Re: [devel] [SCM] packages/bash3: heads/p9

["Dmitry V. Levin" <ldv@altlinux.org>]

On Fri, Oct 30, 2020 at 09:35:43PM +0000, Alexey Appolonov wrote:
> Update of /people/alexey/packages/bash3.git
[...]
> commit 0db3057724a11b6e9f3bdca6a831370443aaa06e
> Author: Alexey Appolonov <alexey@altlinux.org>
> Date:   Tue Oct 27 14:36:56 2020 +0300
> 
>     Preventing a segmentation fault in '_evalfile' func of 'evalfile.c'
>     
>     Index 'result' can be -1; The index is checked from the top also
>     (just in case).

Prevent a potential segmentation fault ...

> commit 6c6399d5a7cb51ae53c196f0bfdfd92e43711544
> Author: Alexey Appolonov <alexey@altlinux.org>
> Date:   Tue Oct 27 13:53:08 2020 +0300
> 
>     Preventing a segmentation fault in 'make_redirection' func of 'make_cmd.c'
>     
>     Index 'wlen' is -1 if a length of 'w->word' C-string is 0.

Likewise.

[...]
> diff --git a/bash/builtins/evalfile.c b/bash/builtins/evalfile.c
> index d05bc7b..9eec1a5 100644
> --- a/bash/builtins/evalfile.c
> +++ b/bash/builtins/evalfile.c
> @@ -149,7 +149,8 @@ file_error_and_exit:
>  
>    string = (char *)xmalloc (1 + file_size);
>    result = read (fd, string, file_size);
> -  string[result] = '\0';
> +  if (result >= 0 && result <= file_size)
> +    string[result] = '\0';
>  
>    return_val = errno;
>    close (fd);

Adding a check for result <= file_size?  Really?  Do you suppose that
read (fd, string, file_size) is ever capable of returning a value
greater than file_size?

> diff --git a/bash/make_cmd.c b/bash/make_cmd.c
> index c819b27..bb33da2 100644
> --- a/bash/make_cmd.c
> +++ b/bash/make_cmd.c
> @@ -731,7 +731,12 @@ make_redirection (source, instruction, dest_and_filename)
>      case r_duplicating_output_word:	/* 1>&$foo */
>        w = dest_and_filename.filename;
>        wlen = strlen (w->word) - 1;
> -      if (w->word[wlen] == '-')		/* Yuck */
> +      if (wlen < 0)
> +        {
> +          programming_error (_("make_redirection: redirection instruction `%d' for an empty file name"), instruction);
> +          abort ();
> +        }
> +      else if (w->word[wlen] == '-')	/* Yuck */
>          {
>            w->word[wlen] = '\0';
>  	  if (all_digits (w->word) && legal_number (w->word, &lfd) && lfd == (int)lfd)

A programming error?  Is it ever possible to reach the code added by this hunk?

> @@ -743,7 +748,6 @@ make_redirection (source, instruction, dest_and_filename)
>  	  else
>  	    temp->instruction = (instruction == r_duplicating_input_word) ? r_move_input_word : r_move_output_word;
>          }
> -          
>        break;
>  
>      default:

Do you really need to change spacings in bash3?


-- 
ldv