tree ad4680c123ec1e485006418e8d4cc8eacbebbc32
parent 4a84d61a24296b8253b3f8f7c86ee28df53e2f3b
author Herbert Xu <herbert@gondor.apana.org.au> 1330155318 +0800
committer maximilian attems <max@stro.at> 1341218854 +0200

[klibc] [VAR] Sanitise environment variable names on entry

On Tue, Feb 14, 2012 at 10:48:48AM +0000, harald@redhat.com wrote:
>
> "export -p" prints all environment variables, without checking if the
> environment variable is a valid dash variable name.
>
> IMHO, the only valid usecase for "export -p" is to eval the output.
>
> $ eval $(export -p); echo OK
> OK
>
> Without this patch the following test does error out with:
>
> test.py:
> import os
> os.environ["test-test"]="test"
> os.environ["test_test"]="test"
> os.execv("./dash", [ './dash', '-c', 'eval $(export -p); echo OK' ])
>
> $ python test.py
> ./dash: 1: export: test-test: bad variable name
>
> Of course the results can be more evil, if the environment variable
> name is crafted, that it injects valid shell code.

This patch fixes the issue by sanitising all environment variable names
upon entry into the shell.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: maximilian attems <max@stro.at>