Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2] vsprintf: Check real user/group id for %pK | From | Joe Perches <> | Date | Wed, 09 Oct 2013 07:57:56 -0700 |
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On Wed, 2013-10-09 at 07:14 -0400, Dan Rosenberg wrote: > isn't the default value of kptr_restrict 0 now, unless I'm missing > something? If I recall it was 1 when originally written, and then > changed to 0 at some point. Could the documentation be updated to > reflect that?
Yeah, the default got changed by --------------------------- commit 411f05f123cbd7f8aa1edcae86970755a6e2a9d9 Author: Ingo Molnar <mingo@elte.hu> Date: Thu May 12 23:00:28 2011 +0200
kptr_restrict has been triggering bugs in apps such as perf, and it also makes the system less useful by default, so turn it off by default. ---------------------------
Maybe this: --- Documentation/sysctl/kernel.txt | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 9d4c1d1..c17d5ca 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -289,14 +289,15 @@ Default value is "/sbin/hotplug". kptr_restrict: -This toggle indicates whether restrictions are placed on -exposing kernel addresses via /proc and other interfaces. When -kptr_restrict is set to (0), there are no restrictions. When -kptr_restrict is set to (1), the default, kernel pointers -printed using the %pK format specifier will be replaced with 0's -unless the user has CAP_SYSLOG. When kptr_restrict is set to -(2), kernel pointers printed using %pK will be replaced with 0's -regardless of privileges. +This toggle indicates whether restrictions are placed on exposing kernel +addresses via /proc and other interfaces. + +When kptr_restrict is set to (0), the default, there are no restrictions. +When kptr_restrict is set to (1), kernel pointers printed using the %pK +format specifier will be replaced with 0's unless the user has CAP_SYSLOG +and effective user and group ids are equal to the real ids. +When kptr_restrict is set to (2), kernel pointers printed using %pK will +be replaced with 0's regardless of privileges. ==============================================================
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