From nobody Fri Oct 3 15:32:52 2025 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [52.237.72.81]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 31C872BB13; Thu, 28 Aug 2025 08:30:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.237.72.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756369834; cv=none; b=J9GvELWewY5S4uQcpSfSEcFJ7Txtmg7LtA0fHUlyzBZkkP82t/cVJRBUvqptAJNpzuh/H/aHF/riXiSQsL743yxz8cnzVyxUsKRDwzRGd/WUlziKaJnQvrCMQpqWJ/Wle2vMeg03Dy8QXVGape4i6teT/YLGMtepb+ZAb2erHcc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756369834; c=relaxed/simple; bh=lYvOkaqSmiPB3fPDePClMUAcE7IkORIZ2YlXR6J25JE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=JunvWI14VZ+ztyDD7fEUqgx1o4IELkuRgS2mFICZmaTmUFIDAwGv9hiREOkePJ0BhZI6wwXR8tgAZc51dT6+agIg2ryJWhuTqjnn+sTfwflElS+7bxGwh8NQxPgqSBISQ6EtonWtVbEL/A3Ig4ocuCERuXlc0MMr3gfYDjmG/Vo= 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=52.237.72.81 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 [218.12.22.77]) by mtasvr (Coremail) with SMTP id _____wBXo0GFE7BoaXOmAQ--.35203S3; Thu, 28 Aug 2025 16:29:58 +0800 (CST) Received: from ubuntu.localdomain (unknown [218.12.22.77]) by mail-app3 (Coremail) with SMTP id zS_KCgC3uGt_E7Bo4vgRAg--.32381S2; Thu, 28 Aug 2025 16:29:56 +0800 (CST) From: Duoming Zhou To: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, davem@davemloft.net, andrew+netdev@lunn.ch, vadim.fedorenko@linux.dev, jonathan.lemon@gmail.com, richardcochran@gmail.com, Duoming Zhou Subject: [PATCH net] ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog Date: Thu, 28 Aug 2025 16:29:49 +0800 Message-Id: <20250828082949.28189-1-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_KCgC3uGt_E7Bo4vgRAg--.32381S2 X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwYMAWivX3kKvwA9sh X-CM-DELIVERINFO: =?B?tDe5dwXKKxbFmtjJiESix3B1w3uoVhYI+vyen2ZzBEkOnu5chDpkB+ZdGnv/zQ0PbP CR14rLicSpEjZUZiR0XyfQpfqCNvLUJpn3cUPDpJvueWGVIASmmDqvMev1Dccqs2H3z1uh i0RlUb/Ldsdi21hmwFQW6Se2hnaYR5/2T5LD0dLogoMhDa3yq0Flmth1VeHgmA== X-Coremail-Antispam: 1Uk129KBj93XoW7WFy7KFW8try3Kr15CrW8Zrc_yoW8XFy5pr WkGw43Ar1jqr4UCa1vqr1kJFyruayvvFy0yw4rKwn8Z3Z8WF1SqF4rKw4jgayqkrWDWr1S yF4Fq3y5AFnYk3gCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Kb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAF wI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0Y48IcxkI7V AKI48G6xCjnVAKz4kxM4IIrI8v6xkF7I0E8cxan2IY04v7MxAIw28IcxkI7VAKI48JMxC2 0s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI 0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE 14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20x vaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWU JVW8JbIYCTnIWIevJa73UjIFyTuYvjxU7xwIDUUUU Content-Type: text/plain; charset="utf-8" The ptp_ocp_detach() only shuts down the watchdog timer if it is pending. However, if the timer handler is already running, the timer_delete_sync() is not called. This leads to race conditions where the devlink that contains the ptp_ocp is deallocated while the timer handler is still accessing it, resulting in use-after-free bugs. The following details one of the race scenarios. (thread 1) | (thread 2) ptp_ocp_remove() | ptp_ocp_detach() | ptp_ocp_watchdog() if (timer_pending(&bp->watchdog))| bp =3D timer_container_of() timer_delete_sync() | | devlink_free(devlink) //free | | bp-> //use Resolve this by unconditionally calling timer_delete_sync() to ensure the timer is reliably deactivated, preventing any access after free. Fixes: 773bda964921 ("ptp: ocp: Expose various resources on the timecard.") Signed-off-by: Duoming Zhou Reviewed-by: Vadim Fedorenko --- drivers/ptp/ptp_ocp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index d39073dc4072..4e1286ce05c9 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -4557,8 +4557,7 @@ ptp_ocp_detach(struct ptp_ocp *bp) ptp_ocp_debugfs_remove_device(bp); ptp_ocp_detach_sysfs(bp); ptp_ocp_attr_group_del(bp); - if (timer_pending(&bp->watchdog)) - timer_delete_sync(&bp->watchdog); + timer_delete_sync(&bp->watchdog); if (bp->ts0) ptp_ocp_unregister_ext(bp->ts0); if (bp->ts1) --=20 2.34.1