path: root/tree-walk.c
diff options
authorJohannes Schindelin <>2019-09-12 12:54:05 (GMT)
committerJohannes Schindelin <>2019-12-04 12:20:05 (GMT)
commite1d911dd4c7b76a5a8cec0f5c8de15981e34da83 (patch)
treec3e36cceeadde0713a1f154b075ca1176f1b4a8b /tree-walk.c
parent0060fd1511b94c918928fa3708f69a3f33895a4a (diff)
mingw: disallow backslash characters in tree objects' file names
The backslash character is not a valid part of a file name on Windows. Hence it is dangerous to allow writing files that were unpacked from tree objects, when the stored file name contains a backslash character: it will be misinterpreted as directory separator. This not only causes ambiguity when a tree contains a blob `a\b` and a tree `a` that contains a blob `b`, but it also can be used as part of an attack vector to side-step the careful protections against writing into the `.git/` directory during a clone of a maliciously-crafted repository. Let's prevent that, addressing CVE-2019-1354. Note: we guard against backslash characters in tree objects' file names _only_ on Windows (because on other platforms, even on those where NTFS volumes can be mounted, the backslash character is _not_ a directory separator), and _only_ when `core.protectNTFS = true` (because users might need to generate tree objects for other platforms, of course without touching the worktree, e.g. using `git update-index --cacheinfo`). Signed-off-by: Johannes Schindelin <>
Diffstat (limited to 'tree-walk.c')
1 files changed, 6 insertions, 0 deletions
diff --git a/tree-walk.c b/tree-walk.c
index d459fed..54ff959 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -41,6 +41,12 @@ static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned l
strbuf_addstr(err, _("empty filename in tree entry"));
return -1;
+ if (protect_ntfs && strchr(path, '\\')) {
+ strbuf_addf(err, _("filename in tree entry contains backslash: '%s'"), path);
+ return -1;
+ }
len = strlen(path) + 1;
/* Initialize the descriptor entry */