diff mbox series

[5.10,023/126] scsi: st: Fix a use after free in st_open()

Message ID 20210405085031.800513835@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman April 5, 2021, 8:53 a.m. UTC 
From: Lv Yunlong <lyl2019@mail.ustc.edu.cn>

[ Upstream commit c8c165dea4c8f5ad67b1240861e4f6c5395fa4ac ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/st.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e2e5356a997d..19bc8c923fce 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);
 	}