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 C40EB25FA29; Tue, 12 May 2026 18:03:35 +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=1778609015; cv=none; b=AN5GwUp5IKUSaTMlTW2DMIRtlAOByegSxqAmBtVpYYdgIVGsvSysjuf1LajgrWWxjxqkVwBxq03b9EYZWiKEFSzR5TSLgjcS5k+bdwF3d03TShJS74wdqt8XcVRWNGaQ5x0SdEYb/B29AAbXWTrjPLfqoFEbMZE3aK8cRirYsUU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778609015; c=relaxed/simple; bh=j/woUSMhCVHk5ZrZmOdsOPwfSad3rNN3iSUOQB9v0To=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fgDxnqdadJiaw83QMrQ49Gn43yiE9HfaaENDCAojb3ZoW1eqp1PMq8Or2jprixYDKEWyKHpBDV2kVaWXAzycqOOC9b5Y2Vnl84z8SRkrEVb9G1KPFLxZW30AyXqWqPs5dF+xhhODUr6sHHSFGNoavt273KTurNW1nc7B21Ze0jY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bzSFMJdu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bzSFMJdu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26FF2C2BCB0; Tue, 12 May 2026 18:03:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778609015; bh=j/woUSMhCVHk5ZrZmOdsOPwfSad3rNN3iSUOQB9v0To=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bzSFMJduA1d3KrfIvZTs1rE6IUP9+ZanrtIFL1D2kmWXkVqmf405TD+vaP11xn+lm 4+ocs4ulHtMyjkfVHnw9elkzghCqm3NHGkcqCb17v5/G8cdx/OOUWecNR17pVHOeMb 8cj8V2xBRefLU9uouRYdwPzBPtFYszc3BjTX4sq0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marek Szyprowski , Arend van Spriel , Johannes Berg Subject: [PATCH 7.0 033/307] wifi: brcmfmac: Fix potential use-after-free issue when stopping watchdog task Date: Tue, 12 May 2026 19:37:08 +0200 Message-ID: <20260512173940.826087445@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260512173940.117428952@linuxfoundation.org> References: <20260512173940.117428952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Szyprowski commit c623b63580880cc742255eaed3d79804c1b91143 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -2476,8 +2476,9 @@ static void brcmf_sdio_bus_stop(struct d 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); + kthread_stop_put(bus->watchdog_tsk); bus->watchdog_tsk = NULL; } @@ -4567,8 +4568,9 @@ void brcmf_sdio_remove(struct brcmf_sdio 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); + kthread_stop_put(bus->watchdog_tsk); bus->watchdog_tsk = NULL; }