[PATCH 5.15 097/102] dma-buf: call dma_buf_stats_setup after dmabuf is in valid list

Greg Kroah-Hartman
2022-05-16T20:23:10Z

From: Charan Teja Reddy <quic_charante@quicinc.com>

commit ef3a6b70507a2add2cd2e01f5eb9b54d561bacb9 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/dma-buf/dma-buf.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -572,10 +572,6 @@ struct dma_buf *dma_buf_export(const str
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);

@@ -583,6 +579,10 @@ struct dma_buf *dma_buf_export(const str
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;