scsi: st: Fix a use after free in st_open()

In st_open(), if STp->in_use is true, STp will be freed by
scsi_tape_put(). However, STp is still used by DEBC_printk() after. It is
better to DEBC_printk() before scsi_tape_put().

Link: https://lore.kernel.org/r/20210311064636.10522-1-lyl2019@mail.ustc.edu.cn
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Lv Yunlong 2021-03-10 22:46:36 -08:00 committed by Martin K. Petersen
parent 2bb817712e
commit c8c165dea4

View File

@ -1269,8 +1269,8 @@ static int st_open(struct inode *inode, struct file *filp)
spin_lock(&st_use_lock);
if (STp->in_use) {
spin_unlock(&st_use_lock);
scsi_tape_put(STp);
DEBC_printk(STp, "Device already in use.\n");
scsi_tape_put(STp);
return (-EBUSY);
}