Sat Jun 10 12:46:32 2023 UTC ()
libarchive: fail if name_max is 0

Add error handling to the USE_READDIR_R code paths that set name_max
from struct statfs or statvfs; if the determined name_max == 0
then return an error.

Avoids a crash in tree_dir_next_posix() when the calculation of
dirent_size from name_max is too small for the memory allocated
for struct dirent.

Submitted to upstream in pull request
	https://github.com/libarchive/libarchive/pull/1903

Should fix PR bin/56080


(lukem)
diff -r1.2 -r1.3 src/external/bsd/libarchive/dist/libarchive/archive_read_disk_posix.c

cvs diff -r1.2 -r1.3 src/external/bsd/libarchive/dist/libarchive/archive_read_disk_posix.c (expand / switch to context diff)
--- src/external/bsd/libarchive/dist/libarchive/archive_read_disk_posix.c 2021/03/29 15:31:46 1.2
+++ src/external/bsd/libarchive/dist/libarchive/archive_read_disk_posix.c 2023/06/10 12:46:32 1.3
@@ -1653,6 +1653,11 @@
 	else
 		t->current_filesystem->name_max = nm;
 #endif
+	if (t->current_filesystem->name_max == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Cannot determine name_max");
+		return (ARCHIVE_FAILED);
+	}
 #endif /* USE_READDIR_R */
 	return (ARCHIVE_OK);
 }
@@ -1726,6 +1731,11 @@
 
 	/* Set maximum filename length. */
 	t->current_filesystem->name_max = sfs.f_namemax;
+	if (t->current_filesystem->name_max == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Cannot determine name_max");
+		return (ARCHIVE_FAILED);
+	}
 	return (ARCHIVE_OK);
 }
 
@@ -1858,6 +1868,11 @@
 #if defined(USE_READDIR_R)
 	/* Set maximum filename length. */
 	t->current_filesystem->name_max = sfs.f_namelen;
+	if (t->current_filesystem->name_max == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Cannot determine name_max");
+		return (ARCHIVE_FAILED);
+	}
 #endif
 	return (ARCHIVE_OK);
 }
@@ -1939,6 +1954,11 @@
 #if defined(USE_READDIR_R)
 	/* Set maximum filename length. */
 	t->current_filesystem->name_max = sfs.f_namemax;
+	if (t->current_filesystem->name_max == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Cannot determine name_max");
+		return (ARCHIVE_FAILED);
+	}
 #endif
 	return (ARCHIVE_OK);
 }
@@ -1993,6 +2013,11 @@
 	else
 		t->current_filesystem->name_max = nm;
 #  endif /* _PC_NAME_MAX */
+	if (t->current_filesystem->name_max == 0) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+		    "Cannot determine name_max");
+		return (ARCHIVE_FAILED);
+	}
 #endif /* USE_READDIR_R */
 	return (ARCHIVE_OK);
 }