[PATCH 6.12 165/567] ktest.pl: Fix uninitialized var in config-bisect.pl

Greg Kroah-Hartman
2026-01-06T17:23:23Z

From: Steven Rostedt <rostedt@goodmis.org>

commit d3042cbe84a060b4df764eb6c5300bbe20d125ca upstream.

The error path of copying the old config used the wrong variable in the
error message:

$ mkdir /tmp/build
$ ./tools/testing/ktest/config-bisect.pl -b /tmp/build config-good /tmp/config-bad
$ chmod 0 /tmp/build
$ ./tools/testing/ktest/config-bisect.pl -b /tmp/build config-good /tmp/config-bad good
cp /tmp/build//.config config-good.tmp ... [0 seconds] FAILED!
Use of uninitialized value $config in concatenation (.) or string at ./tools/testing/ktest/config-bisect.pl line 744.
failed to copy to config-good.tmp

When it should have shown:

failed to copy /tmp/build//.config to config-good.tmp

Cc: stable@vger.kernel.org
Cc: John 'Warthog9' Hawley <warthog9@kernel.org>
Fixes: 0f0db065999cf ("ktest: Add standalone config-bisect.pl program")
Link: https://patch.msgid.link/20251203180924.6862bd26@gandalf.local.home
Reported-by: "John W. Krahn" <jwkrahn@shaw.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/ktest/config-bisect.pl | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/tools/testing/ktest/config-bisect.pl
+++ b/tools/testing/ktest/config-bisect.pl
@@ -741,9 +741,9 @@ if ($start) {
die "Can not find file $bad\n";
}
if ($val eq "good") {
- run_command "cp $output_config $good" or die "failed to copy $config to $good\n";
+ run_command "cp $output_config $good" or die "failed to copy $output_config to $good\n";
} elsif ($val eq "bad") {
- run_command "cp $output_config $bad" or die "failed to copy $config to $bad\n";
+ run_command "cp $output_config $bad" or die "failed to copy $output_config to $bad\n";
}
}