On Mon, May 9, 2022 at 12:50 PM Charan Teja Kalla quic_charante@quicinc.com wrote:

From: Charan Teja Reddy quic_charante@quicinc.com

When dma_buf_stats_setup() fails, it closes the dmabuf file which results into the calling of dma_buf_file_release() where it does list_del(&dmabuf->list_node) with out first adding it to the proper list. This is resulting into panic in the below path: __list_del_entry_valid+0x38/0xac dma_buf_file_release+0x74/0x158 __fput+0xf4/0x428 ____fput+0x14/0x24 task_work_run+0x178/0x24c do_notify_resume+0x194/0x264 work_pending+0xc/0x5f0

Fix it by moving the dma_buf_stats_setup() after dmabuf is added to the list.

Fixes: bdb8d06dfefd ("dmabuf: Add the capability to expose DMA-BUF stats in sysfs") Signed-off-by: Charan Teja Reddy quic_charante@quicinc.com

Tested-by: T.J. Mercier tjmercier@google.com Acked-by: T.J. Mercier tjmercier@google.com

---

drivers/dma-buf/dma-buf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 602b12d..a6fc96e 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -543,10 +543,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) file->f_mode |= FMODE_LSEEK; dmabuf->file = file;

•   ret = dma_buf_stats_setup(dmabuf);
  

•   if (ret)
  

•           goto err_sysfs;
  

•   mutex_init(&dmabuf->lock);
    INIT_LIST_HEAD(&dmabuf->attachments);
  
  

@@ -554,6 +550,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) list_add(&dmabuf->list_node, &db_list.head); mutex_unlock(&db_list.lock);

•   ret = dma_buf_stats_setup(dmabuf);
  

•   if (ret)
  

•           goto err_sysfs;
  

•   return dmabuf;
  
  

err_sysfs:

2.7.4