From nobody Thu Apr 2 00:08:12 2026 Received: from zg8tmtyylji0my4xnjeumjiw.icoremail.net (zg8tmtyylji0my4xnjeumjiw.icoremail.net [162.243.161.220]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 836EF341648; Tue, 10 Feb 2026 09:46:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.243.161.220 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770716762; cv=none; b=Cz/V0Itg+8/HxQ0vQN2ytv6beH+QkEE9ujujX8k8iHOB/DAI/8nY5qEX+J0htCPiKyf20jRAymE5yvKHlfU/iiNXggMc6cvejnX1lC+4Qzs+gGSXiZ3kRYEc/22B4isrm6gjHGrPm1g1joeCVUo3xh3ImOprsiVjYOmH95YODZI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770716762; c=relaxed/simple; bh=b0VHQrnV//St+64erztjcODCKRsWAEboNU8pL3PpInI=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=nkRh/Zwzq9Vcnx7gwuDkEfPO72RXyBupANqSKifKbn5ldlV0+UydsmnogU4e3Fhfbvmax9tzaaqCUNvbCeGAN5VTPrXVqP5cWzPkglj3hjFoyc9qtQ/sfCm2BI0NhYHxEVdsVX3cEac0P42SWo7mjpMJpkTJt7ABmUDY7RsbJlo= 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=162.243.161.220 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 [218.12.18.133]) by mtasvr (Coremail) with SMTP id _____wDn0OpJ_opprEKdAA--.35494S3; Tue, 10 Feb 2026 17:45:46 +0800 (CST) Received: from ubuntu.localdomain (unknown [218.12.18.133]) by mail-app3 (Coremail) with SMTP id zS_KCgD3+m1E_oppt9QmBg--.54003S2; Tue, 10 Feb 2026 17:45:44 +0800 (CST) From: Duoming Zhou To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-atm-general@lists.sourceforge.net, 3chas3@gmail.com, shaojijie@huawei.com, Duoming Zhou , stable@kernel.org Subject: [PATCH net v4] atm: fore200e: fix use-after-free in tasklets during device removal Date: Tue, 10 Feb 2026 17:45:37 +0800 Message-Id: <20260210094537.9767-1-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: zS_KCgD3+m1E_oppt9QmBg--.54003S2 X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwESAWmKOIcFcAARsp X-CM-DELIVERINFO: =?B?dmh97QXKKxbFmtjJiESix3B1w3uoVhYI+vyen2ZzBEkOnu5chDpkB+ZdGnv/zQ0PbP CR18B2QU8C4caAVCxk1uY0CQNLdDjtpdbRHujlG+Sokh+wh7uiETVID9oGi0+34vrlDCXG sqnA92P8zlcOdYr0TZSDnVaqya2ZGzIO9BYPl37ANvGUeXQULuRGIWsXP3MPcA== X-Coremail-Antispam: 1Uk129KBj93XoW7Kr43Kw43XF15WF4UWFyUJwc_yoW8Kr13p3 97CwsrCry8JrWjgw1UJw18uF18uFn3ZFWYkr4DK342qF1Yvr10vr18KFs8WFWqv34xZF92 gr1ktFyfG34DAFXCm3ZEXasCq-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. In a word, the tasklet_kill() should be placed in the FORE200E_STATE_IRQ branch within the switch...case structure. 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 Reviewed-by: Simon Horman --- Changes in v4: - Do tasklet_kill() in "switch(fore200e->state)-case FORE200E_STATE_IRQ" = branch. - Make the commit messages clearer. drivers/atm/fore200e.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c index f62e3857144..fec081db36d 100644 --- a/drivers/atm/fore200e.c +++ b/drivers/atm/fore200e.c @@ -373,6 +373,10 @@ fore200e_shutdown(struct fore200e* fore200e) fallthrough; case FORE200E_STATE_IRQ: free_irq(fore200e->irq, fore200e->atm_dev); +#ifdef FORE200E_USE_TASKLET + tasklet_kill(&fore200e->tx_tasklet); + tasklet_kill(&fore200e->rx_tasklet); +#endif =20 fallthrough; case FORE200E_STATE_ALLOC_BUF: --=20 2.34.1