From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Sun, 19 Apr 2026 20:10:10 +0000 (+0200)
Subject: iso9660: Fix ../../ path normalization
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=941e32fd6e37ab7e2441605eebdcd04b9616d60d;p=thirdparty%2Flibarchive.git

iso9660: Fix ../../ path normalization

The function isofile_gen_utility_names could resolve .. directory
entries in a way that dirname will start with "../". If this happens,
the while-loop is unable to detect this because it forwards until the
cursor detects a slash again.

Fix this by also taking "../" at the beginning into account. Such an
entry can happen if "../../" points before the top directory.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/libarchive/archive_write_set_format_iso9660.c b/libarchive/archive_write_set_format_iso9660.c
index 4df9d12a2..1e293588b 100644
--- a/libarchive/archive_write_set_format_iso9660.c
+++ b/libarchive/archive_write_set_format_iso9660.c
@@ -4927,6 +4927,12 @@ isofile_gen_utility_names(struct archive_write *a, struct isofile *file)
 				}
 			} else
 				p++;
+		} else if (p == dirname && p[0] == '.' && p[1] == '.' && p[2] == '/') {
+			size_t off;
+			for (off = 3; p[off] == '/'; off++)
+				;
+			memmove(dirname, p + off, strlen(p + off) + 1);
+			p = dirname;
 		} else
 			p++;
 	}