134b840>] dev_attr_store+0x20/0x30
    [<ffffffff811f0fe5>] sysfs_write_file+0xe5/0x170
    [<ffffffff8117b068>] vfs_write+0xb8/0x1a0
    [<ffffffff8117ba81>] sys_write+0x51/0x90
    [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b

    rmmod:
    [<ffffffff81279ffc>] ? put_dec+0x10c/0x110
    [<ffffffff8127a2ee>] ? number+0x2ee/0x320
    [<ffffffff814fe6a5>] schedule_timeout+0x215/0x2e0
    [<ffffffff8127cc04>] ? vsnprintf+0x484/0x5f0
    [<ffffffff8127b550>] ? string+0x40/0x100
    [<ffffffff814fe323>] wait_for_common+0x123/0x180
    [<ffffffff81060250>] ? default_wake_function+0x0/0x20
    [<ffffffff8119661e>] ? ifind_fast+0x5e/0xb0
    [<ffffffff814fe43d>] wait_for_completion+0x1d/0x20
    [<ffffffff811f2e68>] sysfs_addrm_finish+0x228/0x270
    [<ffffffff811f2fb3>] sysfs_remove_dir+0xa3/0xf0
    [<ffffffff81273f66>] kobject_del+0x16/0x40
    [<ffffffff8134cd14>] device_del+0x184/0x1e0
    [<ffffffff8144e59b>] netdev_unregister_kobject+0xab/0xc0
    [<ffffffff8143c05e>] rollback_registered+0xae/0x130
    [<ffffffff8143c102>] unregister_netdevice+0x22/0x70
    [<ffffffff8143c16e>] unregister_netdev+0x1e/0x30
    [<ffffffffa02a91b0>] ipoib_remove_one+0xe0/0x120 [ib_ipoib]
    [<ffffffffa01ed95f>] ib_unregister_device+0x4f/0x100 [ib_core]
    [<ffffffffa021f5e1>] mlx4_ib_remove+0x41/0x180 [mlx4_ib]
    [<ffffffffa01ab771>] mlx4_remove_device+0x71/0x90 [mlx4_core]

Fixes: 862096a8bb ("IB/ipoib: Add more rtnl_link_ops callbacks")
Cc: <stable@vger.kernel.org> # v3.6+
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-01-12 14:01:03 -05:00
arch KVM fixes for v4.10-rc3 2017-01-06 15:27:17 -08:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-01-04 09:03:37 -08:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto crypto: testmgr - Use heap buffer for acomp test input 2016-12-27 17:32:11 +08:00
Documentation VFIO fixes for v4.10-rc3 2017-01-06 11:19:03 -08:00
drivers IB/ipoib: Fix deadlock between rmmod and set_mode 2017-01-12 14:01:03 -05:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit 2017-01-05 23:06:06 -08:00
include RDMA/core: Fix incorrect structure packing for booleans 2017-01-12 12:21:51 -05:00
init mm: add PageWaiters indicating tasks are waiting for a page bit 2016-12-25 11:54:48 -08:00
ipc ipc/sem: avoid idr tree lookup for interrupted semop 2016-12-14 16:04:08 -08:00
kernel Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit 2017-01-05 23:06:06 -08:00
lib mm: workingset: fix use-after-free in shadow node shrinker 2017-01-07 18:22:40 -08:00
mm mm: workingset: fix use-after-free in shadow node shrinker 2017-01-07 18:22:40 -08:00
net drop_monitor: consider inserted data in genlmsg_end 2017-01-03 11:09:44 -05:00
samples vfio-mdev: fix some error codes in the sample code 2017-01-04 08:32:23 -07:00
scripts gcc-plugins: update gcc-common.h for gcc-7 2017-01-03 12:08:59 -08:00
security Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sound Revert "ALSA: firewire-lib: change structure member with proper type" 2017-01-05 08:39:47 +01:00
tools Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2016-12-25 14:01:28 -08:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
COPYING
CREDITS CREDITS: Remove outdated address information 2016-12-21 15:21:29 -08:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS Char/Misc fixes for 4.10-rc3 2017-01-08 11:37:44 -08:00
Makefile Linux 4.10-rc3 2017-01-08 14:18:17 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.