Re: [PATCH] dma-buf: fix WARNING in dma_buf_vmap
From: syzbot
Date: Sat Dec 20 2025 - 14:22:40 EST
> 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+cd944c467e4d4bc24cf6@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug\?extid\=4317d7108e14e5d56308
> Signed-off-by: Szymon Wilczek <szymonwilczek@xxxxxxx>
> ---
> 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
>
I see the command but can't find the corresponding bug.
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but the HASH does not correspond to any known bug.
Please double check the address.