Hi! So let me investigate... Mainline fix is commit 83c6f2390040f188cc25b270b4befeb5628c1aee. Backport for 4.19 looks really easy, and I can't see anything wrong there: commit c45e3bcdebb204ef1ba1d00f41fe7ed39c4dd8cd Author: Pavel Machek Date: Thu May 14 23:47:42 2020 +0200 Backport. commit 83c6f2390040f188cc25b270b4befeb5628c1aee ... scsi: sg: add sg_remove_request in sg_write If the __copy_from_user function failed we need to call sg_remove_request in sg_write. Link: https://lore.kernel.org/r/610618d9-e983-fd56-ed0f-639428343af7@huawei.com Acked-by: Douglas Gilbert Signed-off-by: Wu Bo Signed-off-by: Martin K. Petersen diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 8a254bb46a9b..4f00d3062bd6 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -694,8 +694,10 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) hp->flags = input_size; /* structure abuse ... */ hp->pack_id = old_hdr.pack_id; hp->usr_ptr = NULL; - if (__copy_from_user(cmnd, buf, cmd_size)) + if (__copy_from_user(cmnd, buf, cmd_size)) { + sg_remove_request(sfp, srp); return -EFAULT; + } /* * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV, * but is is possible that the app intended SG_DXFER_TO_DEV, because there And I don't see a problem with 4.4, either. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html