Bug#1104900: libfile-tail-perl: Use of uninitialized value in numeric eq (==) at /usr/share/perl5/File/Tail.pm line 391.

[Salvatore Bonaccorso]

Source: libfile-tail-perl
Version: 1.3-7
Severity: normal
Tags: upstream patch
Forwarded: https://rt.cpan.org/Ticket/Display.html?id=109163
X-Debbugs-Cc: carnil at debian.org

Hi

Under certain conditiion File::Tail might trigger a

| Use of uninitialized value in numeric eq (==) at /usr/share/perl5/File/Tail.pm line 391.

Upstream seems abandoned since 2015, but the same issue was reported
long time ago as well downstream in Fedora/RedHat (I have no minimal
reproducer available).

Cf. https://bugzilla.redhat.com/show_bug.cgi?id=1283764

They applied a fix for it:

diff -up File-Tail-1.3/Tail.pm.debug.fix File-Tail-1.3/Tail.pm.debug
--- File-Tail-1.3/Tail.pm.debug.fix     2020-11-13 10:54:58.354374382 -0500
+++ File-Tail-1.3/Tail.pm.debug 2020-11-13 10:55:23.809490680 -0500
@@ -382,6 +382,9 @@ sub reset_pointers {
     if (defined($oldhandle)) {
        # If file has not been changed since last OK read do not do anything
        $st=stat($newhandle);
+       # inode 0 should never happen, so this should be safe to init to.
+       $object->{'inode'}=0 unless defined($object->{'inode'});
+       $object->{'curpos'}=0 unless defined($object->{'curpos'});
        # lastread uses fractional time, stat doesn't. This can cause false
         # negatives.
         # If the file was changed the same second as it was last read,
diff -up File-Tail-1.3/Tail.pm.fix File-Tail-1.3/Tail.pm

We could do the same for our packaging.

Regards,
Salvatore