linux-kernel - Re: [BUG] usbip: vhci: Sleeping function called from invalid context in vhci_urb_enqueue on PREEMPT

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-prev] [day] [month] [year] [list]

Message-ID: <2bf33071-e05e-4b89-b149-30b90888606f@rowland.harvard.edu>
Date: Sun, 17 Aug 2025 10:27:11 -0400
From: Alan Stern <stern@...land.harvard.edu>
To: Yunseong Kim <ysk@...lloc.com>
Cc: linux-usb@...r.kernel.org, gregkh@...uxfoundation.org,
	Andrey Konovalov <andreyknvl@...gle.com>,
	Shuah Khan <skhan@...uxfoundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	Clark Williams <clrkwllms@...nel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org,
	syzkaller@...glegroups.com
Subject: Re: [BUG] usbip: vhci: Sleeping function called from invalid context
 in vhci_urb_enqueue on PREEMPT_RT

On Sat, Aug 16, 2025 at 10:16:34AM -0400, Alan Stern wrote:
> So it looks like we should be using a different function instead of 
> local_irq_disable().  We need something which in a non-RT build will 
> disable interrupts on the local CPU, but in an RT build will merely 
> disable preemption.  (In fact, every occurrence of local_irq_disable() 
> in the USB subsystem probably should be changed in this way.)

Or maybe what we need is something that in a non-RT build will disable 
local interrupts and in an RT build will do nothing.  (I suspect that RT 
kernels won't like it if we call spin_lock() while preemption is 
disabled.)

> Is there such a function?

Alan Stern