dma-buf: call dma_buf_stats_setup after dmabuf is in valid list

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>
Cc: <stable@vger.kernel.org> # 5.15.x+
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1652125797-2043-1-git-send-email-quic_charante@quicinc.com

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index df23239b04fc219afb77041172ab84788dcb7365..b1e25ae98302746f5f718ac910ebdecb5345cdd5 100644 (file)
--- 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: