[gpm]gpm 1.20.0 - bug in vc number detection

Jakub Bogusz qboosh@pld.org.pl
Wed, 15 May 2002 22:27:53 +0200

[note: I am not subscriber of gpm list, so please Cc: to me when you answer]


I've just found a bug in vc detection in Gpm_Open().

In Gpm_Open() (liblow.c) there is:

            || !isdigit(tty[strlen(consolename)-1])) {
            gpm_report(GPM_PR_ERR,"strncmp/isdigit/consolename failed");
            goto err;


Note that consolename[strlen(consolename)] points at char just _after_ 0
in "/dev/tty0" or "/dev/vc/0" string. So tty[strlen(consolename)] points
to \0 if console number fits in one digit, or to second digit of console
number (the first is more common). In the first situation vc==0, so gpm
tries to open /dev/tty0, which can fail if current user doesn't own it.

Fix is simple:

--- gpm-1.20.0/src/liblow.c.orig	Sat Feb 23 16:42:23 2002
+++ gpm-1.20.0/src/liblow.c	Wed May 15 22:08:34 2002
@@ -262,7 +262,7 @@
             goto err;
-         conn->vc=atoi(&tty[strlen(consolename)]);
+         conn->vc=atoi(&tty[strlen(consolename)-1]);
       if (gpm_consolefd == -1)

Jakub Bogusz    http://prioris.mini.pw.edu.pl/~qboosh/
PLD Linux       http://www.pld.org.pl/