File 0014-mingw-fix-quoting-of-arguments.patch of Package git.9802
From d6713e31505ab7de10c6273f58b12680b3f70061 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 13 Sep 2019 16:32:43 +0200
Subject: [PATCH 14/28] mingw: fix quoting of arguments
We need to be careful to follow proper quoting rules. For example, if an
argument contains spaces, we have to quote them. Double-quotes need to
be escaped. Backslashes need to be escaped, but only if they are
followed by a double-quote character.
We need to be _extra_ careful to consider the case where an argument
ends in a backslash _and_ needs to be quoted: in this case, we append a
double-quote character, i.e. the backslash now has to be escaped!
The current code, however, fails to recognize that, and therefore can
turn an argument that ends in a single backslash into a quoted argument
that now ends in an escaped double-quote character. This allows
subsequent command-line parameters to be split and part of them being
mistaken for command-line options, e.g. through a maliciously-crafted
submodule URL during a recursive clone.
Technically, we would not need to quote _all_ arguments which end in a
backslash _unless_ the argument needs to be quoted anyway. For example,
`test\` would not need to be quoted, while `test \` would need to be.
To keep the code simple, however, and therefore easier to reason about
and ensure its correctness, we now _always_ quote an argument that ends
in a backslash.
This addresses CVE-2019-1350.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
compat/mingw.c | 9 ++++++---
t/t7416-submodule-dash-url.sh | 14 ++++++++++++++
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c
index 2d44d21aca..fa61f20e83 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -872,7 +872,7 @@ static const char *quote_arg(const char *arg)
p++;
len++;
}
- if (*p == '"')
+ if (*p == '"' || !*p)
n += count*2 + 1;
continue;
}
@@ -894,16 +894,19 @@ static const char *quote_arg(const char *arg)
count++;
*d++ = *arg++;
}
- if (*arg == '"') {
+ if (*arg == '"' || !*arg) {
while (count-- > 0)
*d++ = '\\';
+ /* don't escape the surrounding end quote */
+ if (!*arg)
+ break;
*d++ = '\\';
}
}
*d++ = *arg++;
}
*d++ = '"';
- *d++ = 0;
+ *d++ = '\0';
return q;
}
diff --git a/t/t7416-submodule-dash-url.sh b/t/t7416-submodule-dash-url.sh
index 459193c976..2966e93071 100755
--- a/t/t7416-submodule-dash-url.sh
+++ b/t/t7416-submodule-dash-url.sh
@@ -31,4 +31,18 @@ test_expect_success 'clone rejects unprotected dash' '
test_i18ngrep ignoring err
'
+test_expect_success 'trailing backslash is handled correctly' '
+ git init testmodule &&
+ test_commit -C testmodule c &&
+ git submodule add ./testmodule &&
+ : ensure that the name ends in a double backslash &&
+ sed -e "s|\\(submodule \"testmodule\\)\"|\\1\\\\\\\\\"|" \
+ -e "s|url = .*|url = \" --should-not-be-an-option\"|" \
+ <.gitmodules >.new &&
+ mv .new .gitmodules &&
+ git commit -am "Add testmodule" &&
+ test_must_fail git clone --verbose --recurse-submodules . dolly 2>err &&
+ test_i18ngrep ! "unknown option" err
+'
+
test_done
--
2.24.0
