[PATCH bpf-next v4 1/2] bpftool: Add HELP_SPEC_OPTIONS in token.c

[PATCH bpf-next v4 1/2] bpftool: Add HELP_SPEC_OPTIONS in token.c

[Tao Chen]

$ ./bpftool token help

Usage: bpftool token { show | list }
       bpftool token help
       OPTIONS := { {-j|--json} [{-p|--pretty}] | {-d|--debug} }

Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show")

Acked-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
---
 tools/bpf/bpftool/token.c | 1 +
 1 file changed, 1 insertion(+)

Change list:
 v1 -> v2:
  - strdup(mntent->mnt_opts) once per cmd/map/prog and
    remove another strdrup/free in print_items_per_line
    in patch2.(Alexei)
  v1: https://lore.kernel.org/bpf/20250916054111.1151487-1-chen.dylane@linux.dev
 v2 -> v3:
  - Replace PRINT_DELEGATE_OPT* macros with functions.(Quentin)
  v2: https://lore.kernel.org/bpf/20250917034732.1185429-2-chen.dylane@linux.dev
 v3 -> v4:
  - move the declaration of variable "i" to the top of
    the function.(Quentin)
  - move the declaration of "opts" and "value" inside of
    the for loop.(Quentin)
  v3: https://lore.kernel.org/bpf/20250918120908.1255263-1-chen.dylane@linux.dev

diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c
index 6312e662a12..82b829e44c8 100644
--- a/tools/bpf/bpftool/token.c
+++ b/tools/bpf/bpftool/token.c
@@ -206,6 +206,7 @@ static int do_help(int argc, char **argv)
 	fprintf(stderr,
 		"Usage: %1$s %2$s { show | list }\n"
 		"       %1$s %2$s help\n"
+		"       " HELP_SPEC_OPTIONS " }\n"
 		"\n"
 		"",
 		bin_name, argv[-2]);
-- 
2.48.1

[PATCH bpf-next v4 2/2] bpftool: Fix UAF in get_delegate_value

[Tao Chen]

The return value ret pointer is pointing opts_copy, but opts_copy
gets freed in get_delegate_value before return, fix this by free
the mntent->mnt_opts strdup memory after show delegate value.

Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
---
 tools/bpf/bpftool/token.c | 90 ++++++++++++++++-----------------------
 1 file changed, 37 insertions(+), 53 deletions(-)

diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c
index 82b829e44c8..2bbec4c98f2 100644
--- a/tools/bpf/bpftool/token.c
+++ b/tools/bpf/bpftool/token.c
@@ -20,6 +20,16 @@
 
 #define MOUNTS_FILE "/proc/mounts"
 
+struct {
+	const char *header;
+	const char *key;
+} sets[] = {
+	{"allowed_cmds", "delegate_cmds"},
+	{"allowed_maps", "delegate_maps"},
+	{"allowed_progs", "delegate_progs"},
+	{"allowed_attachs", "delegate_attachs"},
+};
+
 static bool has_delegate_options(const char *mnt_ops)
 {
 	return strstr(mnt_ops, "delegate_cmds") ||
@@ -28,15 +38,14 @@ static bool has_delegate_options(const char *mnt_ops)
 	       strstr(mnt_ops, "delegate_attachs");
 }
 
-static char *get_delegate_value(const char *opts, const char *key)
+static char *get_delegate_value(char *opts, const char *key)
 {
 	char *token, *rest, *ret = NULL;
-	char *opts_copy = strdup(opts);
 
-	if (!opts_copy)
+	if (!opts)
 		return NULL;
 
-	for (token = strtok_r(opts_copy, ",", &rest); token;
+	for (token = strtok_r(opts, ",", &rest); token;
 			token = strtok_r(NULL, ",", &rest)) {
 		if (strncmp(token, key, strlen(key)) == 0 &&
 		    token[strlen(key)] == '=') {
@@ -44,24 +53,19 @@ static char *get_delegate_value(const char *opts, const char *key)
 			break;
 		}
 	}
-	free(opts_copy);
 
 	return ret;
 }
 
-static void print_items_per_line(const char *input, int items_per_line)
+static void print_items_per_line(char *input, int items_per_line)
 {
-	char *str, *rest, *strs;
+	char *str, *rest;
 	int cnt = 0;
 
 	if (!input)
 		return;
 
-	strs = strdup(input);
-	if (!strs)
-		return;
-
-	for (str = strtok_r(strs, ":", &rest); str;
+	for (str = strtok_r(input, ":", &rest); str;
 			str = strtok_r(NULL, ":", &rest)) {
 		if (cnt % items_per_line == 0)
 			printf("\n\t  ");
@@ -69,38 +73,31 @@ static void print_items_per_line(const char *input, int items_per_line)
 		printf("%-20s", str);
 		cnt++;
 	}
-
-	free(strs);
 }
 
 #define ITEMS_PER_LINE 4
 static void show_token_info_plain(struct mntent *mntent)
 {
-	char *value;
+	size_t i;
 
 	printf("token_info  %s", mntent->mnt_dir);
 
-	printf("\n\tallowed_cmds:");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_cmds");
-	print_items_per_line(value, ITEMS_PER_LINE);
-
-	printf("\n\tallowed_maps:");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_maps");
-	print_items_per_line(value, ITEMS_PER_LINE);
+	for (i = 0; i < ARRAY_SIZE(sets); i++) {
+		char *opts, *value;
 
-	printf("\n\tallowed_progs:");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_progs");
-	print_items_per_line(value, ITEMS_PER_LINE);
+		printf("\n\t%s:", sets[i].header);
+		opts = strdup(mntent->mnt_opts);
+		value = get_delegate_value(opts, sets[i].key);
+		print_items_per_line(value, ITEMS_PER_LINE);
+		free(opts);
+	}
 
-	printf("\n\tallowed_attachs:");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_attachs");
-	print_items_per_line(value, ITEMS_PER_LINE);
 	printf("\n");
 }
 
-static void split_json_array_str(const char *input)
+static void split_json_array_str(char *input)
 {
-	char *str, *rest, *strs;
+	char *str, *rest;
 
 	if (!input) {
 		jsonw_start_array(json_wtr);
@@ -108,43 +105,30 @@ static void split_json_array_str(const char *input)
 		return;
 	}
 
-	strs = strdup(input);
-	if (!strs)
-		return;
-
 	jsonw_start_array(json_wtr);
-	for (str = strtok_r(strs, ":", &rest); str;
+	for (str = strtok_r(input, ":", &rest); str;
 			str = strtok_r(NULL, ":", &rest)) {
 		jsonw_string(json_wtr, str);
 	}
 	jsonw_end_array(json_wtr);
-
-	free(strs);
 }
 
 static void show_token_info_json(struct mntent *mntent)
 {
-	char *value;
+	size_t i;
 
 	jsonw_start_object(json_wtr);
-
 	jsonw_string_field(json_wtr, "token_info", mntent->mnt_dir);
 
-	jsonw_name(json_wtr, "allowed_cmds");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_cmds");
-	split_json_array_str(value);
+	for (i = 0; i < ARRAY_SIZE(sets); i++) {
+		char *opts, *value;
 
-	jsonw_name(json_wtr, "allowed_maps");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_maps");
-	split_json_array_str(value);
-
-	jsonw_name(json_wtr, "allowed_progs");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_progs");
-	split_json_array_str(value);
-
-	jsonw_name(json_wtr, "allowed_attachs");
-	value = get_delegate_value(mntent->mnt_opts, "delegate_attachs");
-	split_json_array_str(value);
+		jsonw_name(json_wtr, sets[i].header);
+		opts = strdup(mntent->mnt_opts);
+		value = get_delegate_value(opts, sets[i].key);
+		split_json_array_str(value);
+		free(opts);
+	}
 
 	jsonw_end_object(json_wtr);
 }
-- 
2.48.1

Re: [PATCH bpf-next v4 2/2] bpftool: Fix UAF in get_delegate_value

[Quentin Monnet]

2025-09-19 11:48 UTC+0800 ~ Tao Chen <chen.dylane@linux.dev>
> The return value ret pointer is pointing opts_copy, but opts_copy
> gets freed in get_delegate_value before return, fix this by free
> the mntent->mnt_opts strdup memory after show delegate value.
> 
> Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show")
> Signed-off-by: Tao Chen <chen.dylane@linux.dev>


Reviewed-by: Quentin Monnet <qmo@kernel.org>

Thank you!

Re: [PATCH bpf-next v4 2/2] bpftool: Fix UAF in get_delegate_value

[Andrii Nakryiko]

On Thu, Sep 18, 2025 at 8:48 PM Tao Chen <chen.dylane@linux.dev> wrote:
>
> The return value ret pointer is pointing opts_copy, but opts_copy
> gets freed in get_delegate_value before return, fix this by free
> the mntent->mnt_opts strdup memory after show delegate value.
>
> Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show")
> Signed-off-by: Tao Chen <chen.dylane@linux.dev>
> ---
>  tools/bpf/bpftool/token.c | 90 ++++++++++++++++-----------------------
>  1 file changed, 37 insertions(+), 53 deletions(-)
>
> diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c
> index 82b829e44c8..2bbec4c98f2 100644
> --- a/tools/bpf/bpftool/token.c
> +++ b/tools/bpf/bpftool/token.c
> @@ -20,6 +20,16 @@
>
>  #define MOUNTS_FILE "/proc/mounts"
>
> +struct {

this should have been static, fixed up when applying


> +       const char *header;
> +       const char *key;
> +} sets[] = {
> +       {"allowed_cmds", "delegate_cmds"},
> +       {"allowed_maps", "delegate_maps"},
> +       {"allowed_progs", "delegate_progs"},
> +       {"allowed_attachs", "delegate_attachs"},
> +};
> +
>  static bool has_delegate_options(const char *mnt_ops)
>  {
>         return strstr(mnt_ops, "delegate_cmds") ||

[...]

Re: [PATCH bpf-next v4 1/2] bpftool: Add HELP_SPEC_OPTIONS in token.c

[patchwork-bot+netdevbpf]

Hello:

This series was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <andrii@kernel.org>:

On Fri, 19 Sep 2025 11:48:15 +0800 you wrote:
> $ ./bpftool token help
> 
> Usage: bpftool token { show | list }
>        bpftool token help
>        OPTIONS := { {-j|--json} [{-p|--pretty}] | {-d|--debug} }
> 
> Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show")
> 
> [...]

Here is the summary with links:
  - [bpf-next,v4,1/2] bpftool: Add HELP_SPEC_OPTIONS in token.c
    https://git.kernel.org/bpf/bpf-next/c/bce5749b0201
  - [bpf-next,v4,2/2] bpftool: Fix UAF in get_delegate_value
    (no matching commit)

You are awesome, thank you!
-- 
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