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From: Arvind Sankar <nivedita@alum.mit.edu>
To: "Tobin C . Harding" <me@tobin.cc>, Tycho Andersen <tycho@tycho.ws>
Cc: kernel-hardening@lists.openwall.com,
	Kees Cook <keescook@chromium.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] x86/mm/init: Stop printing pgt_buf addresses
Date: Sat, 29 Feb 2020 18:11:20 -0500
Message-ID: <20200229231120.1147527-1-nivedita@alum.mit.edu> (raw)

This currently leaks kernel physical addresses into userspace.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
 arch/x86/mm/init.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index e7bb483557c9..dc4711f09cdc 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -121,8 +121,6 @@ __ref void *alloc_low_pages(unsigned int num)
 	} else {
 		pfn = pgt_buf_end;
 		pgt_buf_end += num;
-		printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n",
-			pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1);
 	}
 
 	for (i = 0; i < num; i++) {
-- 
2.24.1


             reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-29 23:11 Arvind Sankar [this message]
2020-02-29 23:23 ` Kees Cook
2020-04-09 22:19 ` Arvind Sankar
2020-04-09 22:35   ` Dave Hansen
2020-05-23  1:51 ` Arvind Sankar
2020-05-23  2:57   ` Joe Perches
2020-05-23  7:41 ` [tip: x86/cleanups] x86/mm: Stop printing BRK addresses tip-bot2 for Arvind Sankar

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