From 65abd4e92af497bbe1ae1085fa16b1b811a3c652 Mon Sep 17 00:00:00 2001 From: Valentin Date: Sun, 30 Aug 2020 11:13:19 +0200 Subject: Fix undefined behavior Without the casts the bytes accesses get converted to int. but int is not guaranteed to be 4 bytes large. Even when it is 4 bytes large `bytes[3] << 24` does not fit because int is signed. --- xcursor/xcursor.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'xcursor') diff --git a/xcursor/xcursor.c b/xcursor/xcursor.c index aabef483..51ce8323 100644 --- a/xcursor/xcursor.c +++ b/xcursor/xcursor.c @@ -285,11 +285,12 @@ _XcursorReadUInt (XcursorFile *file, XcursorUInt *u) return XcursorFalse; if ((*file->read) (file, bytes, 4) != 4) - return XcursorFalse; - *u = ((bytes[0] << 0) | - (bytes[1] << 8) | - (bytes[2] << 16) | - (bytes[3] << 24)); + return XcursorFalse; + + *u = ((XcursorUInt)(bytes[0]) << 0) | + ((XcursorUInt)(bytes[1]) << 8) | + ((XcursorUInt)(bytes[2]) << 16) | + ((XcursorUInt)(bytes[3]) << 24); return XcursorTrue; } -- cgit v1.2.3