From nobody Mon Dec 1 21:33:27 2025 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [52.229.205.26]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0ED2C199FB2; Mon, 1 Dec 2025 10:47:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.229.205.26 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764586052; cv=none; b=FDqMLM9n2fYO8lXMSlDjKf9waCQ5sJZ+yCqCgYgp1Luc4hBMcEPMZ7Uvd6BHqmGUELGIcKJA8SffVyAMKZkUBpz9AMx+DF2L7EyL1ROQ1e38yZnpJzpNaxcp/nvsn5NewjimumUDwFkq723UpV83fRCKr0RedafVNOJw0oIZ9KQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764586052; c=relaxed/simple; bh=zGUezxXGkLWBno8l9xQpOTdMBmDt5cjCB+yM8vPKqdM=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=j0xvlF9//48qaX9CFGQKTOtBmSPgKkslHDMKB+LnU497JQ12h1qgPbt+t13mKGlsxyadf+9g4ffGHtNl+Fq7an07TFphpVgQoc2YNwhqHJoXFeuS42HhZtL7f2OWODtyQwjPQBbi4cVSFeiKge28ipiofUud18L8wTFHzM4GuqA= 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=52.229.205.26 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 [218.12.21.37]) by mtasvr (Coremail) with SMTP id _____wAH_FAoci1pPQtnAA--.162S3; Mon, 01 Dec 2025 18:47:05 +0800 (CST) Received: from ubuntu.localdomain (unknown [218.12.21.37]) by mail-app4 (Coremail) with SMTP id zi_KCgCXT4Yjci1ptzKfAw--.13527S2; Mon, 01 Dec 2025 18:47:03 +0800 (CST) From: Duoming Zhou To: linux-scsi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, martin.petersen@oracle.com, James.Bottomley@HansenPartnership.com, Duoming Zhou , stable@kernel.org Subject: [PATCH] scsi: ppa: Fix use-after-free caused by unfinished delayed work Date: Mon, 1 Dec 2025 18:46:55 +0800 Message-Id: <20251201104655.13286-1-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: zi_KCgCXT4Yjci1ptzKfAw--.13527S2 X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwUHAWksngEI+AAfs1 X-CM-DELIVERINFO: =?B?m62WfAXKKxbFmtjJiESix3B1w3uoVhYI+vyen2ZzBEkOnu5chDpkB+ZdGnv/zQ0PbP CR1+OXM+ceWozZiJasFKyEGDC/hCTzRCaGYihPJJN3a1yGF9DrDiUB36IEyU/9iI3kAT9I 25iynK2FkUCgyVJ7LTLqOxtF0fvaBTwPUFtnKQy2ZCKUz6T9Wo2HR2QbHyhYKQ== X-Coremail-Antispam: 1Uk129KBj93XoW7Ar4fWr18Wry8tw47Jw13GFX_yoW8WrW7pr Z3Ca45ta9rWF409w47Xw48WFyfWrsxCrW5K3y0g3yfurn8JFy0vr1fta45ua48Jr40yw17 Ar4qqw18ZayqkFcCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUvvb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAF wI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0Y48IcxkI7V AKI48G6xCjnVAKz4kxMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I 3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxV WUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8I cVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aV AFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIevJa73UjIFyTuY vjxU26pBDUUUU Content-Type: text/plain; charset="utf-8" The delayed work item 'ppa_tq' is initialized in __ppa_attach() and scheduled via ppa_queuecommand() for processing SCSI commands. When the parallel port SCSI host adapter is detached through ppa_detach(), the ppa_struct device instance is deallocated. However, the delayed work might still be pending or executing when ppa_detach() is called, leading to use-after-free bugs when the work function ppa_interrupt() accesses the already freed ppa_struct memory. The race condition can occur as follows: CPU 0(detach thread) | CPU 1(delayed work) | ppa_queuecommand() | ppa_queuecommand_lck() ppa_detach() | schedule_delayed_work() kfree(dev) //FREE | ppa_interrupt() | dev =3D container_of(...) //USE dev-> //USE Add disable_delayed_work_sync() in ppa_detach() to guarantee proper cancellation of the delayed work item before ppa_struct is deallocated. This bug was identified through static analysis. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@kernel.org Signed-off-by: Duoming Zhou --- drivers/scsi/ppa.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/scsi/ppa.c b/drivers/scsi/ppa.c index ea682f3044b..8da2a78ebac 100644 --- a/drivers/scsi/ppa.c +++ b/drivers/scsi/ppa.c @@ -1136,6 +1136,7 @@ static void ppa_detach(struct parport *pb) ppa_struct *dev; list_for_each_entry(dev, &ppa_hosts, list) { if (dev->dev->port =3D=3D pb) { + disable_delayed_work_sync(&dev->ppa_tq); list_del_init(&dev->list); scsi_remove_host(dev->host); scsi_host_put(dev->host); --=20 2.34.1