From: sashiko-bot@kernel.org
To: "Jing Lin" <kayano050408@gmail.com>
Cc: linux-usb@vger.kernel.org
Subject: Re: [PATCH v8 1/4] usb: gadget: gadgetfs: fix ep0 request lifetime and buffer races
Date: Tue, 10 Nov 2026 04:40:05 +0000 [thread overview]
Message-ID: <sashiko-outbox-206222@kernel.org> (raw)
In-Reply-To: <20261110-gadgetfs-ep0-v8-v8-1-8f90434574fe@gmail.com>
> From: Jing Lin <kayano050408@gmail.com>
>
> gadgetfs_unbind() frees the preallocated ep0 request after disconnecting
> the gadget, assuming that no I/O remains active.
>
> With controllers such as dummy_hcd, disconnecting does not necessarily
> drain ep0, so a delayed userspace response can leave dev->req queued
> when it is freed. This triggers the warning in dummy_free_request() and
> a use-after-free when dummy_udc_stop() subsequently drains the endpoint
> queue.
>
> gadgetfs_setup() and the userspace copy helpers also race on dev->req
> and req->buf:
>
> 1. ep0_read() versus gadgetfs_setup(). A delegated control OUT request
> [ ... ]
> Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
> Reported-by: syzbot+c73e1942197af9f54ca3@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=c73e1942197af9f54ca3
> Cc: stable@vger.kernel.org
> Signed-off-by: Jing Lin <kayano050408@gmail.com>
Sashiko has reviewed this patch and found no issues.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261110-gadgetfs-ep0-v8-v8-0-8f90434574fe@gmail.com?part=1
next prev parent reply other threads:[~2026-11-10 4:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-10 4:13 [PATCH v8 0/4] usb: gadget: gadgetfs: fix ep0 request lifetime and event counter Jing Lin via B4 Relay
2026-11-10 4:13 ` [PATCH v8 1/4] usb: gadget: gadgetfs: fix ep0 request lifetime and buffer races Jing Lin via B4 Relay
2026-11-10 4:40 ` sashiko-bot [this message]
2026-11-10 4:13 ` [PATCH v8 2/4] usb: gadget: gadgetfs: fix ep0 setup abort and unbind state races Jing Lin via B4 Relay
2026-11-10 4:36 ` sashiko-bot
2026-11-10 4:13 ` [PATCH v8 3/4] usb: gadget: gadgetfs: prevent ep0 event counter underflow Jing Lin via B4 Relay
2026-11-10 4:34 ` sashiko-bot
2026-11-10 4:13 ` [PATCH v8 4/4] usb: gadget: gadgetfs: avoid writing through the const setup pointer Jing Lin via B4 Relay
2026-11-10 4:18 ` sashiko-bot
2026-11-10 22:49 ` [PATCH v8 0/4] usb: gadget: gadgetfs: fix ep0 request lifetime and event counter Alan Stern
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