From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 8 Jan 2025 16:16:42 +0000 (+0000)
Subject: cli: progressbar: Fix integer underflow
X-Git-Tag: 0.9.30~490
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ebdd674177025c1ff14b6881e6fabfe073f619f6;p=pakfire.git

cli: progressbar: Fix integer underflow

It could happen that we required more space than had and then the
expandable part of the progressbar became negative.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/cli/lib/progressbar.c b/src/cli/lib/progressbar.c
index 54c84ce45..cb534ef9b 100644
--- a/src/cli/lib/progressbar.c
+++ b/src/cli/lib/progressbar.c
@@ -149,7 +149,7 @@ static int cli_progressbar_draw(struct cli_progressbar* p) {
 	if (r)
 		return r;
 
-	unsigned int cols_left = cols - p->num_widgets - 2;
+	int cols_left = cols - p->num_widgets - 2;
 
 	// Count how many widgets we have processed
 	unsigned int widgets = 0;
@@ -169,18 +169,21 @@ static int cli_progressbar_draw(struct cli_progressbar* p) {
 		}
 	}
 
-	// How many expandable widgets are left?
-	int num_expandables = p->num_widgets - widgets;
-
-	// How much space do we allocate to each of them?
-	int width = cols_left / num_expandables;
-
-	// Process all expandable widgets
-	STAILQ_FOREACH(widget, &p->widgets, nodes) {
-		if (widget->expandable) {
-			r = widget->print(p, widget, width, widget->data);
-			if (r < 0)
-				return r;
+	// Print the expendable stuff only if there is space left
+	if (cols_left > 0) {
+		// How many expandable widgets are left?
+		int num_expandables = p->num_widgets - widgets;
+
+		// How much space do we allocate to each of them?
+		int width = cols_left / num_expandables;
+
+		// Process all expandable widgets
+		STAILQ_FOREACH(widget, &p->widgets, nodes) {
+			if (widget->expandable) {
+				r = widget->print(p, widget, width, widget->data);
+				if (r < 0)
+					return r;
+			}
 		}
 	}
 
@@ -350,6 +353,10 @@ static int cli_progressbar_add_percentage(struct cli_progressbar* p) {
 
 static ssize_t cli_progressbar_bar(struct cli_progressbar* p,
 		struct cli_progressbar_widget* widget, unsigned int width, void* data) {
+	// This only works if we have at least one byte to fill
+	if (!width)
+		return -ENOBUFS;
+
 	// Allocate or adjust the buffer
 	widget->buffer = pakfire_realloc(widget->buffer, width + 1);