From nobody Fri Oct 2 04:41:31 2026 Received: from zg8tmtyylji0my4xnjeumjiw.icoremail.net (zg8tmtyylji0my4xnjeumjiw.icoremail.net [162.243.161.220]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5DC41448CFC; Wed, 5 Aug 2026 11:56:57 +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=1785931024; cv=none; b=TFdALPB6tLtWwZEtBmjkfn2pTZHZYo8KHg+erczSl97t4PK/Vl+rbUpuHa2CojdsRvZ4dHDH7sU5ogb7tdO4omu/tKG0l0ItLWidzpc5J787dw6tj4qzWXvdFQax4lZXs5rriuP1ehvqa5D35aYARPD0oEWO3VYZ7ZQbylAkkps= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785931024; c=relaxed/simple; bh=10kVQYRCo6bNJci1C7wNF0Cjviiqu8GTE57w1E5iKRo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=c44GVhu0RvR3Tm6rC8bJOPTyBqXmSU6E259IM+A9a+F1rCCVnQF+c6xIWfiE5qGC+SGeNEOMqTpdF3Zc3iarTHNX9CorlJtrcoP2vHmpJixKi1VRuvdmCILn1QVOS+0HOkaCNUjpm3AxI7u43oBrXgrigdo1dy5fMLv1Ro2p8j4= 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 [10.98.66.117]) by mtasvr (Coremail) with SMTP id _____wAX4n36JHNq4D9pAA--.20355S3; Wed, 05 Aug 2026 19:56:43 +0800 (CST) Received: from localhost.localdomain (unknown [10.98.66.117]) by mail-app1 (Coremail) with SMTP id yy_KCgAnd5_5JHNqa4iKAw--.51924S2; Wed, 05 Aug 2026 19:56:42 +0800 (CST) From: Fan Wu To: dri-devel@lists.freedesktop.org Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Marek Vasut , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Fan Wu Subject: [PATCH v2] drm/bridge: ti-sn65dsi83: Cancel reset_work on remove to avoid use-after-free Date: Wed, 5 Aug 2026 11:55:46 +0000 Message-Id: <20260805115546.152786-1-fanwu01@zju.edu.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260805090804.78914-1-fanwu01@zju.edu.cn> References: <20260805090804.78914-1-fanwu01@zju.edu.cn> 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: yy_KCgAnd5_5JHNqa4iKAw--.51924S2 X-CM-SenderInfo: qrstjiaswqq6lmxovvfxof0/ X-CM-DELIVERINFO: =?B?VLvJIwXKKxbFmtjJiESix3B1w3vZ3A9ovKVTomAyoQazvoRs/NHSP8GI2EvgeEEW7R sfnVCjTgEH9dVomQuWcozCBBHsHPRTq1nu9Lig+QZosvpoMyN+4DStAKd0ilpoZmfYoolR /bid1KQKukE0taufdXWp9E6mavGmQbzmcFsnzP86 X-Coremail-Antispam: 1Uk129KBj93XoWxur4fJw4fCrWkZF15Ww47ZFc_yoW5Ww1UpF sxW3s8C3ykXa1I9a9FyF15AFyYywnrtayrGrnrKw1fZa4Yqa15t34vkFWqqFyakFy8Jayj vr4qyFWkZr47AFcCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUP0b4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc804V CY07AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AK xVWUJVWUGwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48Icx kI7VAKI48JM4x0Y48IcxkI7VAKI48G6xCjnVAKz4kxM4IIrI8v6xkF7I0E8cxan2IY04v7 MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr 0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0E wIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JV WxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAI cVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU86c_DUUUUU== Content-Type: text/plain; charset="utf-8" The error recovery code queues reset_work from the threaded IRQ handler and polling monitor_work. Neither the remove path nor the probe failure path after the IRQ is registered drains that work before devres releases the bridge allocation. Use drm_bridge_unplug() before stopping the work. It prevents a concurrent atomic commit from entering the bridge and re-arming monitor_work through monitor_start(), and waits for in-flight bridge critical sections to finish. Then disable the IRQ and drain monitor_work and reset_work. Use the same shutdown sequence when attaching the DSI host fails. This prevents error recovery work queued by an early IRQ from accessing the devm-managed bridge after the failed probe returns. This issue was found by an in-house static analysis tool. Compile-tested only; runtime testing is appreciated. Fixes: ad5c6ecef27e ("drm: bridge: ti-sn65dsi83: Add error recovery mechani= sm") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu --- Changes since v1: - Move drm_bridge_unplug() ahead of the work cancellation so a concurrent atomic commit cannot re-arm monitor_work via monitor_start() after the cancel. - Drain from the probe-error path (err_remove_bridge) too, closing a UAF where a spurious IRQ during probe queues reset_work and a later -EPROBE_DEFER frees ctx. - Factor the sequence into sn65dsi83_stop_error_recovery() shared by both paths. drivers/gpu/drm/bridge/ti-sn65dsi83.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge= /ti-sn65dsi83.c index 42b451432bbb..5f1a96856eac 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c @@ -997,6 +997,18 @@ static irqreturn_t sn65dsi83_irq(int irq, void *data) return IRQ_HANDLED; } =20 +static void sn65dsi83_stop_error_recovery(struct sn65dsi83 *ctx) +{ + /* Block new bridge users and wait for existing critical sections. */ + drm_bridge_unplug(&ctx->bridge); + + if (ctx->irq) + disable_irq(ctx->irq); + + cancel_delayed_work_sync(&ctx->monitor_work); + cancel_work_sync(&ctx->reset_work); +} + static int sn65dsi83_probe(struct i2c_client *client) { const struct i2c_device_id *id =3D i2c_client_get_device_id(client); @@ -1061,7 +1073,7 @@ static int sn65dsi83_probe(struct i2c_client *client) return 0; =20 err_remove_bridge: - drm_bridge_remove(&ctx->bridge); + sn65dsi83_stop_error_recovery(ctx); return ret; } =20 @@ -1069,6 +1081,6 @@ static void sn65dsi83_remove(struct i2c_client *clien= t) { struct sn65dsi83 *ctx =3D i2c_get_clientdata(client); =20 - drm_bridge_unplug(&ctx->bridge); + sn65dsi83_stop_error_recovery(ctx); } =20 --=20 2.51.0