Re: [PATCH 066/190] Revert "bpf: Remove unnecessary assertion on fp_old"

[Greg Kroah-Hartman]

On Wed, Apr 21, 2021 at 02:59:01PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit 5bf2fc1f9c88397b125d5ec5f65b1ed9300ba59d.
> 
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes.  The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
> 
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix.  Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
> 
> Cc: Aditya Pakki <pakki001@xxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: https
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  kernel/bpf/core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 75244ecb2389..da29211ea5d8 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -230,6 +230,8 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
>  	struct bpf_prog *fp;
>  	u32 pages;
>  
> +	BUG_ON(fp_old == NULL);
> +
>  	size = round_up(size, PAGE_SIZE);
>  	pages = size / PAGE_SIZE;
>  	if (pages <= fp_old->pages)
> -- 
> 2.31.1
> 

The original commit here is correct, I'll drop this revert.

thanks,

greg k-h