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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 09:09:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 09:09:54 -0800
commit718c0ddd6aa911fd2a6fb1b6e050fbaee8060e61 (patch)
tree8f502a67605f864773d96dca7c8c6e1a9fa3f322 /drivers/misc
parent8fa3b6f9392bf6d90cb7b908e07bd90166639f0a (diff)
parentaf91a81131aee3e233a977632a23b839857a327b (diff)
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar: "The main RCU changes in this development cycle were: - Miscellaneous fixes, including a change to call_rcu()'s rcu_head alignment check. - Security-motivated list consistency checks, which are disabled by default behind DEBUG_LIST. - Torture-test updates. - Documentation updates, yet again just simple changes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: torture: Prevent jitter from delaying build-only runs torture: Remove obsolete files from rcutorture .gitignore rcu: Don't kick unless grace period or request rcu: Make expedited grace periods recheck dyntick idle state torture: Trace long read-side delays rcu: RCU_TRACE enables event tracing as well as debugfs rcu: Remove obsolete comment from __call_rcu() rcu: Remove obsolete rcu_check_callbacks() header comment rcu: Tighten up __call_rcu() rcu_head alignment check Documentation/RCU: Fix minor typo documentation: Present updated RCU guarantee bug: Avoid Kconfig warning for BUG_ON_DATA_CORRUPTION lib/Kconfig.debug: Fix typo in select statement lkdtm: Add tests for struct list corruption bug: Provide toggle for BUG on data corruption list: Split list_del() debug checking into separate function rculist: Consolidate DEBUG_LIST for list_add_rcu() list: Split list_add() debug checking into separate function
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/lkdtm.h2
-rw-r--r--drivers/misc/lkdtm_bugs.c68
-rw-r--r--drivers/misc/lkdtm_core.c2
3 files changed, 72 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h
index fdf954c2107f..cfa1039c62e7 100644
--- a/drivers/misc/lkdtm.h
+++ b/drivers/misc/lkdtm.h
@@ -21,6 +21,8 @@ void lkdtm_SPINLOCKUP(void);
void lkdtm_HUNG_TASK(void);
void lkdtm_ATOMIC_UNDERFLOW(void);
void lkdtm_ATOMIC_OVERFLOW(void);
+void lkdtm_CORRUPT_LIST_ADD(void);
+void lkdtm_CORRUPT_LIST_DEL(void);
/* lkdtm_heap.c */
void lkdtm_OVERWRITE_ALLOCATION(void);
diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c
index 182ae1894b32..f336206d4b1f 100644
--- a/drivers/misc/lkdtm_bugs.c
+++ b/drivers/misc/lkdtm_bugs.c
@@ -5,8 +5,13 @@
* test source files.
*/
#include "lkdtm.h"
+#include <linux/list.h>
#include <linux/sched.h>
+struct lkdtm_list {
+ struct list_head node;
+};
+
/*
* Make sure our attempts to over run the kernel stack doesn't trigger
* a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
@@ -146,3 +151,66 @@ void lkdtm_ATOMIC_OVERFLOW(void)
pr_info("attempting bad atomic overflow\n");
atomic_inc(&over);
}
+
+void lkdtm_CORRUPT_LIST_ADD(void)
+{
+ /*
+ * Initially, an empty list via LIST_HEAD:
+ * test_head.next = &test_head
+ * test_head.prev = &test_head
+ */
+ LIST_HEAD(test_head);
+ struct lkdtm_list good, bad;
+ void *target[2] = { };
+ void *redirection = &target;
+
+ pr_info("attempting good list addition\n");
+
+ /*
+ * Adding to the list performs these actions:
+ * test_head.next->prev = &good.node
+ * good.node.next = test_head.next
+ * good.node.prev = test_head
+ * test_head.next = good.node
+ */
+ list_add(&good.node, &test_head);
+
+ pr_info("attempting corrupted list addition\n");
+ /*
+ * In simulating this "write what where" primitive, the "what" is
+ * the address of &bad.node, and the "where" is the address held
+ * by "redirection".
+ */
+ test_head.next = redirection;
+ list_add(&bad.node, &test_head);
+
+ if (target[0] == NULL && target[1] == NULL)
+ pr_err("Overwrite did not happen, but no BUG?!\n");
+ else
+ pr_err("list_add() corruption not detected!\n");
+}
+
+void lkdtm_CORRUPT_LIST_DEL(void)
+{
+ LIST_HEAD(test_head);
+ struct lkdtm_list item;
+ void *target[2] = { };
+ void *redirection = &target;
+
+ list_add(&item.node, &test_head);
+
+ pr_info("attempting good list removal\n");
+ list_del(&item.node);
+
+ pr_info("attempting corrupted list removal\n");
+ list_add(&item.node, &test_head);
+
+ /* As with the list_add() test above, this corrupts "next". */
+ item.node.next = redirection;
+ list_del(&item.node);
+
+ if (target[0] == NULL && target[1] == NULL)
+ pr_err("Overwrite did not happen, but no BUG?!\n");
+ else
+ pr_err("list_del() corruption not detected!\n");
+}
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index f9154b8d67f6..7eeb71a75549 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -197,6 +197,8 @@ struct crashtype crashtypes[] = {
CRASHTYPE(EXCEPTION),
CRASHTYPE(LOOP),
CRASHTYPE(OVERFLOW),
+ CRASHTYPE(CORRUPT_LIST_ADD),
+ CRASHTYPE(CORRUPT_LIST_DEL),
CRASHTYPE(CORRUPT_STACK),
CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
CRASHTYPE(OVERWRITE_ALLOCATION),