From: Martin Wilck <martin.wilck@suse.com>
To: "bmarzins@redhat.com" <bmarzins@redhat.com>,
"christophe.varoqui@opensvc.com" <christophe.varoqui@opensvc.com>
Cc: "dm-devel@redhat.com" <dm-devel@redhat.com>
Subject: Re: [dm-devel] [PATCH 3/3] libmutipath: validate the argument count of config strings
Date: Wed, 14 Dec 2022 09:41:50 +0000 [thread overview]
Message-ID: <e4bd27a114e65fc0fcc5b9038d0d216ab9540dd2.camel@suse.com> (raw)
In-Reply-To: <1670974567-8005-4-git-send-email-bmarzins@redhat.com>
On Tue, 2022-12-13 at 17:36 -0600, Benjamin Marzinski wrote:
> The features, path_selector, and hardware_handler config options pass
> their strings directly into the kernel. If users omit the argument
> counts from these strings, or use the wrong value, the kernel's table
> parsing gets completely messed up, and the error messages it prints
> don't reflect what actully went wrong. To avoid messing up the
> kernel table parsing, verify that these strings correctly set the
> argument count to the number of arguments they have.
>
> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
> ---
> libmultipath/dict.c | 110 ++++++++++++++++++++++++++++++++++++++++--
> --
> 1 file changed, 101 insertions(+), 9 deletions(-)
>
> diff --git a/libmultipath/dict.c b/libmultipath/dict.c
> index f4233882..6645de49 100644
> --- a/libmultipath/dict.c
> +++ b/libmultipath/dict.c
> @@ -116,6 +116,58 @@ set_str(vector strvec, void *ptr, const char
> *file, int line_nr)
> return 0;
> }
>
> +static int
> +set_arg_str(vector strvec, void *ptr, int count_idx, const char
> *file,
> + int line_nr)
> +{
> + char **str_ptr = (char **)ptr;
> + char *old_str = *str_ptr;
> + const char *spaces = " \f\n\r\t\v";
Nit: I believe '\n' can't occur in values passed from multipath.conf,
as we don't support multi-line values. Also, should this be "static
const char * const spaces", maybe?
Other than that, this looks good to me.
Regards,
Martin
> + char *p, *end;
> + int idx = -1;
> + long int count = -1;
> +
> + *str_ptr = set_value(strvec);
> + if (!*str_ptr) {
> + free(old_str);
> + return 1;
> + }
> + p = *str_ptr;
> + while (*p != '\0') {
> + p += strspn(p, spaces);
> + if (*p == '\0')
> + break;
> + idx += 1;
> + if (idx == count_idx) {
> + errno = 0;
> + count = strtol(p, &end, 10);
> + if (errno == ERANGE || end == p ||
> + !(isspace(*end) || *end == '\0')) {
> + count = -1;
> + break;
> + }
> + }
> + p += strcspn(p, spaces);
> + }
> + if (count < 0) {
> + condlog(1, "%s line %d, missing argument count for
> %s",
> + file, line_nr, (char*)VECTOR_SLOT(strvec,
> 0));
> + goto fail;
> + }
> + if (count != idx - count_idx) {
> + condlog(1, "%s line %d, invalid argument count for
> %s:, got '%ld' expected '%d'",
> + file, line_nr, (char*)VECTOR_SLOT(strvec, 0),
> count,
> + idx - count_idx);
> + goto fail;
> + }
> + free(old_str);
> + return 0;
> +fail:
> + free(*str_ptr);
> + *str_ptr = old_str;
> + return 0;
> +}
> +
> static int
> set_path(vector strvec, void *ptr, const char *file, int line_nr)
> {
> @@ -288,6 +340,14 @@ def_ ## option ## _handler (struct config *conf,
> vector strvec, \
> return set_int(strvec, &conf->option, minval, maxval, file,
> line_nr); \
> }
>
> +#define declare_def_arg_str_handler(option,
> count_idx) \
> +static
> int \
> +def_ ## option ## _handler (struct config *conf, vector
> strvec, \
> + const char *file, int
> line_nr) \
> +{
> \
> + return set_arg_str(strvec, &conf->option, count_idx, file,
> line_nr); \
> +}
> +
> #define declare_def_snprint(option,
> function) \
> static
> int \
> snprint_def_ ## option (struct config *conf, struct strbuf
> *buff, \
> @@ -340,6 +400,17 @@ hw_ ## option ## _handler (struct config *conf,
> vector strvec, \
> return set_int(strvec, &hwe->option, minval, maxval, file,
> line_nr); \
> }
>
> +#define declare_hw_arg_str_handler(option,
> count_idx) \
> +static
> int \
> +hw_ ## option ## _handler (struct config *conf, vector
> strvec, \
> + const char *file, int
> line_nr) \
> +{
> \
> + struct hwentry * hwe = VECTOR_LAST_SLOT(conf-
> >hwtable); \
> + if
> (!hwe) \
> + return
> 1; \
> + return set_arg_str(strvec, &hwe->option, count_idx, file,
> line_nr); \
> +}
> +
>
> #define declare_hw_snprint(option,
> function) \
> static
> int \
> @@ -371,6 +442,16 @@ ovr_ ## option ## _handler (struct config *conf,
> vector strvec, \
> file, line_nr); \
> }
>
> +#define declare_ovr_arg_str_handler(option,
> count_idx) \
> +static
> int \
> +ovr_ ## option ## _handler (struct config *conf, vector
> strvec, \
> + const char *file, int
> line_nr) \
> +{
> \
> + if (!conf-
> >overrides) \
> + return
> 1; \
> + return set_arg_str(strvec, &conf->overrides->option,
> count_idx, file, line_nr); \
> +}
> +
> #define declare_ovr_snprint(option,
> function) \
> static
> int \
> snprint_ovr_ ## option (struct config *conf, struct strbuf
> *buff, \
> @@ -401,6 +482,17 @@ mp_ ## option ## _handler (struct config *conf,
> vector strvec, \
> return set_int(strvec, &mpe->option, minval, maxval, file,
> line_nr); \
> }
>
> +#define declare_mp_arg_str_handler(option,
> count_idx) \
> +static
> int \
> +mp_ ## option ## _handler (struct config *conf, vector
> strvec, \
> + const char *file, int
> line_nr) \
> +{
> \
> + struct mpentry * mpe = VECTOR_LAST_SLOT(conf-
> >mptable); \
> + if
> (!mpe) \
> + return
> 1; \
> + return set_arg_str(strvec, &mpe->option, count_idx, file,
> line_nr); \
> +}
> +
> #define declare_mp_snprint(option,
> function) \
> static
> int \
> snprint_mp_ ## option (struct config *conf, struct strbuf
> *buff, \
> @@ -584,13 +676,13 @@ snprint_def_marginal_pathgroups(struct config
> *conf, struct strbuf *buff,
> }
>
>
> -declare_def_handler(selector, set_str)
> +declare_def_arg_str_handler(selector, 1)
> declare_def_snprint_defstr(selector, print_str, DEFAULT_SELECTOR)
> -declare_hw_handler(selector, set_str)
> +declare_hw_arg_str_handler(selector, 1)
> declare_hw_snprint(selector, print_str)
> -declare_ovr_handler(selector, set_str)
> +declare_ovr_arg_str_handler(selector, 1)
> declare_ovr_snprint(selector, print_str)
> -declare_mp_handler(selector, set_str)
> +declare_mp_arg_str_handler(selector, 1)
> declare_mp_snprint(selector, print_str)
>
> static int snprint_uid_attrs(struct config *conf, struct strbuf
> *buff,
> @@ -663,13 +755,13 @@ declare_hw_snprint(prio_args, print_str)
> declare_mp_handler(prio_args, set_str)
> declare_mp_snprint(prio_args, print_str)
>
> -declare_def_handler(features, set_str)
> +declare_def_arg_str_handler(features, 0)
> declare_def_snprint_defstr(features, print_str, DEFAULT_FEATURES)
> -declare_ovr_handler(features, set_str)
> +declare_ovr_arg_str_handler(features, 0)
> declare_ovr_snprint(features, print_str)
> -declare_hw_handler(features, set_str)
> +declare_hw_arg_str_handler(features, 0)
> declare_hw_snprint(features, print_str)
> -declare_mp_handler(features, set_str)
> +declare_mp_arg_str_handler(features, 0)
> declare_mp_snprint(features, print_str)
>
> declare_def_handler(checker_name, set_str)
> @@ -1821,7 +1913,7 @@ declare_hw_snprint(revision, print_str)
> declare_hw_handler(bl_product, set_str)
> declare_hw_snprint(bl_product, print_str)
>
> -declare_hw_handler(hwhandler, set_str)
> +declare_hw_arg_str_handler(hwhandler, 0)
> declare_hw_snprint(hwhandler, print_str)
>
> /*
--
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next prev parent reply other threads:[~2022-12-14 9:42 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-13 23:36 [dm-devel] [PATCH 0/3] multipath config fixes Benjamin Marzinski
2022-12-13 23:36 ` [dm-devel] [PATCH 1/3] libmpathutil: simplify set_value Benjamin Marzinski
2022-12-14 9:19 ` Martin Wilck
2022-12-14 15:28 ` Benjamin Marzinski
2022-12-13 23:36 ` [dm-devel] [PATCH 2/3] libmultipath: don't leak memory on invalid strings Benjamin Marzinski
2022-12-14 9:21 ` Martin Wilck
2022-12-13 23:36 ` [dm-devel] [PATCH 3/3] libmutipath: validate the argument count of config strings Benjamin Marzinski
2022-12-14 9:41 ` Martin Wilck [this message]
2022-12-14 16:12 ` Benjamin Marzinski
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