From: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
After calling radix_tree_iter_retry(), 'slot' will be set to NULL.
This can cause radix_tree_next_slot() to dereference the NULL pointer.
Add Konstantin Khlebnikov's test to the regression framework.
Reported-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx>
---
tools/testing/radix-tree/Makefile | 2 +-
tools/testing/radix-tree/linux/kernel.h | 1 +
tools/testing/radix-tree/main.c | 1 +
tools/testing/radix-tree/regression.h | 1 +
tools/testing/radix-tree/regression3.c | 86 +++++++++++++++++++++++++++++++++
5 files changed, 90 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/radix-tree/regression3.c
diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index 582c8c6..3698a1a 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -3,7 +3,7 @@ CFLAGS += -I. -g -Wall -D_LGPL_SOURCE
LDFLAGS += -lpthread -lurcu
TARGETS = main
OFILES = main.o radix-tree.o linux.o test.o tag_check.o find_next_bit.o \
- regression1.o regression2.o
+ regression1.o regression2.o regression3.o
targets: $(TARGETS)
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index 27d5fe4..ae013b0 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -13,6 +13,7 @@
#define BUG_ON(expr) assert(!(expr))
#define __init
+#define __must_check
#define panic(expr)
#define printk printf
#define __force
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 6b8a412..0e83cad 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -261,6 +261,7 @@ int main(void)
regression1_test();
regression2_test();
+ regression3_test();
single_thread_tests();
sleep(1);
diff --git a/tools/testing/radix-tree/regression.h b/tools/testing/radix-tree/regression.h
index bb1c2ab..e018c48 100644
--- a/tools/testing/radix-tree/regression.h
+++ b/tools/testing/radix-tree/regression.h
@@ -3,5 +3,6 @@
void regression1_test(void);
void regression2_test(void);
+void regression3_test(void);
#endif
diff --git a/tools/testing/radix-tree/regression3.c b/tools/testing/radix-tree/regression3.c
new file mode 100644
index 0000000..17d3ba5
--- /dev/null
+++ b/tools/testing/radix-tree/regression3.c
@@ -0,0 +1,86 @@
+/*
+ * Regression3
+ * Description:
+ * Helper radix_tree_iter_retry resets next_index to the current index.
+ * In following radix_tree_next_slot current chunk size becomes zero.
+ * This isn't checked and it tries to dereference null pointer in slot.
+ *
+ * Running:
+ * This test should run to completion immediately. The above bug would
+ * cause it to segfault.
+ *
+ * Upstream commit:
+ * Not yet
+ */
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/radix-tree.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "regression.h"
+
+void regression3_test(void)
+{
+ RADIX_TREE(root, GFP_KERNEL);
+ void *ptr = (void *)4ul;
+ struct radix_tree_iter iter;
+ void **slot;
+ bool first;
+
+ printf("running regression test 3 (should take milliseconds)\n");
+
+ radix_tree_insert(&root, 0, ptr);
+ radix_tree_tag_set(&root, 0, 0);
+
+ first = true;
+ radix_tree_for_each_tagged(slot, &root, &iter, 0, 0) {
+// printk("tagged %ld %p\n", iter.index, *slot);
+ if (first) {
+ radix_tree_insert(&root, 1, ptr);
+ radix_tree_tag_set(&root, 1, 0);
+ first = false;
+ }
+ if (radix_tree_deref_retry(*slot)) {
+// printk("retry %ld\n", iter.index);
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
+ }
+ radix_tree_delete(&root, 1);
+
+ first = true;
+ radix_tree_for_each_slot(slot, &root, &iter, 0) {
+// printk("slot %ld %p\n", iter.index, *slot);
+ if (first) {
+ radix_tree_insert(&root, 1, ptr);
+ first = false;
+ }
+ if (radix_tree_deref_retry(*slot)) {
+// printk("retry %ld\n", iter.index);
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
+ }
+ radix_tree_delete(&root, 1);
+
+ first = true;
+ radix_tree_for_each_contig(slot, &root, &iter, 0) {
+// printk("contig %ld %p\n", iter.index, *slot);
+ if (first) {
+ radix_tree_insert(&root, 1, ptr);
+ first = false;
+ }
+ if (radix_tree_deref_retry(*slot)) {
+// printk("retry %ld\n", iter.index);
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
+ }
+
+ radix_tree_delete(&root, 0);
+ radix_tree_delete(&root, 1);
+
+ printf("regression test 3 passed\n");
+}
--
2.7.0.rc3
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