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lib/vsprintf.c: kptr_restrict: fix pK-error in SysRq show-all-timers(Q)

commit 3715c53 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 <stevie.trujillo@gmail.com>
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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1 parent ffb709e commit 1b772a147a183c09462f0d23e041b077f158fa0f Dan Rosenberg committed with bwhacks Jul 30, 2012
Showing with 2 additions and 1 deletion.
  1. +2 −1 lib/vsprintf.c
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3 lib/vsprintf.c
@@ -886,7 +886,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
* %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);

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