[LTP] [PATCH v2] tst_kconfig: Avoid reporting buffer overflow when parsing /proc/cmdline

[Li Wang]

 Li Wang <liwang@redhat.com> wrote:

When the test is run with a kernel booting with many parameters, the
> buffer size is often not large enough to store the complete command
> line. This results in a buffer overflow and the test complains with
> the following message:
>
>   tst_kconfig.c:609: TWARN: Buffer overflowed while parsing /proc/cmdline
>
> Note:
>
> Petr point out that these configs, which are generated by toolchain will
> be longer than 128 chars someday, but I don't think that is the reason
> we need raise our parsed buffer, since tst_kcmdline_parse() was just add
> for popular parameter (which always pass by user and short). So far I
> don't see any LTP test parse a longer parameters.
>
> Fixes: 180834982 ("kconfig: add funtion to parse /proc/cmdline")
> Signed-off-by: Li Wang <liwang@redhat.com>
> Cc: Petr Vorel <pvorel@suse.cz>
> ---
>  include/tst_kconfig.h | 2 +-
>  lib/tst_kconfig.c     | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
> index dcb370574..23f807409 100644
> --- a/include/tst_kconfig.h
> +++ b/include/tst_kconfig.h
> @@ -87,7 +87,7 @@ int tst_kconfig_check(const char *const kconfigs[]);
>   */
>  struct tst_kcmdline_var {
>         const char *key;
> -       char value[128];
> +       char value[256];
>         bool found;
>  };
>
> diff --git a/lib/tst_kconfig.c b/lib/tst_kconfig.c
> index e16ca1400..8eb1b803f 100644
> --- a/lib/tst_kconfig.c
> +++ b/lib/tst_kconfig.c
> @@ -569,7 +569,7 @@ char tst_kconfig_get(const char *confname)
>
>  void tst_kcmdline_parse(struct tst_kcmdline_var params[], size_t
> params_len)
>  {
> -       char buf[128], line[512];
> +       char buf[256], line[512];
>

Petr, if you are still worried, feel free to enlarge them to char
'buf[512], line[2048];' during merge :).

BTW, I don't want to allocate the size dynamically to make the code more
complicated.


-- 
Regards,
Li Wang