On Wed, Oct 07, 2015 at 06:26:02PM +0100, Srinivas Kandagatla wrote: > > > On 07/10/15 18:12, Greg KH wrote: > >On Wed, Oct 07, 2015 at 06:01:03PM +0100, Srinivas Kandagatla wrote: > >> > >> > >>On 07/10/15 17:50, Greg KH wrote: > >>>On Wed, Oct 07, 2015 at 05:35:14PM +0100, Srinivas Kandagatla wrote: > >>>>As required by many providers like at24/at25/mxs-ocotp/qfprom, which would > >>>>want to allow root-only to read/write the nvmem content. > >>>>So making the defaults to be root-only access which can prevent normal > >>>>users from reading the nvmem data. > >>>> > >>>>Signed-off-by: Srinivas Kandagatla <[email protected]> > >>>>--- > >>>> drivers/nvmem/core.c | 4 ++-- > >>>> 1 file changed, 2 insertions(+), 2 deletions(-) > >>>> > >>>>diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c > >>>>index 6fd4e5a..4d2e476 100644 > >>>>--- a/drivers/nvmem/core.c > >>>>+++ b/drivers/nvmem/core.c > >>>>@@ -112,7 +112,7 @@ static ssize_t bin_attr_nvmem_write(struct file > >>>>*filp, struct kobject *kobj, > >>>> static struct bin_attribute bin_attr_rw_nvmem = { > >>>> .attr = { > >>>> .name = "nvmem", > >>>>- .mode = S_IWUSR | S_IRUGO, > >>>>+ .mode = S_IWUSR | S_IRUSR, > >>>> }, > >>>> .read = bin_attr_nvmem_read, > >>>> .write = bin_attr_nvmem_write, > >>>>@@ -136,7 +136,7 @@ static const struct attribute_group > >>>>*nvmem_rw_dev_groups[] = { > >>>> static struct bin_attribute bin_attr_ro_nvmem = { > >>>> .attr = { > >>>> .name = "nvmem", > >>>>- .mode = S_IRUGO, > >>>>+ .mode = S_IRUSR, > >>>> }, > >>>> .read = bin_attr_nvmem_read, > >>>> }; > >>> > >>>How about using BIN_ATTR_RO() and friends instead, that way I _know_ you > >>>got the permissions correct as it's impossible to get them wrong by > >>>using those macros. > >>Yes, that sounds good, but there are no macros for just "S_IRUSR" or > >>"(S_IWUSR | S_IRUSR)" in ./include/linux/sysfs.h > > > >Then that means you are trying to do something "odd" and you shouldn't > >be doing that :) > > > The requirement originally came from a discussion regarding file permissions > set by at24 (drivers/mis/eeprom/at24.c) vs nvmem. > > at24 driver sets the permission of root-only read/write, which is different > to what nvmem sets as default. > > So this patch was primarily make nvmem framework inline with what at24/at25 > does.
Doesn't sound like a good idea, take this time to fix that lapse in security :) greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
