Re: [PATCH] param: fixup quote parsing of kernel arguments

[Rusty Russell]

Arthur Gautier <ba...@gandi.net> writes:
> When starting kernel with arguments like:
>   init=/bin/sh -c "echo arguments"
> the trailing double quote is not removed which results in following command
> being executed:
>   /bin/sh -c 'echo arguments"'
>
> This commit removes the trailing double quote.
>
> Signed-off-by: Arthur Gautier <ba...@gandi.net>

Hi Arthur,

        Thanks, I'd not considered quotes outside '='.  But this
fixes it in a weird way: we handle quotes below, we just don't do
anything for the "raw value" case:

        for (i = 0; args[i]; i++) {
                if (isspace(args[i]) && !in_quote)
                        break;
                if (equals == 0) {
                        if (args[i] == '=')
                                equals = i;
                }
                if (args[i] == '"')
                        in_quote = !in_quote;
        }

        *param = args;
        if (!equals)
                *val = NULL;
        else {
                args[equals] = '\0';
                *val = args + equals + 1;

                /* Don't include quotes in value. */
                if (**val == '"') {
                        (*val)++;
                        if (args[i-1] == '"')
                                args[i-1] = '\0';
                }
                if (quoted && args[i-1] == '"')
                        args[i-1] = '\0';
        }

The logical fix is to just always remove the close quotes in both
cases:

diff --git a/kernel/params.c b/kernel/params.c
index 728e05b167de..a22d6a759b1a 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -173,9 +173,9 @@ static char *next_arg(char *args, char **param, char **val)
                        if (args[i-1] == '"')
                                args[i-1] = '\0';
                }
-               if (quoted && args[i-1] == '"')
-                       args[i-1] = '\0';
        }
+       if (quoted && args[i-1] == '"')
+               args[i-1] = '\0';
 
        if (args[i]) {
                args[i] = '\0';

Does this work for you?

Thanks,
Rusty.

> ---
>  kernel/params.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/params.c b/kernel/params.c
> index 728e05b..2118546 100644
> --- a/kernel/params.c
> +++ b/kernel/params.c
> @@ -156,8 +156,11 @@ static char *next_arg(char *args, char **param, char 
> **val)
>                       if (args[i] == '=')
>                               equals = i;
>               }
> -             if (args[i] == '"')
> +             if (args[i] == '"') {
> +                     if (!equals)
> +                             args[i] = '\0';
>                       in_quote = !in_quote;
> +             }
>       }
>  
>       *param = args;
> -- 
> 2.1.4
>
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