Commit 68c1f082 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds
Browse files

lib/list_debug.c: print unmangled addresses 

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.

Link: http://lkml.kernel.org/r/20180401223237.GV13332@bombadil.infradead.org


Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: default avatarTobin C. Harding <me@tobin.cc>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 31750600

lib/list_debug.c

+7 −7
Original line number Diff line number Diff line
@@ -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;

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