Several of the RTC drivers are exporting binary "nvram" files in sysfs. Such
NVRAM (or on many systems, EEPROM) data is often initialized during system
manufacture to hold data about identity (serial numbers, Ethernet addresses,
etc), configuration, calibration, and so forth.
This patch improves integrity and security of those files:
- Correctly initializes the size in one of the two cases where
that was not yet being done.
- Improves system security/integrity by making this state not
be world-writable by default.
Letting arbitrary userspace code mangle such state by default is at least Not
A Good Thing; and it could sometimes be worse, depending on the particular
data that might be corrupted. (I disregard the paranoiac "don't let anyone
read it either" approach. Anyone storing passwords in such memory doesn't
really care about security.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Torsten Ertbjerg Rasmussen <tr@newtec.dk>
Cc: Mark Zhan <rongkai.zhan@windriver.com>
Cc: Thomas Hommel <thomas.hommel@gefanuc.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the name of this data to use a name (suffix) that is whitelisted
by MODPOST so that the section warning is fixed (not generated).
WARNING: vmlinux.o(.data+0x1b140): Section mismatch: reference to .init.text:m48t59_rtc_probe (between 'm48t59_rtc_platdrv' and 'm48t59_nvram_attr')
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since irq in m48t59_private struct is defined as 'unsigned int', which will
make the following if sentence to be never true:
if (m48t59->irq < 0)
m48t59->irq = NO_IRQ;
And thus it will make the m48t59_rtc_probe() is failed when the driver is
working in a no irq mode:
Signed-off-by: Mark Zhan <rongkai.zhan@windriver.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Brownell
Randy Dunlap
Mark Zhan