From: Gang Yan <yangang@kylinos.cn>
check_transfer() compares the input and output files byte-by-byte using
`cmp -l "$in" "$out" | while read ...`. Because the while-loop body runs
in a subshell (the script sets neither lastpipe nor pipefail), the
fail_test call inside it -- which sets the global ret/last_test_failed --
and the `return 1` both act on the subshell, not on check_transfer().
check_transfer() thus always falls through to `return 0`, and any data
corruption affecting only the payload (leaving the subflow/PM counters
untouched) is silently reported as PASS.
Fixes: 8117dac3e7c3 ("selftests: mptcp: add invert check in check_transfer")
Cc: stable@vger.kernel.org
Assisted-by: Codex:GLM-5.2
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
---
tools/testing/selftests/net/mptcp/mptcp_join.sh | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index c0aeffd5cb71..7dc91fac4917 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -584,7 +584,7 @@ check_transfer()
mv "$tmpfile" "$out"
tmpfile=""
fi
- cmp -l "$in" "$out" | while read -r i a b; do
+ while read -r i a b; do
local sum=$((0${a} + 0${b}))
if [ $check_invert -eq 0 ] || [ $sum -ne $((0xff)) ]; then
fail_test "$what does not match (in, out):"
@@ -595,7 +595,7 @@ check_transfer()
else
print_info "$what has inverted byte at ${i}"
fi
- done
+ done < <(cmp -l "$in" "$out")
return 0
}
--
2.53.0