If the test description is longer than the status alignment the
parameter 'n' to putcharn() would lead to a signed underflow that then
gets converted to a very large unsigned value.
This in turn leads out-of-bound writes in memset() crashing the
application.
The failure case of EXPECT_PTRER() used in "mmap_bad" exhibits this
exact behavior.
Fixes: 8a27526f49f9 ("selftests/nolibc: add EXPECT_PTREQ, EXPECT_PTRNE and EXPECT_PTRER")
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
tools/testing/selftests/nolibc/nolibc-test.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 03b1d30f5507..9b76603e4ce3 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -151,7 +151,8 @@ static void result(int llen, enum RESULT r)
else
msg = "[FAIL]";
- putcharn(' ', 64 - llen);
+ if (llen < 64)
+ putcharn(' ', 64 - llen);
puts(msg);
}
---
base-commit: dfef4fc45d5713eb23d87f0863aff9c33bd4bfaf
change-id: 20230726-nolibc-result-width-1f4b0b4f3ca0
Best regards,
--
Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
