[PATCH] wifi: ath9k: avoid device access after async firmware request

[PATCH] wifi: ath9k: avoid device access after async firmware request

[Yousef Alhouseen]

request_firmware_nowait() may invoke the callback before the requesting
context resumes. When a firmware lookup fails, the callback starts the
next fallback request. That nested request can exhaust the fallback list,
complete fw_done, and let disconnect free hif_dev before the parent request
returns.

The parent then dereferences hif_dev only to print a successful-request
message. Remove that post-request access so completion cannot leave an
older callback using the freed device state.

Fixes: e904cf6fe230 ("ath9k_htc: introduce support for different fw versions")
Reported-by: syzbot+cb7ed9d85261445a0201@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cb7ed9d85261445a0201
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 515267f48d80..aaf924cb8860 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -1222,9 +1222,6 @@ static int ath9k_hif_request_firmware(struct hif_device_usb *hif_dev,
 		return ret;
 	}
 
-	dev_info(&hif_dev->udev->dev, "ath9k_htc: Firmware %s requested\n",
-		 hif_dev->fw_name);
-
 	return ret;
 }
 
-- 
2.54.0

Re: [PATCH] wifi: ath9k: avoid device access after async firmware request

[Toke Høiland-Jørgensen]

Yousef Alhouseen <alhouseenyousef@gmail.com> writes:

> request_firmware_nowait() may invoke the callback before the requesting
> context resumes. When a firmware lookup fails, the callback starts the
> next fallback request. That nested request can exhaust the fallback list,
> complete fw_done, and let disconnect free hif_dev before the parent request
> returns.
>
> The parent then dereferences hif_dev only to print a successful-request
> message. Remove that post-request access so completion cannot leave an
> older callback using the freed device state.
>
> Fixes: e904cf6fe230 ("ath9k_htc: introduce support for different fw versions")
> Reported-by: syzbot+cb7ed9d85261445a0201@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=cb7ed9d85261445a0201
> Cc: stable@vger.kernel.org
> Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>

An identical patch was already submitted and is currently pending:
https://patchwork.kernel.org/project/linux-wireless/patch/20260605153210.20471-1-1020691186@qq.com/

-Toke

Re: [PATCH] wifi: ath9k: avoid device access after async firmware request

[Yousef Alhouseen]

Thanks for the pointer. I missed the pending patch; please drop mine.

Thanks,
Yousef

On Mon, 29 Jun 2026 11:49:34 +0200, "Toke Høiland-Jørgensen"
<toke@toke.dk> wrote:
> Yousef Alhouseen <alhouseenyousef@gmail.com> writes:
>
> > request_firmware_nowait() may invoke the callback before the requesting
> > context resumes. When a firmware lookup fails, the callback starts the
> > next fallback request. That nested request can exhaust the fallback list,
> > complete fw_done, and let disconnect free hif_dev before the parent request
> > returns.
> >
> > The parent then dereferences hif_dev only to print a successful-request
> > message. Remove that post-request access so completion cannot leave an
> > older callback using the freed device state.
> >
> > Fixes: e904cf6fe230 ("ath9k_htc: introduce support for different fw versions")
> > Reported-by: syzbot+cb7ed9d85261445a0201@syzkaller.appspotmail.com
> > Closes: https://syzkaller.appspot.com/bug?extid=cb7ed9d85261445a0201
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
>
> An identical patch was already submitted and is currently pending:
> https://patchwork.kernel.org/project/linux-wireless/patch/20260605153210.20471-1-1020691186@qq.com/
>
> -Toke