linux-kernel - [PATCH v4 0/6] fix hw

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1415030186-18303-1-git-send-email-akong@redhat.com>
Date:	Mon,  3 Nov 2014 23:56:20 +0800
From:	Amos Kong <akong@...hat.com>
To:	virtualization@...ts.linux-foundation.org
Cc:	kvm@...r.kernel.org, rusty@...tcorp.com.au,
	herbert@...dor.apana.org.au, m@...s.ch, mb@...sch.de,
	mpm@...enic.com, amit.shah@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH v4 0/6] fix hw_random stuck

When I hotunplug a busy virtio-rng device or try to access
hwrng attributes in non-smp guest, it gets stuck.

My hotplug tests:

| test 0:
|   hotunplug rng device from qemu monitor
|
| test 1:
|   guest) # dd if=/dev/hwrng of=/dev/null &
|   hotunplug rng device from qemu monitor
|
| test 2:
|   guest) # dd if=/dev/random of=/dev/null &
|   hotunplug rng device from qemu monitor
|
| test 4:
|   guest) # dd if=/dev/hwrng of=/dev/null &
|   cat /sys/devices/virtual/misc/hw_random/rng_*
|
| test 5:
|   guest) # dd if=/dev/hwrng of=/dev/null
|   cancel dd process after 10 seconds
|   guest) # dd if=/dev/hwrng of=/dev/null &
|   hotunplug rng device from qemu monitor
|
| test 6:
|   use a fifo as rng backend, execute test 0 ~ 5 with no input of fifo


V4: update patch 4 to fix corrupt, decrease last reference for triggering
    the cleanup, fix unregister race pointed by Herbert
V3: initialize kref to 1
V2: added patch 2 to fix a deadlock, update current patch 3 to fix reference
    counting issue

Amos Kong (1):
  hw_random: move some code out mutex_lock for avoiding underlying
    deadlock

Rusty Russell (5):
  hw_random: place mutex around read functions and buffers.
  hw_random: use reference counts on each struct hwrng.
  hw_random: fix unregister race.
  hw_random: don't double-check old_rng.
  hw_random: don't init list element we're about to add to list.

 drivers/char/hw_random/core.c | 176 ++++++++++++++++++++++++++++++------------
 include/linux/hw_random.h     |   3 +
 2 files changed, 129 insertions(+), 50 deletions(-)

-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/