From: Martin Matuska <martin@matuska.org>
Date: Tue, 9 Jun 2020 05:06:32 +0000 (+0200)
Subject: Skip hardlinks pointing to itself and issue a warning
X-Git-Tag: v3.5.0~28
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3073af254a317e46ac058de47c05a55276ea14b;p=thirdparty%2Flibarchive.git

Skip hardlinks pointing to itself and issue a warning

Fixes #1381
---

diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c
index 0168d0d41..2f86222ce 100644
--- a/libarchive/archive_write_disk_posix.c
+++ b/libarchive/archive_write_disk_posix.c
@@ -546,6 +546,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
 {
 	struct archive_write_disk *a = (struct archive_write_disk *)_a;
 	struct fixup_entry *fe;
+	const char *linkname;
 	int ret, r;
 
 	archive_check_magic(&a->archive, ARCHIVE_WRITE_DISK_MAGIC,
@@ -590,6 +591,17 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
 	if (ret != ARCHIVE_OK)
 		return (ret);
 
+	/*
+	 * Check if we have a hardlink that points to itself.
+	 */
+	linkname = archive_entry_hardlink(a->entry);
+	if (linkname != NULL && strcmp(a->name, linkname) == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Skipping hardlink pointing to itself: %s",
+		    a->name);
+		return (ARCHIVE_WARN);
+	}
+
 	/*
 	 * Query the umask so we get predictable mode settings.
 	 * This gets done on every call to _write_header in case the