From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E0BB2FDC5E; Tue, 31 Mar 2026 17:06:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976807; cv=none; b=SB0EHbNraDzMZDjsCQXUQZAKU0jUITM3cd3/Wy/bDh2t5SwJGtINUqRX+y/lb3snvP+Uk6zNYUB+VUz62oAp0103Bs7n1CCnkIQPpeP99/O9fRj6F8Ox9rg/QLGNxY3WJK4FZXRuF0OAfD7S42/Im61wGcvw/eWWcHAZdqjRDUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976807; c=relaxed/simple; bh=nAR56JV0MzBG9hq6N65AQuzWlrBoy6kf+BjDl+kTZZc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fl5ttZqb5YsbxDsjA2RcrKXvdO6joWRZobb7Q46+O0XxoWeRW37gW1VyVm/oM5YKND/XjpBCJaHi1p39BkI1awqqoSfN6SnUHyUYkEkeD7Q1xY06tBwjmFxqzT/ki1PuLTCWM6TA+Z75qk+aTW3+HIr2FCa0VOVL1BvuXb4wgjM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mEH/sIvr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mEH/sIvr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14AD8C19423; Tue, 31 Mar 2026 17:06:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976807; bh=nAR56JV0MzBG9hq6N65AQuzWlrBoy6kf+BjDl+kTZZc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mEH/sIvrj46pwEw+XovuvcttK7bOCWSitqCTXwjYw7haq9EWJBlN9qeprEfwqdt5s Lr4eMUiIsGuUNXumrWwr6WzX3QhYuqimQ0M/OCojhHg9a+N7mdr9uQtgk0+W+pQjIP MJNq65PaJXUPC/CDFLb1RnMvkCqJtwPKihAQRNhg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuchan Nam , Sakari Ailus , Mauro Carvalho Chehab Subject: [PATCH 6.18 203/309] media: mc, v4l2: serialize REINIT and REQBUFS with req_queue_mutex Date: Tue, 31 Mar 2026 18:21:46 +0200 Message-ID: <20260331161800.924011881@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuchan Nam commit bef4f4a88b73e4cc550d25f665b8a9952af22773 upstream. MEDIA_REQUEST_IOC_REINIT can run concurrently with VIDIOC_REQBUFS(0) queue teardown paths. This can race request object cleanup against vb2 queue cancellation and lead to use-after-free reports. We already serialize request queueing against STREAMON/OFF with req_queue_mutex. Extend that serialization to REQBUFS, and also take the same mutex in media_request_ioctl_reinit() so REINIT is in the same exclusion domain. This keeps request cleanup and queue cancellation from running in parallel for request-capable devices. Fixes: 6093d3002eab ("media: vb2: keep a reference to the request until dqbuf") Cc: stable@vger.kernel.org Signed-off-by: Yuchan Nam Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/mc/mc-request.c | 5 +++++ drivers/media/v4l2-core/v4l2-ioctl.c | 5 +++-- 2 files changed, 8 insertions(+), 2 deletions(-) --- a/drivers/media/mc/mc-request.c +++ b/drivers/media/mc/mc-request.c @@ -190,6 +190,8 @@ static long media_request_ioctl_reinit(s struct media_device *mdev = req->mdev; unsigned long flags; + mutex_lock(&mdev->req_queue_mutex); + spin_lock_irqsave(&req->lock, flags); if (req->state != MEDIA_REQUEST_STATE_IDLE && req->state != MEDIA_REQUEST_STATE_COMPLETE) { @@ -197,6 +199,7 @@ static long media_request_ioctl_reinit(s "request: %s not in idle or complete state, cannot reinit\n", req->debug_str); spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); return -EBUSY; } if (req->access_count) { @@ -204,6 +207,7 @@ static long media_request_ioctl_reinit(s "request: %s is being accessed, cannot reinit\n", req->debug_str); spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); return -EBUSY; } req->state = MEDIA_REQUEST_STATE_CLEANING; @@ -214,6 +218,7 @@ static long media_request_ioctl_reinit(s spin_lock_irqsave(&req->lock, flags); req->state = MEDIA_REQUEST_STATE_IDLE; spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); return 0; } --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3079,13 +3079,14 @@ static long __video_do_ioctl(struct file } /* - * We need to serialize streamon/off with queueing new requests. + * We need to serialize streamon/off/reqbufs with queueing new requests. * These ioctls may trigger the cancellation of a streaming * operation, and that should not be mixed with queueing a new * request at the same time. */ if (v4l2_device_supports_requests(vfd->v4l2_dev) && - (cmd == VIDIOC_STREAMON || cmd == VIDIOC_STREAMOFF)) { + (cmd == VIDIOC_STREAMON || cmd == VIDIOC_STREAMOFF || + cmd == VIDIOC_REQBUFS)) { req_queue_lock = &vfd->v4l2_dev->mdev->req_queue_mutex; if (mutex_lock_interruptible(req_queue_lock))