cmd/snap-confine: use defensive argument parser #3026
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This switches snap-confine to the far more tested and resilient argument parser. This fixes a possible attack vector where a malicious application would fork/exec snap-confine with especially crafted argument vector. Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
stolowski
approved these changes
Mar 14, 2017
There was a problem hiding this comment.
Looks very nice, readability is much better than the original. One minor nitpick (a general comment rather) - IMHO it would be good to make even simple if-statements such as:
if (cond)
do_something();
into:
if (cond) {
do_something();
}
It just feels good especially for security-sensitive code (but surely in this particular change it's always followed by die(), so no real risks).
Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
niemeyer
requested changes
Mar 14, 2017
cmd/snap-confine/snap-confine.c
Outdated
| return 1; | ||
| } | ||
| // We don't want to handle any other errors, just die if we see one. | ||
| sc_die_on_error(err); |
There was a problem hiding this comment.
This should be something like this instead:
err = sc_parse_args(&argc, &argv, &args);
sc_die_on_error(err);
The usage error may be an actual error inside the respective logic instead of just a code:
error *usage_error = errorf("Usage: snap-confine <security tag> <executable>")
Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
The error message is now sufficiently useful to be passed to sc_die_on_erorr(). This lets us remove the extra conditional code in main. Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
chipaca
approved these changes
May 3, 2017
niemeyer
approved these changes
May 9, 2017
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This switches snap-confine to the far more tested and resilient argument
parser. This fixes a possible attack vector where a malicious
application would fork/exec snap-confine with especially crafted
argument vector.
Signed-off-by: Zygmunt Krynicki zygmunt.krynicki@canonical.com