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 A421E27A133 for ; Wed, 13 May 2026 13:11:16 +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=1778677876; cv=none; b=fJgfH0uzsH3nZxINX5NQMrHvabJAWGWSk7o/lf1cc1xEeQ8nu2Xn70QbsJhT1ywZLaN81tZMyekxykJyeowN80v75INaXe3bfbn+BNx/HuBn3jMfA7fwNtQRp7+x/yk2wsOugwcOj1gAlb67APZCqVoKhbJ+hWIY+uVdEuVotn8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778677876; c=relaxed/simple; bh=/Fums9AIsXB5WN+kbao42/1zaVWUibjkfF3BnxWlcBs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZhuBrxqmOTcZJ9PmOK89DAcw1h5fqjipXJ12+SxOuhB07qrW1JIScRSDOJwLmt1xKdkUM0LdVPJCL5JGLzlhNJwayJc8Hk5qLzubyzY4eHTBem/UHcW+taiTJru25hIToUSLipARhhbC/KWwQ33j4bMMA4tbXXkZIITHQUBhpEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IurQqxZO; 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="IurQqxZO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E89CBC32781; Wed, 13 May 2026 13:11:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778677876; bh=/Fums9AIsXB5WN+kbao42/1zaVWUibjkfF3BnxWlcBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IurQqxZOumPRtLDlH0tMbxIFW/33B1vr9z1oSHwFMX4NJ/x0IXFK4aRueiLmZYGAY 6JGcns2Sjr5SmvgsbRwPsSBl96rCBW5N/e9vx/bfGCt4bu0MI9ktmbwLJKyFixJZwl 7FQ2lsQ0G533c1EQ75ciqHq9H7NSpQw0cimGovXneq17zVAkw/yOS/30HVT9rFv0Lh 8WuLz64tyVIyU5s/WrwYYlD91L15Z7FwRqWGcW0pQY+/swL/9yd5Xh1Frbql2ykK0Q nEYZZAVB7htZyGfJK9jpr9HgcUwMGD2Gpq7q+GOfMp55u+TPbilTSGPE/NddvL9kIK XTWVLiBKQ4sDQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Marek Szyprowski , Arend van Spriel , Johannes Berg , Sasha Levin Subject: [PATCH 5.15.y] wifi: brcmfmac: Fix potential use-after-free issue when stopping watchdog task Date: Wed, 13 May 2026 09:11:14 -0400 Message-ID: <20260513131114.3723069-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051207-posing-gauze-27af@gregkh> References: <2026051207-posing-gauze-27af@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 5006aa8317513..76b2953725c2d 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -2474,8 +2474,10 @@ 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