From 4cc664e59bf2553771e4c9e90f758f7434cfdc22 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Sat, 10 Jun 2023 10:20:02 +0800 Subject: [PATCH] scsi: sg: fix blktrace debugfs entries leakage [ Upstream commit db59133e927916d8a25ee1fd8264f2808040909d ] sg_ioctl() support to enable blktrace, which will create debugfs entries "/sys/kernel/debug/block/sgx/", however, there is no guarantee that user will remove these entries through ioctl, and deleting sg device doesn't cleanup these blktrace entries. This problem can be fixed by cleanup blktrace while releasing request_queue, however, it's not a good idea to do this special handling in common layer just for sg device. Fix this problem by shutdown bltkrace in sg_device_destroy(), where the device is deleted and all the users close the device, also grab a scsi_device reference from sg_add_device() to prevent scsi_device to be freed before sg_device_destroy(); Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20230610022003.2557284-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/scsi/sg.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 037f8c98a6d3..0adfbd77437f 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1496,6 +1496,10 @@ sg_add_device(struct device *cl_dev) int error; unsigned long iflags; + error = scsi_device_get(scsidp); + if (error) + return error; + error = -ENOMEM; cdev = cdev_alloc(); if (!cdev) { @@ -1553,6 +1557,7 @@ cdev_add_err: out: if (cdev) cdev_del(cdev); + scsi_device_put(scsidp); return error; } @@ -1560,6 +1565,7 @@ static void sg_device_destroy(struct kref *kref) { struct sg_device *sdp = container_of(kref, struct sg_device, d_ref); + struct request_queue *q = sdp->device->request_queue; unsigned long flags; /* CAUTION! Note that the device can still be found via idr_find() @@ -1567,6 +1573,9 @@ sg_device_destroy(struct kref *kref) * any other cleanup. */ + blk_trace_remove(q); + scsi_device_put(sdp->device); + write_lock_irqsave(&sg_index_lock, flags); idr_remove(&sg_index_idr, sdp->index); write_unlock_irqrestore(&sg_index_lock, flags);