Re: [PATCH 08/20] tools lib api fs: Fix gcc9 stringop-truncation compilation error

[Petr Mladek]

On Mon 2020-01-06 13:06:53, Arnaldo Carvalho de Melo wrote:
> From: Andrey Zhizhikin <andrey.z@xxxxxxxxx>
> 
> GCC9 introduced string hardening mechanisms, which exhibits the error
> during fs api compilation:
> 
> error: '__builtin_strncpy' specified bound 4096 equals destination size
> [-Werror=stringop-truncation]
> 
> This comes when the length of copy passed to strncpy is is equal to
> destination size, which could potentially lead to buffer overflow.
> 
> There is a need to mitigate this potential issue by limiting the size of
> destination by 1 and explicitly terminate the destination with NULL.
> 
> Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@xxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> Cc: Andrii Nakryiko <andriin@xxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> Cc: Martin KaFai Lau <kafai@xxxxxx>
> Cc: Petr Mladek <pmladek@xxxxxxxx>
> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> Cc: Song Liu <songliubraving@xxxxxx>
> Cc: Yonghong Song <yhs@xxxxxx>
> Cc: bpf@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Link: http://lore.kernel.org/lkml/20191211080109.18765-1-andrey.zhizhikin@xxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Best Regards,
Petr