Messages in this thread | | | From | Robert Jarzmik <> | Subject | Re: Stricter module param and sysfs permission checks | Date | Thu, 20 Mar 2014 17:28:50 +0100 |
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Dave Jones <davej@redhat.com> writes:
> On Thu, Mar 20, 2014 at 01:43:44PM +1030, Rusty Russell wrote: > > > drivers/mtd/devices/docg3.c: > > __ATTR(f##id##_dps0_protection_key, S_IWUGO, NULL, dps0_insert_key), \ > > __ATTR(f##id##_dps1_protection_key, S_IWUGO, NULL, dps1_insert_key), \ > > > > drivers/scsi/pm8001/pm8001_ctl.c: > > static DEVICE_ATTR(update_fw, S_IRUGO|S_IWUGO, > > pm8001_show_update_fw, pm8001_store_update_fw); > > Why on earth are these world writable ? For docg3, this attributes are used to input a "password" into the flash chip, to unlock parts of the flash memory. By unlock I mean that a sector read will return the actual sector when unlocked, and only 0xff if not read unlocked.
As to the "why writable" by "others", the legacy reason is that when I wrote that code I had in mind that a casual user count : - input the code : "echo secret > dps0_protection_key" - mount /usermount
That's not a good reason, I know, and changing that to remove the "other" write permission is fine by me.
Cheers.
-- Robert
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