Hi, Cyril Brulebois <k...@debian.org> (2017-11-24): > Raphael Hertzog <hert...@debian.org> (2017-11-24): > > It looks like it has been partially reverted upstream: > > https://bugs.busybox.net/show_bug.cgi?id=10231 > > https://git.busybox.net/busybox/commit/?id=9c143ce52da11ec3d21a3491c3749841d3dc10f0 > > > > However this doesn't work for us either because the changes to "showvars" > > also affect the output of "set" which we are using to retrieve the > > environment variables in env2debconf. > > I think “set” is somewhat broken by this commit. Excerpt of its output: > | initrd='initrd.gz' > | rescue > | vga='788' > > This seems very wrong.
The upstream commit leading to the behavioural change is this one: | commit b6838b520afa8346751577cd7ccbe0b906cd3a52 (HEAD) | Author: Denys Vlasenko <vda.li...@googlemail.com> | Date: Fri Sep 30 11:33:47 2016 +0200 | | ash: [VAR] Sanitise environment variable names on entry (full patch attached) Busybox maintainers: are you OK with a revert until we figure out what to do? (Meaning we can possibly release Buster Alpha 2 without thinking + rewriting things…) KiBi.
From b6838b520afa8346751577cd7ccbe0b906cd3a52 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.li...@googlemail.com>
Date: Fri, 30 Sep 2016 11:33:47 +0200
Subject: [PATCH] ash: [VAR] Sanitise environment variable names on entry
Upstream commit:
Date: Sat, 25 Feb 2012 15:35:18 +0800
[VAR] Sanitise environment variable names on entry
On Tue, Feb 14, 2012 at 10:48:48AM +0000, har...@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 <herb...@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.li...@googlemail.com>
---
shell/ash.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/shell/ash.c b/shell/ash.c
index db943f6c7..59905aa7b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -13119,7 +13119,8 @@ init(void)
initvar();
for (envp = environ; envp && *envp; envp++) {
- if (strchr(*envp, '=')) {
+ p = endofname(*envp);
+ if (p != *envp && *p == '=') {
setvareq(*envp, VEXPORT|VTEXTFIXED);
}
}
--
2.14.0
signature.asc
Description: PGP signature
