All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: "Tobin C. Harding" <me@tobin.cc>
Cc: linux-kernel@vger.kernel.org, Eric Biggers <ebiggers3@gmail.com>
Subject: [PATCH] list_debug: Print unmangled addresses
Date: Sun, 1 Apr 2018 15:32:37 -0700	[thread overview]
Message-ID: <20180401223237.GV13332@bombadil.infradead.org> (raw)

From: Matthew Wilcox <mawilcox@microsoft.com>

The entire point of printing the pointers in list_debug is to see if
there's any useful information in them (eg poison values, ASCII, etc);
obscuring them to see if they compare equal makes them much less useful.
If an attacker can force this message to be printed, we've already lost.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

diff --git a/lib/list_debug.c b/lib/list_debug.c
index a34db8d27667..5d5424b51b74 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -21,13 +21,13 @@ bool __list_add_valid(struct list_head *new, struct list_head *prev,
 		      struct list_head *next)
 {
 	if (CHECK_DATA_CORRUPTION(next->prev != prev,
-			"list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
+			"list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
 			prev, next->prev, next) ||
 	    CHECK_DATA_CORRUPTION(prev->next != next,
-			"list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
+			"list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
 			next, prev->next, prev) ||
 	    CHECK_DATA_CORRUPTION(new == prev || new == next,
-			"list_add double add: new=%p, prev=%p, next=%p.\n",
+			"list_add double add: new=%px, prev=%px, next=%px.\n",
 			new, prev, next))
 		return false;
 
@@ -43,16 +43,16 @@ bool __list_del_entry_valid(struct list_head *entry)
 	next = entry->next;
 
 	if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
-			"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
+			"list_del corruption, %px->next is LIST_POISON1 (%px)\n",
 			entry, LIST_POISON1) ||
 	    CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
-			"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
+			"list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
 			entry, LIST_POISON2) ||
 	    CHECK_DATA_CORRUPTION(prev->next != entry,
-			"list_del corruption. prev->next should be %p, but was %p\n",
+			"list_del corruption. prev->next should be %px, but was %px\n",
 			entry, prev->next) ||
 	    CHECK_DATA_CORRUPTION(next->prev != entry,
-			"list_del corruption. next->prev should be %p, but was %p\n",
+			"list_del corruption. next->prev should be %px, but was %px\n",
 			entry, next->prev))
 		return false;
 

             reply	other threads:[~2018-04-01 22:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-01 22:32 Matthew Wilcox [this message]
2018-04-03  3:31 ` [PATCH] list_debug: Print unmangled addresses Tobin C. Harding

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180401223237.GV13332@bombadil.infradead.org \
    --to=willy@infradead.org \
    --cc=ebiggers3@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=me@tobin.cc \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.