6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Fedor Pchelkin <pchelkin@xxxxxxxxx>
commit 6cb05d89fd62a76a9b74bd16211fb0930e89fea8 upstream.
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: stable@xxxxxxxxxxxxxxx
Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
Reviewed-by: T.J. Mercier <tjmercier@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522181308.841686-1-pchelkin@xxxxxxxxx
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/dma-buf/st-dma-fence.c | 6 ++++++
1 file changed, 6 insertions(+)
--- 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 *ar
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);
}
