Smatch report warning as follows:
drivers/dma-buf/dma-buf.c:681 dma_buf_export() warn: '&dmabuf->list_node' not removed from list
If dma_buf_stats_setup() fails in dma_buf_export(), goto err_sysfs and dmabuf will be freed, but dmabuf->list_node will not be removed from db_list.head, then list traversal may cause UAF.
Fix by removeing it from db_list.head before free().
Fixes: ef3a6b70507a ("dma-buf: call dma_buf_stats_setup after dmabuf is in valid list") Signed-off-by: Gaosheng Cui cuigaosheng1@huawei.com --- 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 b809513b03fe..6848f50226d5 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -675,6 +675,9 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return dmabuf;
err_sysfs: + mutex_lock(&db_list.lock); + list_del(&dmabuf->list_node); + mutex_unlock(&db_list.lock); /* * Set file->f_path.dentry->d_fsdata to NULL so that when * dma_buf_release() gets invoked by dentry_ops, it exits