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
| ||
|
Date: Mon, 2 Aug 2021 20:53:25 -0400 From: Joe Korty <joe.korty@...current-rt.com> To: Zhen Lei <thunder.leizhen@...wei.com> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, stable <stable@...r.kernel.org>, Anna-Maria Gleixner <anna-maria@...utronix.de>, Mike Galbraith <efault@....de>, Sasha Levin <sasha.levin@...cle.com>, Ingo Molnar <mingo@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Thomas Gleixner <tglx@...utronix.de>, linux-kernel <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 4.4 00/11] Fix a potential infinite loop in RT futex-pi scenarios On Mon, Aug 02, 2021 at 09:46:13PM +0800, Zhen Lei wrote: > Commit 73d786bd043e "futex: Rework inconsistent rt_mutex/futex_q state" > mentions that it could cause an infinite loop, and will fix it in the later > patches: > bebe5b514345f09 futex: Futex_unlock_pi() determinism > cfafcd117da0216 futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock() > > But at the moment they're not backported. In a single-core environment, the > probability of triggering is high. > > I also backported commit b4abf91047cf ("rtmutex: Make wait_lock irq safe"), > it fixes a potential deadlock problem. Although it hasn't actually been > triggered in our environment at the moment. > > Other patches are used to resolve conflicts or fix problems caused by new > patches. > > > Anna-Maria Gleixner (1): > rcu: Update documentation of rcu_read_unlock() > > Mike Galbraith (1): > futex: Handle transient "ownerless" rtmutex state correctly > > Peter Zijlstra (6): > futex: Cleanup refcounting > futex,rt_mutex: Introduce rt_mutex_init_waiter() > futex: Pull rt_mutex_futex_unlock() out from under hb->lock > futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock() > futex: Futex_unlock_pi() determinism > futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock() > > Thomas Gleixner (3): > futex: Rename free_pi_state() to put_pi_state() > rtmutex: Make wait_lock irq safe > futex: Avoid freeing an active timer > > include/linux/rcupdate.h | 4 +- > kernel/futex.c | 245 +++++++++++++++++++++----------- > kernel/locking/rtmutex.c | 185 +++++++++++++----------- > kernel/locking/rtmutex_common.h | 2 +- > 4 files changed, 262 insertions(+), 174 deletions(-) To all concerned, I have verified that this series of patches, when applied to 4.4.277, passes the futex-unlock-pi replicator I posted to lkml on July 19. Subject: [BUG] 4.4.262: infinite loop in futex_unlock_pi (EAGAIN loop) Acked-by: Joe Korty <joe.korty@...current-rt.com>
Powered by blists - more mailing lists