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| author |   Matthew Wilcox <mawilcox@microsoft.com> | 2017-03-03 12:16:10 -0500 |
|---|---|---|
| committer | Matthew Wilcox <mawilcox@microsoft.com> | 2017-03-07 13:18:23 -0500 |
| commit | 4ecd9542dbc3e07f3bd3870aac12839f72b47db4 (patch) | |
| tree | 1345c7ca57563006a0355bec1bbe689dd14ca67c /tools/testing/radix-tree/main.c | |
| parent | radix tree test suite: Depend on Makefile and quieten grep (diff) | |
| download | linux-dev-4ecd9542dbc3e07f3bd3870aac12839f72b47db4.tar.xz linux-dev-4ecd9542dbc3e07f3bd3870aac12839f72b47db4.zip | |
ida: Free correct IDA bitmap
There's a relatively rare race where we look at the per-cpu preallocated
IDA bitmap, see it's NULL, allocate a new one, and atomically update it.
If the kmalloc() happened to sleep and we were rescheduled to a different
CPU, or an interrupt came in at the exact right time, another task
might have successfully allocated a bitmap and already deposited it.
I forgot what the semantics of cmpxchg() were and ended up freeing the
wrong bitmap leading to KASAN reporting a use-after-free.
Dmitry found the bug with syzkaller & wrote the patch. I wrote the test
case that will reproduce the bug without his patch being applied.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Diffstat (limited to 'tools/testing/radix-tree/main.c')
| -rw-r--r-- | tools/testing/radix-tree/main.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index b829127d5670..bc9a78449572 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -368,6 +368,7 @@ int main(int argc, char **argv) iteration_test(0, 10 + 90 * long_run); iteration_test(7, 10 + 90 * long_run); single_thread_tests(long_run); + ida_thread_tests(); /* Free any remaining preallocated nodes */ radix_tree_cpu_dead(0); |