[PATCH] dma-buf: fix WARNING in dma_buf_vmap

Szymon Wilczek posted 1 patch 1 month, 2 weeks ago
drivers/dma-buf/dma-buf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] dma-buf: fix WARNING in dma_buf_vmap
Posted by Szymon Wilczek 1 month, 2 weeks ago
When a driver's vmap callback returns an error (e.g. -ENOMEM), dma_buf_vmap()
triggers a WARN_ON_ONCE(). This is incorrect as vmap operations can legitimately
fail due to resource exhaustion or other transient conditions, as documented.

Fix this by removing the WARN_ON_ONCE(). The error code is already correctly
propagated to the caller.

Reported-by: syzbot+4317d7108e14e5d56308@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4317d7108e14e5d56308
Signed-off-by: Szymon Wilczek <swilczek.lx@gmail.com>
---
 drivers/dma-buf/dma-buf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index edaa9e4ee4ae..14b55f67ee1c 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1525,7 +1525,7 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
 
 	ret = dmabuf->ops->vmap(dmabuf, &ptr);
-	if (WARN_ON_ONCE(ret))
+	if (ret)
 		return ret;
 
 	dmabuf->vmap_ptr = ptr;
-- 
2.52.0