| Message ID | 20240318175021.22739-1-Alexander@wetzel-home.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scsi: sg: Avoid sg device teardown race | expand |
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 86210e4dd0d3..80e0d1981191 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2232,8 +2232,8 @@ sg_remove_sfp_usercontext(struct work_struct *work) "sg_remove_sfp: sfp=0x%p\n", sfp)); kfree(sfp); - scsi_device_put(sdp->device); kref_put(&sdp->d_ref, sg_device_destroy); + scsi_device_put(sdp->device); module_put(THIS_MODULE); }
sg_remove_sfp_usercontext() must not use sg_device_destroy() after calling scsi_device_put(). sg_device_destroy() is accessling the device queue. Which will be set to NULL if scsi_device_put() removes the last reference to the sg device. Link: https://lore.kernel.org/r/20240305150509.23896-1-Alexander@wetzel-home.de Cc: <stable@vger.kernel.org> Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de> --- This is my best shot for a real fix of the issue. I confirmed with printk's that I get the NULL pointer freeze ony when scsi_device_put() is deleting the last reference to the device. In the cases where it's not crashing there is still a reference left after the call. I don't see any obvious down side of simply swapping the calls. The alternative would by my first patch, just without the WARN_ON. Alexander --- drivers/scsi/sg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)