From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id B6C0E3858416; Thu, 2 Mar 2023 19:00:35 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B6C0E3858416 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1677783635; bh=igqbcy209tOnPWruSPGwTukXnEx7pCE4QgZhK/qaLDw=; h=From:To:Subject:Date:From; b=T7+QHSBgnOi0S3EPCKX6gcliCvF+QEorYA7BUSqu+U7zVpvGC76qUGFPJJWj0uwCo DPwPB3IDFPeI/JbgDmR6nFe0o16bSWZXymh4XRanXh7gKAd0BYmqM84dO7vnAcJiNf pjTd6LnMo4hBt2ZXNIVr9cGgZtcIgIQUjEZ43GLs= From: "qrzhang at gatech dot edu" To: gcc-bugs@gcc.gnu.org Subject: [Bug sanitizer/108995] New: Missed signed integer overflow checks in UBsan? Date: Thu, 02 Mar 2023 19:00:35 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: sanitizer X-Bugzilla-Version: unknown X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: qrzhang at gatech dot edu X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter cc target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108995 Bug ID: 108995 Summary: Missed signed integer overflow checks in UBsan? Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: sanitizer Assignee: unassigned at gcc dot gnu.org Reporter: qrzhang at gatech dot edu CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org, jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxi= n at gcc dot gnu.org Target Milestone: --- $ cat abc.c int printf(const char *, ...); int a; const int b =3D 44514; int *c =3D &a; void main(void) { *c =3D 65526 * b / 6; printf("%d\n", a); } Ubsan did not emit any message. However, the outputs are different. $ gcc-trunk -O3 -fsanitize=3Dundefined abc.c ; ./a.out -229690488 $ gcc-trunk -fsanitize=3Dundefined abc.c ; ./a.out 486137394=