The patch titled
RTCs: handle NVRAM better
has been added to the -mm tree. Its filename is
rtcs-handle-nvram-better.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: RTCs: handle NVRAM better
From: David Brownell <david-b@xxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxx>
Acked-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
Cc: Torsten Ertbjerg Rasmussen <tr@xxxxxxxxx>
Cc: Mark Zhan <rongkai.zhan@xxxxxxxxxxxxx>
Cc: Thomas Hommel <thomas.hommel@xxxxxxxxxxx>
Acked-by: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-ds1553.c | 2 +-
drivers/rtc/rtc-ds1742.c | 5 ++++-
drivers/rtc/rtc-m48t59.c | 3 ++-
drivers/rtc/rtc-stk17ta8.c | 2 +-
4 files changed, 8 insertions(+), 4 deletions(-)
diff -puN drivers/rtc/rtc-ds1553.c~rtcs-handle-nvram-better drivers/rtc/rtc-ds1553.c
--- a/drivers/rtc/rtc-ds1553.c~rtcs-handle-nvram-better
+++ a/drivers/rtc/rtc-ds1553.c
@@ -291,7 +291,7 @@ static ssize_t ds1553_nvram_write(struct
static struct bin_attribute ds1553_nvram_attr = {
.attr = {
.name = "nvram",
- .mode = S_IRUGO | S_IWUGO,
+ .mode = S_IRUGO | S_IWUSR,
},
.size = RTC_OFFSET,
.read = ds1553_nvram_read,
diff -puN drivers/rtc/rtc-ds1742.c~rtcs-handle-nvram-better drivers/rtc/rtc-ds1742.c
--- a/drivers/rtc/rtc-ds1742.c~rtcs-handle-nvram-better
+++ a/drivers/rtc/rtc-ds1742.c
@@ -160,10 +160,13 @@ static ssize_t ds1742_nvram_write(struct
static struct bin_attribute ds1742_nvram_attr = {
.attr = {
.name = "nvram",
- .mode = S_IRUGO | S_IWUGO,
+ .mode = S_IRUGO | S_IWUSR,
},
.read = ds1742_nvram_read,
.write = ds1742_nvram_write,
+ /* REVISIT: size in sysfs won't match actual size... if it's
+ * not a constant, each RTC should have its own attribute.
+ */
};
static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
diff -puN drivers/rtc/rtc-m48t59.c~rtcs-handle-nvram-better drivers/rtc/rtc-m48t59.c
--- a/drivers/rtc/rtc-m48t59.c~rtcs-handle-nvram-better
+++ a/drivers/rtc/rtc-m48t59.c
@@ -353,11 +353,12 @@ static ssize_t m48t59_nvram_write(struct
static struct bin_attribute m48t59_nvram_attr = {
.attr = {
.name = "nvram",
- .mode = S_IRUGO | S_IWUGO,
+ .mode = S_IRUGO | S_IWUSR,
.owner = THIS_MODULE,
},
.read = m48t59_nvram_read,
.write = m48t59_nvram_write,
+ .size = M48T59_NVRAM_SIZE,
};
static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
diff -puN drivers/rtc/rtc-stk17ta8.c~rtcs-handle-nvram-better drivers/rtc/rtc-stk17ta8.c
--- a/drivers/rtc/rtc-stk17ta8.c~rtcs-handle-nvram-better
+++ a/drivers/rtc/rtc-stk17ta8.c
@@ -291,7 +291,7 @@ static ssize_t stk17ta8_nvram_write(stru
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,
_
Patches currently in -mm which might be from david-b@xxxxxxxxxxx are
origin.patch
rtc-m48t59-fix-section-mismatch-warning.patch
rtc_hctosys-expects-rtcs-in-utc-doc.patch
rtcs-handle-nvram-better.patch
rtc-ds1307-exports-nvram.patch
rtc-dont-write-rtc-century-when-setting-a-wake-alarm.patch
usb-s3c2410_udc-minor-irq-handler-cleanups.patch
pci-add-pci-identifiers-for-the-rdc-devices.patch
x86-add-support-for-the-rdc-r-321x-soc.patch
add-the-rdc-machine-specific-reboot-fixup.patch
rtc-release-correct-region-in-error-path.patch
rtc-fallback-to-requesting-only-the-ports-we-actually-use.patch
tle62x0-driver-stops-ignoring-read-errors.patch
rtc-convert-mutex-to-bitfield.patch
drivers-pmc-msp71xx-gpio-char-driver.patch
remove-pointless-casts-from-void-pointers.patch
spi-at25-driver-is-for-eeprom-not-flash.patch
spi-use-mutex-not-semaphore.patch
blackfin-spi-driver-use-cpu_relax-to-replace-continue-in-while-busywait.patch
blackfin-spi-driver-use-void-__iomem-for-regs_base.patch
blackfin-spi-driver-move-hard-coded-pin_req-to-board-file.patch
blackfin-spi-driver-reconfigure-speed_hz-and-bits_per_word-in-each-spi-transfer.patch
cosmetic-fixes-to-rtc-subsystems-kconfig.patch
rtc-pcf8583-dont-abuse-i2c_m_nostart.patch
pnp-request-ioport-and-iomem-resources-used-by-active-devices.patch
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