[PATCH bpf-next] selftests/bpf: Fix issues in parse_num_list()

[PATCH bpf-next] selftests/bpf: Fix issues in parse_num_list()

[Yuntao Wang]

There are some issues in parse_num_list():

1. The end variable is assigned twice when parsing_end is true.
2. The function does not check that parsing_end should finally be false.

Clean up parse_num_list() and fix these issues.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 tools/testing/selftests/bpf/testing_helpers.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index 795b6798ccee..82f0e2d99c23 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -20,16 +20,16 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 		if (errno)
 			return -errno;
 
-		if (parsing_end)
-			end = num;
-		else
+		if (!parsing_end) {
 			start = num;
+			if (*next == '-') {
+				s = next + 1;
+				parsing_end = true;
+				continue;
+			}
+		}
 
-		if (!parsing_end && *next == '-') {
-			s = next + 1;
-			parsing_end = true;
-			continue;
-		} else if (*next == ',') {
+		if (*next == ',') {
 			parsing_end = false;
 			s = next + 1;
 			end = num;
@@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 			set[i] = true;
 	}
 
-	if (!set)
+	if (!set || parsing_end)
 		return -EINVAL;
 
 	*num_set = set;
-- 
2.35.1

Re: [PATCH bpf-next] selftests/bpf: Fix issues in parse_num_list()

[Andrii Nakryiko]

On Mon, Apr 4, 2022 at 9:45 AM Yuntao Wang <ytcoode@gmail.com> wrote:
>
> There are some issues in parse_num_list():
>
> 1. The end variable is assigned twice when parsing_end is true.
> 2. The function does not check that parsing_end should finally be false.
>
> Clean up parse_num_list() and fix these issues.

It would be great to also explain user-visible bug. What do you do to
trigger bugs? Can you please put that into the commit message, in a
before/after fashion? Thanks!

>
> Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
> ---
>  tools/testing/selftests/bpf/testing_helpers.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
> index 795b6798ccee..82f0e2d99c23 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -20,16 +20,16 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
>                 if (errno)
>                         return -errno;
>
> -               if (parsing_end)
> -                       end = num;
> -               else
> +               if (!parsing_end) {
>                         start = num;
> +                       if (*next == '-') {
> +                               s = next + 1;
> +                               parsing_end = true;
> +                               continue;
> +                       }
> +               }
>
> -               if (!parsing_end && *next == '-') {
> -                       s = next + 1;
> -                       parsing_end = true;
> -                       continue;
> -               } else if (*next == ',') {
> +               if (*next == ',') {
>                         parsing_end = false;
>                         s = next + 1;
>                         end = num;
> @@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
>                         set[i] = true;
>         }
>
> -       if (!set)
> +       if (!set || parsing_end)
>                 return -EINVAL;
>
>         *num_set = set;
> --
> 2.35.1
>

[PATCH bpf-next v2] selftests/bpf: Fix issues in parse_num_list()

[Yuntao Wang]

There are some issues in parse_num_list():

First, the end variable is assigned twice when parsing_end is true, it is
unnecessary.

Second, the function does not check that parsing_end is false after parsing
argument. Thus, if the final part of the argument is something like '4-',
parse_num_list() will discard it instead of returning -EINVAL.

Clean up parse_num_list() and fix these issues.

Before:

 $ ./test_progs -n 2,4-
 #2 atomic_bounds:OK
 Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

After:

 $ ./test_progs -n 2,4-
 Failed to parse test numbers.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
v1 -> v2: add more details to commit message

 tools/testing/selftests/bpf/testing_helpers.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index 795b6798ccee..82f0e2d99c23 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -20,16 +20,16 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 		if (errno)
 			return -errno;
 
-		if (parsing_end)
-			end = num;
-		else
+		if (!parsing_end) {
 			start = num;
+			if (*next == '-') {
+				s = next + 1;
+				parsing_end = true;
+				continue;
+			}
+		}
 
-		if (!parsing_end && *next == '-') {
-			s = next + 1;
-			parsing_end = true;
-			continue;
-		} else if (*next == ',') {
+		if (*next == ',') {
 			parsing_end = false;
 			s = next + 1;
 			end = num;
@@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 			set[i] = true;
 	}
 
-	if (!set)
+	if (!set || parsing_end)
 		return -EINVAL;
 
 	*num_set = set;
-- 
2.35.1

Re: [PATCH bpf-next v2] selftests/bpf: Fix issues in parse_num_list()

[Andrii Nakryiko]

On Mon, Apr 4, 2022 at 11:24 PM Yuntao Wang <ytcoode@gmail.com> wrote:
>
> There are some issues in parse_num_list():
>
> First, the end variable is assigned twice when parsing_end is true, it is
> unnecessary.
>
> Second, the function does not check that parsing_end is false after parsing
> argument. Thus, if the final part of the argument is something like '4-',
> parse_num_list() will discard it instead of returning -EINVAL.
>
> Clean up parse_num_list() and fix these issues.
>
> Before:
>
>  $ ./test_progs -n 2,4-
>  #2 atomic_bounds:OK
>  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>
> After:
>
>  $ ./test_progs -n 2,4-
>  Failed to parse test numbers.
>
> Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
> ---
> v1 -> v2: add more details to commit message
>
>  tools/testing/selftests/bpf/testing_helpers.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
> index 795b6798ccee..82f0e2d99c23 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -20,16 +20,16 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
>                 if (errno)
>                         return -errno;
>
> -               if (parsing_end)
> -                       end = num;
> -               else
> +               if (!parsing_end) {
>                         start = num;
> +                       if (*next == '-') {
> +                               s = next + 1;
> +                               parsing_end = true;
> +                               continue;
> +                       }
> +               }
>
> -               if (!parsing_end && *next == '-') {
> -                       s = next + 1;
> -                       parsing_end = true;
> -                       continue;
> -               } else if (*next == ',') {

I think the new structure of the code is actually harder to follow and
there is no need to change this code in the first place just to
optimize away parsing_end assignmet.

> +               if (*next == ',') {
>                         parsing_end = false;
>                         s = next + 1;
>                         end = num;
> @@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
>                         set[i] = true;
>         }
>
> -       if (!set)
> +       if (!set || parsing_end)
>                 return -EINVAL;
>

this is a real fix, please submit just and drop the first part of the patch

>         *num_set = set;
> --
> 2.35.1
>

[PATCH bpf-next v3] selftests/bpf: Fix issues in parse_num_list()

[Yuntao Wang]

The function does not check that parsing_end is false after parsing
argument. Thus, if the final part of the argument is something like '4-',
which is invalid, parse_num_list() will discard it instead of returning
-EINVAL.

Before:

 $ ./test_progs -n 2,4-
 #2 atomic_bounds:OK
 Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

After:

 $ ./test_progs -n 2,4-
 Failed to parse test numbers.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
v1 -> v2: add more details to commit message
v2 -> v3: remove the first part of the patch

 tools/testing/selftests/bpf/testing_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index 795b6798ccee..87867f7a78c3 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 			set[i] = true;
 	}
 
-	if (!set)
+	if (!set || parsing_end)
 		return -EINVAL;
 
 	*num_set = set;
-- 
2.35.1

Re: [PATCH bpf-next v3] selftests/bpf: Fix issues in parse_num_list()

[patchwork-bot+netdevbpf]

Hello:

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

On Wed,  6 Apr 2022 08:36:22 +0800 you wrote:
> The function does not check that parsing_end is false after parsing
> argument. Thus, if the final part of the argument is something like '4-',
> which is invalid, parse_num_list() will discard it instead of returning
> -EINVAL.
> 
> Before:
> 
> [...]

Here is the summary with links:
  - [bpf-next,v3] selftests/bpf: Fix issues in parse_num_list()
    https://git.kernel.org/bpf/bpf-next/c/958ddfd75d83

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html