From 454e8957eb60841016deb319dbbf83042fb32a39 Mon Sep 17 00:00:00 2001 From: Ishai Rabinovitz Date: Thu, 29 Jun 2006 16:39:54 +0300 Subject: [PATCH] [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 Acked-by: Douglas Gilbert Signed-off-by: James Bottomley --- drivers/scsi/sg.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 98b9312ba8da..d5bbb97bb74b 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -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) -- 2.30.2