The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 6cb05d89fd62a76a9b74bd16211fb0930e89fea8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024061838-making-gumminess-1815@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

6cb05d89fd62 ("dma-buf: handle testing kthreads creation failure")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6cb05d89fd62a76a9b74bd16211fb0930e89fea8 Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin pchelkin@ispras.ru Date: Wed, 22 May 2024 21:13:08 +0300 Subject: [PATCH] dma-buf: handle testing kthreads creation failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

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@vger.kernel.org Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Reviewed-by: T.J. Mercier tjmercier@google.com Link: https://patchwork.freedesktop.org/patch/msgid/20240522181308.841686-1-pchelk... Signed-off-by: Christian König christian.koenig@amd.com

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); }