forked from luck/tmp_suning_uos_patched
0cd340dcb0
Similar to the list_add() debug consolidation, this commit consolidates the debug checking performed during CONFIG_DEBUG_LIST into a new __list_del_entry_valid() function, and stops list updates when corruption is found. Refactored from same hardening in PaX and Grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Rik van Riel <riel@redhat.com>
73 lines
1.9 KiB
C
73 lines
1.9 KiB
C
/*
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* Copyright 2006, Red Hat, Inc., Dave Jones
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* Released under the General Public License (GPL).
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*
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* This file contains the linked list validation for DEBUG_LIST.
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*/
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#include <linux/export.h>
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#include <linux/list.h>
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#include <linux/bug.h>
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#include <linux/kernel.h>
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#include <linux/rculist.h>
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/*
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* Check that the data structures for the list manipulations are reasonably
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* valid. Failures here indicate memory corruption (and possibly an exploit
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* attempt).
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*/
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bool __list_add_valid(struct list_head *new, struct list_head *prev,
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struct list_head *next)
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{
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if (unlikely(next->prev != prev)) {
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WARN(1, "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
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prev, next->prev, next);
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return false;
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}
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if (unlikely(prev->next != next)) {
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WARN(1, "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
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next, prev->next, prev);
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return false;
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}
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if (unlikely(new == prev || new == next)) {
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WARN(1, "list_add double add: new=%p, prev=%p, next=%p.\n",
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new, prev, next);
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return false;
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}
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return true;
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}
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EXPORT_SYMBOL(__list_add_valid);
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bool __list_del_entry_valid(struct list_head *entry)
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{
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struct list_head *prev, *next;
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prev = entry->prev;
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next = entry->next;
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if (unlikely(next == LIST_POISON1)) {
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WARN(1, "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
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entry, LIST_POISON1);
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return false;
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}
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if (unlikely(prev == LIST_POISON2)) {
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WARN(1, "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
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entry, LIST_POISON2);
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return false;
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}
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if (unlikely(prev->next != entry)) {
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WARN(1, "list_del corruption. prev->next should be %p, but was %p\n",
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entry, prev->next);
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return false;
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}
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if (unlikely(next->prev != entry)) {
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WARN(1, "list_del corruption. next->prev should be %p, but was %p\n",
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entry, next->prev);
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return false;
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}
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return true;
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}
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EXPORT_SYMBOL(__list_del_entry_valid);
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