[PATCH] erofs-utils: tar: guard empty PAX path trimming

[Vansh Choudhary]

Avoid reading eh->path[j - 1] when a PAX path record carries an
empty value.

Check that j is non-zero before trimming trailing slashes from the
duplicated path buffer.

Signed-off-by: Vansh Choudhary <ch at vnsh.in>
---
 lib/tar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/tar.c b/lib/tar.c
index 77754fd..24e0413 100644
--- a/lib/tar.c
+++ b/lib/tar.c
@@ -517,7 +517,7 @@ int tarerofs_parse_pax_header(struct erofs_iostream *ios,
 				int j = p - 1 - value;
 				free(eh->path);
 				eh->path = strdup(value);
-				while (eh->path[j - 1] == '/')
+				while (j && eh->path[j - 1] == '/')
 					eh->path[--j] = '\0';
 			} else if (!strncmp(kv, "linkpath=",
 					sizeof("linkpath=") - 1)) {
-- 
2.43.0