Re: [PATCH] dma-buf: fix WARNING in dma_buf_vmap

[syzbot]

> 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+cd944c...@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug\?extid\=4317d7108e14e5d56308
> Signed-off-by: Szymon Wilczek <szymon...@gmx.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
>

I see the command but can't find the corresponding bug.
The email is sent to syzbo...@syzkaller.appspotmail.com address
but the HASH does not correspond to any known bug.
Please double check the address.

[Szymon Wilczek]

[syzbot]

> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bug...@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-bugs/20251220192210.399423-1-szymonwilczek%40gmx.com.