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| author | David Brownell <david-b@pacbell.net> | 2007-11-14 16:58:30 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-14 18:45:36 -0800 |
| commit | a4b1d50e6158ecaa8fdb6a716389149bace35b52 (patch) | |
| tree | 90649fc6d9bcf2aa2684fde7d982d0f752f1e9f4 /drivers/rtc/rtc-stk17ta8.c | |
| parent | 779d20892f8e716677194dc879eea2b5f1e75678 (diff) | |
| download | lwn-a4b1d50e6158ecaa8fdb6a716389149bace35b52.tar.gz lwn-a4b1d50e6158ecaa8fdb6a716389149bace35b52.zip | |
RTCs: handle NVRAM better
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>
Diffstat (limited to 'drivers/rtc/rtc-stk17ta8.c')
| -rw-r--r-- | drivers/rtc/rtc-stk17ta8.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-stk17ta8.c b/drivers/rtc/rtc-stk17ta8.c index 8288b6b2bf2b..a265da7c6ff8 100644 --- a/drivers/rtc/rtc-stk17ta8.c +++ b/drivers/rtc/rtc-stk17ta8.c @@ -291,7 +291,7 @@ static ssize_t stk17ta8_nvram_write(struct kobject *kobj, static struct bin_attribute stk17ta8_nvram_attr = { .attr = { .name = "nvram", - .mode = S_IRUGO | S_IWUGO, + .mode = S_IRUGO | S_IWUSR, .owner = THIS_MODULE, }, .size = RTC_OFFSET, |