From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tobin C. Harding" Date: Wed, 20 Dec 2017 08:17:16 +1100 Message-Id: <1513718237-24140-3-git-send-email-me@tobin.cc> In-Reply-To: <1513718237-24140-1-git-send-email-me@tobin.cc> References: <1513718237-24140-1-git-send-email-me@tobin.cc> Subject: [kernel-hardening] [PATCH v4 2/3] doc: update kptr_restrict documentation To: Jonathan Corbet Cc: "Tobin C. Harding" , Randy Dunlap , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Kees Cook , Alexander Popov , Joe Perches , kernel-hardening@lists.openwall.com List-ID: Recently the behaviour of printk specifier %pK was changed. The documentation does not currently mirror this. Update documentation for sysctl kptr_restrict. Signed-off-by: Tobin C. Harding --- Documentation/sysctl/kernel.txt | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 63663039acb7..412314eebda6 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -391,7 +391,8 @@ 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), the default, there are no restrictions. +When kptr_restrict is set to 0 (the default) the address is hashed before +printing. (This is the equivalent to %p.) 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 -- 2.7.4