[PATCH] st: fix potential null pointer dereference.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



If cdev_add() returns an error, the code calls
cdev_del() passing the STm->cdevs[rew] pointer as parameter;
the problem is that the pointer has not been initialized yet.

This patch fixes the problem by moving the STm->cdevs[rew] pointer
initialization before the call to cdev_add().
It also sets STm->devs[rew] = NULL if device_create() fails, just to be
sure we won't end up calling device_unregister() with an invalid pointer.

Signed-off-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
---
 drivers/scsi/st.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e0a1e52..dff3bdb 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4083,6 +4083,7 @@ static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
 	}
 	cdev->owner = THIS_MODULE;
 	cdev->ops = &st_fops;
+	STm->cdevs[rew] = cdev;
 
 	error = cdev_add(cdev, cdev_devno, 1);
 	if (error) {
@@ -4091,7 +4092,6 @@ static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
 		pr_err("st%d: Device not attached.\n", dev_num);
 		goto out_free;
 	}
-	STm->cdevs[rew] = cdev;
 
 	i = mode << (4 - ST_NBR_MODE_BITS);
 	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
@@ -4102,6 +4102,7 @@ static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
 	if (IS_ERR(dev)) {
 		pr_err("st%d: device_create failed\n", dev_num);
 		error = PTR_ERR(dev);
+		STm->devs[rew] = NULL;
 		goto out_free;
 	}
 
-- 
Maurizio Lombardi

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux