From c8c165dea4c8f5ad67b1240861e4f6c5395fa4ac Mon Sep 17 00:00:00 2001 From: Lv Yunlong Date: Wed, 10 Mar 2021 22:46:36 -0800 Subject: [PATCH] scsi: st: Fix a use after free in st_open() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Lv Yunlong Signed-off-by: Martin K. Petersen --- drivers/scsi/st.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 841ad2fc369a..9ca536aae784 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -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); }