Am 22.05.24 um 20:33 schrieb T.J. Mercier:
On Wed, May 22, 2024 at 11:14 AM Fedor Pchelkin <pchel...@ispras.ru> wrote:
kthread creation may possibly fail inside race_signal_callback(). In
such a case stop the already started threads, put the already taken
references to them and return with error code.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 2989f6451084 ("dma-buf: Add selftests for dma-fence")
Cc: sta...@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchel...@ispras.ru>
Reviewed-by: T.J. Mercier <tjmerc...@google.com>
Just FYI: I've picked this one up and pushed it to drm-misc-fixes.
Regards,
Christian.
---
v2: use kthread_stop_put() to actually put the last reference as
T.J. Mercier noticed;
link to v1:
https://lore.kernel.org/lkml/20240522122326.696928-1-pchel...@ispras.ru/
drivers/dma-buf/st-dma-fence.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c
index b7c6f7ea9e0c..6a1bfcd0cc21 100644
--- a/drivers/dma-buf/st-dma-fence.c
+++ b/drivers/dma-buf/st-dma-fence.c
@@ -540,6 +540,12 @@ static int race_signal_callback(void *arg)
t[i].before = pass;
t[i].task = kthread_run(thread_signal_callback, &t[i],
"dma-fence:%d", i);
+ if (IS_ERR(t[i].task)) {
+ ret = PTR_ERR(t[i].task);
+ while (--i >= 0)
+ kthread_stop_put(t[i].task);
+ return ret;
+ }
get_task_struct(t[i].task);
}
--
2.39.2
