Commit ef0010a3 authored Nov 29, 2017 by Linus Torvalds

vsprintf: don't use 'restricted_pointer()' when not restricting



Instead, just fall back on the new '%p' behavior which hashes the
pointer.

Otherwise, '%pK' - that was intended to mark a pointer as restricted -
just ends up leaking pointers that a normal '%p' wouldn't leak.  Which
just make the whole thing pointless.

I suspect we should actually get rid of '%pK' entirely, and make it just
work as '%p' regardless, but this is the minimal obvious fix.  People
who actually use 'kptr_restrict' should weigh in on which behavior they
want.

Cc: Tobin Harding <me@tobin.cc>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 668533dc

lib/vsprintf.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1931,6 +1931,8 @@ char pointer(const char fmt, char buf, char end, void *ptr,
		return buf;
		}
		case 'K':
		if (!kptr_restrict)
		break;
		return restricted_pointer(buf, end, ptr, spec);
		case 'N':
		return netdev_bits(buf, end, ptr, fmt);

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