Re: [PATCH bpf v2] tools: bpftool: fix infinite loop in map create

[Quentin Monnet]

2019-04-12 14:40 UTC+0200 ~ Alban Crequy <alban.crequy@xxxxxxxxx>
> From: Alban Crequy <alban@xxxxxxxxxx>
> 
> "bpftool map create" has an infinite loop on "while (argc)". The error
> case is missing.
> 
> Symptoms: when forgetting to type the keyword 'type' in front of 'hash':
> $ sudo bpftool map create /sys/fs/bpf/dir/foobar hash key 8 value 8 entries 128
> (infinite loop, taking all the CPU)
> ^C
> 
> After the patch:
> $ sudo bpftool map create /sys/fs/bpf/dir/foobar hash key 8 value 8 entries 128
> Error: unknown arg hash
> 
> Fixes: 0b592b5a01be ("tools: bpftool: add map create command")
> Signed-off-by: Alban Crequy <alban@xxxxxxxxxx>
> 
> ---
> 
> Changes in v2:
> - Explain the cause of the bug in commitmsg
> - Add the "fixes" line in the commitmsg (Jakub's review)
> - Rebase on the bpf tree
> 
> v1 was initially based on bpf-next and submitted on
> https://marc.info/?l=linux-kernel&m=155310327709613&w=2
> ---
>  tools/bpf/bpftool/map.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> index 05b029b934a6..1ccc38718458 100644
> --- a/tools/bpf/bpftool/map.c
> +++ b/tools/bpf/bpftool/map.c
> @@ -1151,6 +1151,9 @@ static int do_create(int argc, char **argv)
>  				return -1;
>  			}
>  			NEXT_ARG();
> +		} else {
> +			p_err("unknown arg %s", *argv);
> +			return -1;
>  		}
>  	}
>  
> 

Reviewed-by: Quentin Monnet <quentin.monnet@xxxxxxxxxxxxx>

Thanks Alban!