| Date | Tue, 07 Aug 2012 04:28:38 +0100 | From | Ben Hutchings <> | Subject | [ 43/70] lib/vsprintf.c: kptr_restrict: fix pK-error in SysRq show-all-timers(Q) |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Dan Rosenberg <drosenberg@vsecurity.com>
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 <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> --- lib/vsprintf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -886,7 +886,8 @@ 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);
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