From 0460534b532e5518c657c7d6492b9337d975eaa3 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Mon, 7 Sep 2020 16:35:40 +0530 Subject: powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute The newly introduced 'perf_stats' attribute uses the default access mode of 0444, allowing non-root users to access performance stats of an nvdimm and potentially force the kernel into issuing a large number of expensive hypercalls. Since the information exposed by this attribute cannot be cached it is better to ward off access to this attribute from users who don't need to access to these performance statistics. Hence update the access mode of 'perf_stats' attribute to be only readable by root users. Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP") Reported-by: Aneesh Kumar K.V Signed-off-by: Vaibhav Jain Reviewed-by: Ira Weiny Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200907110540.21349-1-vaibhav@linux.ibm.com --- arch/powerpc/platforms/pseries/papr_scm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/platforms/pseries/papr_scm.c') diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index f439f0dfea7d..a88a707a608a 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -822,7 +822,7 @@ free_stats: kfree(stats); return rc ? rc : seq_buf_used(&s); } -DEVICE_ATTR_RO(perf_stats); +DEVICE_ATTR_ADMIN_RO(perf_stats); static ssize_t flags_show(struct device *dev, struct device_attribute *attr, char *buf) -- cgit