David Benjamin 8a7ecd774c util: fix undefined behavior in wl_array_for_each ... If a wl_array has size zero, wl_array_for_each computes NULL + 0 to get to the end pointer. This should be fine, and indeed it would be fine in C++. But the C specification has a mistake here and it is actually undefined behavior. See https://davidben.net/2024/01/15/empty-slices.html Clang's -fsanitize=undefined flags this. I ran into this in Chromium's build with wayland-scanner on one of our XML files. ../../third_party/wayland/src/src/scanner.c:1853:2: runtime error: applying zero offset to null pointer #0 0x55c979b8e02c in emit_code third_party/wayland/src/src/scanner.c:1853:2 #1 0x55c979b89323 in main third_party/wayland/src/src/scanner.c #2 0x7f8dfdb8c6c9 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 #3 0x7f8dfdb8c784 in __libc_start_main csu/../csu/libc-start.c:360:3 #4 0x55c979b70f39 in _start (...) An empty XML file is sufficient to hit this case, so I've added it as a test. To reproduce, undo the fix and include only the test, then build with: CC=clang CFLAGS="-fno-sanitize-recover=undefined" meson build/ -Db_sanitize=undefined -Db_lundef=false ninja -C build test Signed-off-by: David Benjamin <davidben@google.com>		2024-03-24 20:00:01 -04:00
..
data	util: fix undefined behavior in wl_array_for_each	2024-03-24 20:00:01 -04:00
array-test.c
client-test.c	Mitigate UAF crashes due to wl_client_destroy reentrancy	2024-02-23 00:40:32 +00:00
compositor-introspection-test.c
connection-test.c	Do not allow nullable new_id	2022-07-14 08:38:49 -07:00
cpp-compile-test.cpp
display-test.c
event-loop-test.c
exec-fd-leak-checker.c
fixed-test.c
headers-protocol-core-test.c
headers-protocol-test.c
headers-test.c
interface-test.c
list-test.c
map-test.c
meson.build	build: add a gen-scanner-test target	2024-01-15 14:29:10 +01:00
message-test.c	Do not allow nullable new_id	2022-07-14 08:38:49 -07:00
newsignal-test.c
os-wrappers-test.c	tests: manually wrap libc functions	2023-06-27 13:31:50 +02:00
protocol-logger-test.c
proxy-test.c	client: Add method to get display for a given proxy	2023-08-07 13:38:01 +00:00
queue-test.c	client: Allow setting names for queues	2024-01-22 12:34:14 +00:00
resources-test.c	Mitigate UAF crashes due to iteration over freed wl_resources	2024-02-07 09:45:41 +00:00
sanity-test.c	tests: Capture the test client log	2023-02-28 11:22:04 +00:00
scanner-test-gen.sh	util: fix undefined behavior in wl_array_for_each	2024-03-24 20:00:01 -04:00
scanner-test.sh	util: fix undefined behavior in wl_array_for_each	2024-03-24 20:00:01 -04:00
signal-test.c
socket-test.c
test-compositor.c	compat: prefer waitpid() over waitid()	2024-02-21 15:46:41 +00:00
test-compositor.h	tests: Support tests that check for client failure	2023-02-28 11:22:04 +00:00
test-helpers.c	build: fix build and provide compat for OpenBSD	2024-02-21 15:46:41 +00:00
test-runner.c	build: fix build and provide compat for OpenBSD	2024-02-21 15:46:41 +00:00
test-runner.h