From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stevie Trujillo , Dan Rosenberg , Andrew Morton , Linus Torvalds , Ben Hutchings , Li Zefan Subject: [PATCH 3.4 23/24] lib/vsprintf.c: kptr_restrict: fix pK-error in SysRq show-all-timers(Q) Date: Tue, 18 Feb 2014 14:47:10 -0800 Message-Id: <20140218224550.882493475@linuxfoundation.org> In-Reply-To: <20140218224550.221535225@linuxfoundation.org> References: <20140218224550.221535225@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Rosenberg commit 3715c5309f6d175c3053672b73fd4f73be16fd07 upstream. When using ALT+SysRq+Q all the pointers are replaced with "pK-error" like this: [23153.208033] .base: pK-error with echo h > /proc/sysrq-trigger it works: [23107.776363] .base: ffff88023e60d540 The intent behind this behavior was to return "pK-error" in cases where the %pK format specifier was used in interrupt context, because the CAP_SYSLOG check wouldn't be meaningful. Clearly this should only apply when kptr_restrict is actually enabled though. Reported-by: Stevie Trujillo Signed-off-by: Dan Rosenberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman --- lib/vsprintf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -926,7 +926,8 @@ char *pointer(const char *fmt, char *buf * %pK cannot be used in IRQ context because its test * for CAP_SYSLOG would be meaningless. */ - if (in_irq() || in_serving_softirq() || in_nmi()) { + if (kptr_restrict && (in_irq() || in_serving_softirq() || + in_nmi())) { if (spec.field_width == -1) spec.field_width = 2 * sizeof(void *); return string(buf, end, "pK-error", spec);