Re: [PATRCH] janitor: hermes: delete verify_area call
flat view
From: Randy.Dunlap <hidden>
Date: 2003-09-29 20:06:08
On Mon, 29 Sep 2003 15:29:25 +1000 David Gibson [off-list ref] wrote:
| On Thu, Sep 25, 2003 at 09:59:02PM -0700, Randy.Dunlap wrote:
| >
| > Hi,
| > Please apply to 2.6.0-test5-current.
| >
| > Thanks,
|
| Sorry, can you clarify why this verify_area() is not needed?
Sure, I'll try to do that.
There are several related reasons for it.
Summary:
Using verify_area() [or access_ok()] is redundant if copy*user(),
get_user(), or put_user() is being used, but must (*should*) be used
if __copy*user(), __get_user(), or __put_user() are being used.
a. [include/asm-i386/uaccess.h] verify_area: - Obsolete, use access_ok()
b. copy_*_user() already calls access_ok() to validate the user address.
The __* versions of copy*user() and __get/put_user() do not use
access_ok(), so checking must be done before using them.
HTH.
--
~Randy
| From: Domen Puncer [off-list ref]
|
| IMO, that verify_area wasn't needed.
|
| linux-260-t5bk12-kj-rddunlap/drivers/net/wireless/orinoco.c | 4
| ----
| 1 files changed, 4 deletions(-)
|
| diff -puN drivers/net/wireless/orinoco.c~net_wireless_orinoco_verify
| +drivers/net/wireless/orinoco.c
| ---
| +linux-260-t5bk12-kj/drivers/net/wireless/orinoco.c~net_wireless_orinoco_verify
| +2003-09-25 16:03:17.000000000 -0700
| +++ linux-260-t5bk12-kj-rddunlap/drivers/net/wireless/orinoco.c
| 2003-09-25
| +16:03:17.000000000 -0700
| @@ -3833,10 +3833,6 @@ orinoco_ioctl(struct net_device *dev, st
| { SIOCIWLASTPRIV, 0, 0, "dump_recs" },
| };
|
| - err = verify_area(VERIFY_WRITE,
| wrq->u.data.pointer,
| +sizeof(privtab));
| - if (err)
| - break;
| -
| wrq->u.data.length = sizeof(privtab) /
| +sizeof(privtab[0]);
| if (copy_to_user(wrq->u.data.pointer, privtab,
| +sizeof(privtab)))
| err = -EFAULT;