[SCSI] sg.c: Fix bad error handling in

I got a NULL derefrence in cdev_del+1 when called from sg_remove. By looking at
the code of sg_add, sg_alloc and sg_remove (all in drivers/scsi/sg.c) I found
out that sg_add is calling sg_alloc but if it fails afterwards it does not
deallocate the space that was allocated in sg_alloc and the redundant entry has
NULL in cdev. When sg_remove is being called, it tries to perform cdev_del to
this NULL cdev and fails.

Signed-off-by: Ishai Rabinovitz <ishai@mellanox.co.il>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
Ishai Rabinovitz 2006-06-29 16:39:54 +03:00 committed by James Bottomley
parent 0f13fc09db
commit 454e8957eb

View File

@ -1402,6 +1402,7 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
Sg_device *sdp = NULL;
struct cdev * cdev = NULL;
int error, k;
unsigned long iflags;
disk = alloc_disk(1);
if (!disk) {
@ -1429,7 +1430,7 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
if (error)
goto out;
goto cdev_add_err;
sdp->cdev = cdev;
if (sg_sysfs_valid) {
@ -1456,6 +1457,13 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
return 0;
cdev_add_err:
write_lock_irqsave(&sg_dev_arr_lock, iflags);
kfree(sg_dev_arr[k]);
sg_dev_arr[k] = NULL;
sg_nr_dev--;
write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
out:
put_disk(disk);
if (cdev)