Am 08.10.21 um 09:54 schrieb guangming.cao@mediatek.com:

From: Guangming Cao Guangming.Cao@mediatek.com

Because dma-buf.name can be freed in func: "dma_buf_set_name", so, we need to acquire lock first before we read/write dma_buf.name to prevent Use After Free(UAF) issue.

Signed-off-by: Guangming Cao Guangming.Cao@mediatek.com

Reviewed-by: Christian König christian.koenig@amd.com

Going to push that upstream if nobody else objects.

Thanks, Christian.

---

drivers/dma-buf/dma-buf.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 511fe0d217a0..a7f6fd13a635 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1372,6 +1372,8 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) if (ret) goto error_unlock;

• spin_lock(&buf_obj->name_lock);
  

  seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n", buf_obj->size, buf_obj->file->f_flags, buf_obj->file->f_mode,

@@ -1379,6 +1381,7 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) buf_obj->exp_name, file_inode(buf_obj->file)->i_ino, buf_obj->name ?: "");

• spin_unlock(&buf_obj->name_lock);
  

robj = buf_obj->resv; fence = dma_resv_excl_fence(robj);