From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 56C4B3851C09; Tue, 27 Oct 2020 21:21:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 56C4B3851C09 From: "msebor at gmail dot com" To: glibc-bugs@sourceware.org Subject: [Bug build/26779] benign use after realloc at localealias.c:329 Date: Tue, 27 Oct 2020 21:21:10 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: build X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: msebor at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: glibc-bugs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-bugs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Oct 2020 21:21:10 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D26779 --- Comment #2 from Martin Sebor --- Another instance is in argz-insert.c: argz-insert.c: In function =E2=80=98__argz_insert=E2=80=99: argz-insert.c:52:39: warning: dereferencing a freed pointer [-Wuse-after-fr= ee=3D] 52 | before =3D new_argz + (before - *argz); | ^~~~~ argz-insert.c:48:22: note: freed by =E2=80=98realloc=E2=80=99 here 48 | char *new_argz =3D realloc (*argz, new_argz_len); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The code is straightforward: the value of *argz after a successful call to realloc with it as an argument is (strictly speaking) indeterminate. char *new_argz =3D realloc (*argz, new_argz_len); if (new_argz) { before =3D new_argz + (before - *argz); --=20 You are receiving this mail because: You are on the CC list for the bug.=