From nobody Tue Feb 10 12:39:59 2026 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [52.175.55.52]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0093E36404D; Mon, 9 Feb 2026 09:45:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.175.55.52 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770630345; cv=none; b=FTiYDqEsnSAyrElFnwcAvyTxisbwVXF16JDiUl2ctxU3ID1vy18e5tD4mBnJuuJJ1XCpQWpXbYNk/abwCk+5Y2jUqnH20gl6EXOuYPivoSD/HUju72XuSeMgX1XKumrxUVPqcKkZuWMgbuMrXmaH8MS6uJkbO65U+g5+bEAEfmc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770630345; c=relaxed/simple; bh=i/8Mu9hmje5sRBexZMI0XKnRJ7nL6x+GoD+jELt/CJ8=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=DmMNOeZ/vfWHp8tOV/ayZPmNX/sG70PZjW6EwebVWumWSiIj+M8En4WGInOeQrsKBQsvhRkQ0JF+YhY0YCpgSPOJJixyeB+HHw6qrJi/GIQ2TjEqMbVMNO9F18iJ8igfM+NupoRZ3U8jg9HReRXMDf2lUR76ZRpgzivzV/8vUFc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=52.175.55.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from zju.edu.cn (unknown [218.12.16.96]) by mtasvr (Coremail) with SMTP id _____wDX3eWyrIlpKe2XAA--.23715S3; Mon, 09 Feb 2026 17:45:23 +0800 (CST) Received: from ubuntu.localdomain (unknown [218.12.16.96]) by mail-app2 (Coremail) with SMTP id zC_KCgB3kESprIlpzoC+BQ--.23042S2; Mon, 09 Feb 2026 17:45:17 +0800 (CST) From: Duoming Zhou To: netdev@vger.kernel.org Cc: 3chas3@gmail.com, linux-atm-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, shaojijie@huawei.com, Duoming Zhou , stable@kernel.org Subject: [PATCH net v3] atm: fore200e: fix use-after-free in tasklets during device removal Date: Mon, 9 Feb 2026 17:45:12 +0800 Message-Id: <20260209094512.33847-1-duoming@zju.edu.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zC_KCgB3kESprIlpzoC+BQ--.23042S2 X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwYRAWmI5wcH0wALsL X-CM-DELIVERINFO: =?B?fEFlVwXKKxbFmtjJiESix3B1w3uoVhYI+vyen2ZzBEkOnu5chDpkB+ZdGnv/zQ0PbP CR12qq1Zxbg26r1G9JjDbDDsSmmraU3VadI60SsWKFhc1LynJ8j/28Ljgx8w390ho8gFO0 gSVuLjRNfJqzyRNjVj7U8JEoHXDz9JPxKFqx8qzYj+I4gNee8NhIhdO8gaJ3cg== X-Coremail-Antispam: 1Uk129KBj93XoW7Kr43Kw43XF15WF4UWFyUJwc_yoW8trWxp3 yxGw47Cry8GrWj9w17Jw18uF18C3Z3XFWY9w4DK3y2qF1Yvry09r17tFWDWFWqk34xZF1v qr1ktFy3G34DAFXCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUvmb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAF wI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0Y48IcxkI7V AKI48G6xCjnVAKz4kxMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I 3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxV WUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8I cVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aV AFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZE Xa7IU801v3UUUUU== Content-Type: text/plain; charset="utf-8" When the PCA-200E or SBA-200E adapter is being detached, the fore200e is deallocated. However, the tx_tasklet or rx_tasklet may still be running or pending, leading to use-after-free bug when the already freed fore200e is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet(). One of the race conditions can occur as follows: CPU 0 (cleanup) | CPU 1 (tasklet) fore200e_pca_remove_one() | fore200e_interrupt() fore200e_shutdown() | tasklet_schedule() kfree(fore200e) | fore200e_tx_tasklet() | fore200e-> // UAF Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to synchronize with any pending or running tasklets. Moreover, since fore200e_reset() could prevent further interrupts or data transfers, the tasklet_kill() should be placed after fore200e_reset() to prevent the tasklet from being rescheduled in fore200e_interrupt(). Finally, it only needs to do tasklet_kill() when the fore200e state is greater than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized in earlier states. This bug was identified through static analysis. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@kernel.org Suggested-by: Jijie Shao Signed-off-by: Duoming Zhou Reviewed-by: Jijie Shao --- Changes in v3: - Only do tasklet_kill() when state >=3D FORE200E_STATE_IRQ. - Make the commit messages clearer. drivers/atm/fore200e.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c index f62e3857144..eb386ec6b5e 100644 --- a/drivers/atm/fore200e.c +++ b/drivers/atm/fore200e.c @@ -363,7 +363,12 @@ fore200e_shutdown(struct fore200e* fore200e) /* first, reset the board to prevent further interrupts or data transfers= */ fore200e_reset(fore200e, 0); } - =20 +#ifdef FORE200E_USE_TASKLET + if (fore200e->state >=3D FORE200E_STATE_IRQ) { + tasklet_kill(&fore200e->tx_tasklet); + tasklet_kill(&fore200e->rx_tasklet); + } +#endif /* then, release all allocated resources */ switch(fore200e->state) { =20 --=20 2.34.1