On Sun, Feb 16, 2014 at 02:13:01PM +0200, Kirill A. Shutemov wrote:

> The patch extends git config --file interface to allow read config from
> stdin.
> 
> Editing stdin or setting value in stdin is an error.
> 
> Include by absolute path is allowed in stdin config, but not by relative
> path.

Thanks, this looks very cleanly done.

One nit:

> diff --git a/config.c b/config.c
> index 6269da907964..7b42608f5c89 100644
> --- a/config.c
> +++ b/config.c
> @@ -443,10 +443,20 @@ static int git_parse_source(config_fn_t fn, void *data)
>               if (get_value(fn, data, var) < 0)
>                       break;
>       }
> -     if (cf->die_on_error)
> -             die("bad config file line %d in %s", cf->linenr, cf->name);
> -     else
> -             return error("bad config file line %d in %s", cf->linenr, 
> cf->name);
> +     if (cf->die_on_error) {
> +             if (cf->name)
> +                     die("bad config file line %d in %s",
> +                                     cf->linenr, cf->name);
> +             else
> +                     die("bad config file line %d", cf->linenr);
> +
> +     } else {
> +             if (cf->name)
> +                     return error("bad config file line %d in %s",
> +                                     cf->linenr, cf->name);
> +             else
> +                     return error("bad config file line %d", cf->linenr);
> +     }

I think I preferred the earlier version where you had "<stdin>" in the
name field, and this hunk could just go away. I know you switched it to
NULL here to avoid making bogus relative filenames in includes.

But that would be pretty straightforward to fix by splitting the "name"
field into an additional "path" field. It looks like "git config --blob"
has the same problem (it will try relative lookups in the filesystem,
even though that is nonsensical from the blob). So we could fix the
existing bug at the same time. :)

Perhaps this could go at the start of your series?

-- >8 --
Subject: config: disallow relative include paths from blobs

When we see a relative config include like:

  [include]
  path = foo

we make it relative to the containing directory of the file
that contains the snippet. This makes no sense for config
read from a blob, as it is not on the filesystem.  Something
like "HEAD:some/path" could have a relative path within the
tree, but:

  1. It would not be part of include.path, which explicitly
     refers to the filesystem.

  2. It would need different parsing rules anyway to
     determine that it is a tree path.

The current code just uses the "name" field, which is wrong.
Let's split that into "name" and "path" fields, use the
latter for relative includes, and fill in only the former
for blobs.

Signed-off-by: Jeff King <p...@peff.net>
---
I don't think we considered includes at all when adding --blob. I cannot
think of any good reason to have even an absolute filesystem include
from a blob. And I wonder if it is possible to cause security mischief
by convincing git to look at /etc/passwd or similar (it would not parse,
of course, but you might be able to glean information from the error
messages or something).

It's probably OK, though, because you would generally not read real
config from an untrusted source (there are many bad things they could
set), and other code which uses the config reader explicitly does not
turn on includes.

 config.c                  | 10 ++++++----
 t/t1305-config-include.sh | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/config.c b/config.c
index d969a5a..b295310 100644
--- a/config.c
+++ b/config.c
@@ -21,6 +21,7 @@ struct config_source {
                } buf;
        } u;
        const char *name;
+       const char *path;
        int die_on_error;
        int linenr;
        int eof;
@@ -97,12 +98,12 @@ static int handle_path_include(const char *path, struct 
config_include_data *inc
        if (!is_absolute_path(path)) {
                char *slash;
 
-               if (!cf || !cf->name)
+               if (!cf || !cf->path)
                        return error("relative config includes must come from 
files");
 
-               slash = find_last_dir_sep(cf->name);
+               slash = find_last_dir_sep(cf->path);
                if (slash)
-                       strbuf_add(&buf, cf->name, slash - cf->name + 1);
+                       strbuf_add(&buf, cf->path, slash - cf->path + 1);
                strbuf_addstr(&buf, path);
                path = buf.buf;
        }
@@ -1040,7 +1041,7 @@ int git_config_from_file(config_fn_t fn, const char 
*filename, void *data)
                struct config_source top;
 
                top.u.file = f;
-               top.name = filename;
+               top.name = top.path = filename;
                top.die_on_error = 1;
                top.do_fgetc = config_file_fgetc;
                top.do_ungetc = config_file_ungetc;
@@ -1062,6 +1063,7 @@ int git_config_from_buf(config_fn_t fn, const char *name, 
const char *buf,
        top.u.buf.len = len;
        top.u.buf.pos = 0;
        top.name = name;
+       top.path = NULL;
        top.die_on_error = 0;
        top.do_fgetc = config_buf_fgetc;
        top.do_ungetc = config_buf_ungetc;
diff --git a/t/t1305-config-include.sh b/t/t1305-config-include.sh
index a707076..6edd38b 100755
--- a/t/t1305-config-include.sh
+++ b/t/t1305-config-include.sh
@@ -122,6 +122,22 @@ test_expect_success 'relative includes from command line 
fail' '
        test_must_fail git -c include.path=one config test.one
 '
 
+test_expect_success 'absolute includes from blobs work' '
+       echo "[test]one = 1" >one &&
+       echo "[include]path=$(pwd)/one" >blob &&
+       blob=$(git hash-object -w blob) &&
+       echo 1 >expect &&
+       git config --blob=$blob test.one >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'relative includes from blobs fail' '
+       echo "[test]one = 1" >one &&
+       echo "[include]path=one" >blob &&
+       blob=$(git hash-object -w blob) &&
+       test_must_fail git config --blob=$blob test.one
+'
+
 test_expect_success 'include cycles are detected' '
        cat >.gitconfig <<-\EOF &&
        [test]value = gitconfig
-- 
1.8.5.2.500.g8060133




--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to