From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id EA7B33955404; Tue, 9 Feb 2021 19:41:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org EA7B33955404 From: "antonio.chirizzi at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/99044] New: use-after-free false positive Date: Tue, 09 Feb 2021 19:41:12 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: analyzer X-Bugzilla-Version: 11.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: antonio.chirizzi at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: dmalcolm 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 target_milestone attachments.created 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Feb 2021 19:41:13 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99044 Bug ID: 99044 Summary: use-after-free false positive Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: analyzer Assignee: dmalcolm at gcc dot gnu.org Reporter: antonio.chirizzi at gmail dot com Target Milestone: --- Created attachment 50157 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D50157&action=3Dedit Reproducer for the bug Please find attached the reproducer for this use-after-free which looks a f= alse positive. ls-tree-with-commit.c: In function =E2=80=98oid2strbuf_free=E2=80=99: ls-tree-with-commit.c:53:17: warning: use after =E2=80=98free=E2=80=99 of = =E2=80=98e_strbuf=E2=80=99 [CWE-416] [-Wanalyzer-use-after-free] 53 | strbuf_release(e_strbuf->value); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ =E2=80=98oid2strbuf_free=E2=80=99: events 1-6 | | 51 | while ((e =3D hashmap_iter_next(&iter))) { | | ^ | | | | | (1) following =E2=80=98true=E2=80=99 branch (wh= en =E2=80=98e=E2=80=99 is non-NULL)... | | (4) following =E2=80=98true=E2=80=99 branch (wh= en =E2=80=98e=E2=80=99 is non-NULL)... | 52 | struct oid2strbuf *e_strbuf =3D (struct oid2st= rbuf *)e; | | ~~~~~~~~ | | | | | (2) ...to here | | (5) ...to here | 53 | strbuf_release(e_strbuf->value); | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (6) use after =E2=80=98free=E2=80=99 of =E2=80= =98e_strbuf=E2=80=99; freed at (3) | 54 | free(e_strbuf->value); | 55 | free(e); | | ~~~~~~~ | | | | | (3) freed here use "gcc -fanalyzer -c ls-tree-with-commit.c"=