[BProc] beoboot-cm1.9 - bug in modhelper

[Michal J. <mi...@ha...>]

There is a bug in a function show_deps(), modhelper.c, from
beoboot-cm1.9.  The code goes like that:

    while (p && *p) {
        np = strchr(p, ',');
        printf("%.*s", np-p, p)

If there is no comma in a string p then np is set to NULL and
np-p may overflow the second argument to printf which happens to
be int.  When this happens, which is pretty likely on 64-bit platforms,
then printf errors out, returns a negaive value and nothing is printed.
If you wonder I got hit by that. :-)  On x86 you may usually get
away with this.

Here is a fix:

--- beoboot-cm1.9/modhelper.c~	2004-04-19 11:07:31.000000000 -0600
+++ beoboot-cm1.9/modhelper.c	2004-08-10 15:00:13.377034440 -0600
@@ -236,11 +236,13 @@
     p = deps;
     while (p && *p) {
 	np = strchr(p, ',');
-	printf("%.*s", np-p, p);
-	if (np) {
-	    printf(" ");
+	if (np != NULL) {
+	    printf("%.*s ", (int)(np-p), p);
 	    np++;
 	}
+	else {
+	    printf("%s", p);
+	}
 	p = np;
     }
     printf("\n");

OTOH 'modhelper -d' is used in /usr/bin/beoboot script only in
this function:

module_dep() {
    local MODDIR="$1"
    local MOD="$2"
    local DEPS=
    local dep
    DEPS=`module_expand $MODDIR \`$BEOLIB/bin/modhelper -d "$MOD"\``
    for dep in $DEPS; do
        echo "$dep"
        module_dep "$MODDIR" "$dep"
    done
}

which could be simply rewritten as

module_dep() {
    [ -r "$1/modules.dep" ] || depmod
    sed -n 's!'"$2"': *!!p' "$1/modules.dep"
}

making all this recursion unnecessary (and skirting the bug in the
process).

  Michal