From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 45360426699 for ; Wed, 13 May 2026 12:48:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778676524; cv=none; b=QGU3zb50m44i9y0BJ9pw2p56/x7OMExRJlibF3THbfD5BF8A4btRFJP7Ee4P03JIkjo9K7fwE5l2+krResJ/CnnKwuAkUe9n0MNTUE4vhDaxpYqKWoEUb2FAvBM1KJ93C7QX+SgyxJ9SsZaZbIEsAjS3RGUlfGLqNSvl1NTany8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778676524; c=relaxed/simple; bh=nBTOImue/7Ox3okmnQuOqwPuv8DYIODfrumCVl5ZVOI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SCVsb8suHkGZFA8FikpC4PiS0cx74VFzf8LZf4UuidXU9MMNSKE8sWmVtNd3XN4wlzmJGgIERpEc1M8pw7VAdgmZwQTPQK782sNCuUWvZjv1hT+IVLgMk5zztFxQNddWqvgE1xEU7cCm8yuWxVr2UtnzI3VvV9EPhKa9nN9MF3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gak/LPfN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gak/LPfN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19140C2BCC7; Wed, 13 May 2026 12:48:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778676523; bh=nBTOImue/7Ox3okmnQuOqwPuv8DYIODfrumCVl5ZVOI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gak/LPfNO5t7SvtyLnecZ0Eojd5dqjhf8JgaPAmPuBzu4cbVUlZUHOAYubDOUEnXG MU8MV/tD95uBw8QRGeM+Wl/H1UzPWnFn/d/U27cLx567Iochoks/A1K2kb4fEFkCKi wScuXyXPjSo2MqbpwNGS/RCYjUvqkXLuujybRJ9aC4Vzu/+ikFm4h2O3/dNemv4Aw6 A+sEtaeHmkRcnSn2MtOQHUWSk3nPaU6wStrlh9qfqAgxPiOrjED7W0aCvcJeGeVkWn cm/SVCkt7RDVmtyV2I9RTAZ8PIa8HVzj0chKTplythFKEhkwRs0kVUeaXMfW7OahFk BFMoXAT4+vxTA== From: Sasha Levin To: stable@vger.kernel.org Cc: Marek Szyprowski , Arend van Spriel , Johannes Berg , Sasha Levin Subject: [PATCH 6.1.y] wifi: brcmfmac: Fix potential use-after-free issue when stopping watchdog task Date: Wed, 13 May 2026 08:48:41 -0400 Message-ID: <20260513124841.3712467-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051206-scalded-clone-94cb@gregkh> References: <2026051206-scalded-clone-94cb@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Marek Szyprowski [ Upstream commit c623b63580880cc742255eaed3d79804c1b91143 ] Watchdog task might end between send_sig() and kthread_stop() calls, what results in the use-after-free issue. Fix this by increasing watchdog task reference count before calling send_sig() and dropping it by switching to kthread_stop_put(). Cc: stable@vger.kernel.org Fixes: 373c83a801f1 ("brcmfmac: stop watchdog before detach and free everything") Fixes: a9ffda88be74 ("brcm80211: fmac: abstract bus_stop interface function pointer") Signed-off-by: Marek Szyprowski Acked-by: Arend van Spriel Link: https://patch.msgid.link/20260416093339.2066829-1-m.szyprowski@samsung.com Signed-off-by: Johannes Berg [ replaced kthread_stop_put() with open-coded kthread_stop() + put_task_struct() ] Signed-off-by: Sasha Levin --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c index e265a2e411a09..5f6c0afe22d49 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -2477,8 +2477,10 @@ static void brcmf_sdio_bus_stop(struct device *dev) brcmf_dbg(TRACE, "Enter\n"); if (bus->watchdog_tsk) { + get_task_struct(bus->watchdog_tsk); send_sig(SIGTERM, bus->watchdog_tsk, 1); kthread_stop(bus->watchdog_tsk); + put_task_struct(bus->watchdog_tsk); bus->watchdog_tsk = NULL; } @@ -4549,8 +4551,10 @@ void brcmf_sdio_remove(struct brcmf_sdio *bus) if (bus) { /* Stop watchdog task */ if (bus->watchdog_tsk) { + get_task_struct(bus->watchdog_tsk); send_sig(SIGTERM, bus->watchdog_tsk, 1); kthread_stop(bus->watchdog_tsk); + put_task_struct(bus->watchdog_tsk); bus->watchdog_tsk = NULL; } -- 2.53.0