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From: Oliver Neukum <oneukum@suse.com>
To: Alan Stern <stern@rowland.harvard.edu>, Oliver Neukum <oneukum@suse.com>
Cc: linux-usb@vger.kernel.org, tiwai@suse.com
Subject: Re: [PATCH] usb: core: hcd: fix possible deadlock in rh control transfers
Date: Wed, 29 Apr 2026 21:13:59 +0200	[thread overview]
Message-ID: <f579301d-75ce-4b72-991b-494201b7d1ef@suse.com> (raw)
In-Reply-To: <f54a001b-1825-46a3-a16e-946d88be8ded@rowland.harvard.edu>

On 29.04.26 21:04, Alan Stern wrote:

> Besides, even if a resume was necessary, wouldn't the same VM magic that
> works for the reset thread also work for the resume?  After all, they

They need not be the same thread. That is the point. usb_reset_device()
does a resume. However, it is possible for this to race with another thread
doing a resume or a suspend. In that case it will block and wait for
another thread. Hence we essentially get priority inversion more or
less.

	Regards
		Oliver




  reply	other threads:[~2026-04-29 19:14 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-25  2:12 [syzbot] [usb?] memory leak in hub_event (4) syzbot
2026-04-27 11:40 ` Oliver Neukum
2026-04-27 12:37   ` syzbot
2026-04-27 14:19   ` Alan Stern
2026-04-28 11:33     ` Oliver Neukum
2026-04-28 15:12       ` Alan Stern
2026-04-29 10:42 ` [PATCH] usb: core: hcd: fix possible deadlock in rh control transfers Oliver Neukum
2026-04-29 19:04   ` Alan Stern
2026-04-29 19:13     ` Oliver Neukum [this message]
2026-04-29 19:18       ` Alan Stern
2026-04-29 10:45 ` [PATCH] sound: usb: caiaq: fix reference leak in probe error Oliver Neukum
2026-04-29 10:53   ` Takashi Iwai
2026-04-29 11:05     ` Oliver Neukum
2026-04-29 19:42   ` kernel test robot
  -- strict thread matches above, loose matches on Subject: below --
2026-04-29  9:44 [PATCH] usb: core: hcd: fix possible deadlock in rh control transfers Oliver Neukum

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