From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <sourceware-bugzilla@sourceware.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 1342E3857C51; Sat,  6 Jan 2024 22:26:20 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1342E3857C51
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org;
	s=default; t=1704579980;
	bh=aM0jZCxPacFZ4T8N0sfv39qnts9pG9FfXt+unEdQKKo=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=vRaPTrlRdaMimygzfDhLD+ENaTIQpFIjfaXHcDu1jIKi2KfFhU7jlFgt0qMFdREzv
	 udGqL0OAxBRkIpqPx4TbLI76di+V2LlA0XM+I+pMIACmAYIf3GP4nB822sN8k8aE/n
	 Rx8KXA+KR5yA58eC9g0f7lmiuaCOH87Y37RfMT68=
From: "cvs-commit at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug dynamic-link/31218] PLT rewrite overflows large displacement on
 x32
Date: Sat, 06 Jan 2024 22:26:19 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: glibc
X-Bugzilla-Component: dynamic-link
X-Bugzilla-Version: 2.39
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: NEW
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: <bug-31218-131-9rOi32E7fK@http.sourceware.org/bugzilla/>
In-Reply-To: <bug-31218-131@http.sourceware.org/bugzilla/>
References: <bug-31218-131@http.sourceware.org/bugzilla/>
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
List-Id: <glibc-bugs.sourceware.org>

https://sourceware.org/bugzilla/show_bug.cgi?id=3D31218

--- Comment #2 from Sourceware Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <hjl@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=3Dglibc.git;h=3D0f9afc265a4a0f4ba65=
8d7f71c9602a3fda3538e

commit 0f9afc265a4a0f4ba658d7f71c9602a3fda3538e
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jan 6 14:03:37 2024 -0800

    x32: Handle displacement overflow in PLT rewrite [BZ #31218]

    PLT rewrite calculated displacement with

    ElfW(Addr) disp =3D value - branch_start - JMP32_INSN_SIZE;

    On x32, displacement from 0xf7fbe060 to 0x401030 was calculated as

    unsigned int disp =3D 0x401030 - 0xf7fbe060 - 5;

    with disp =3D=3D 0x8442fcb and caused displacement overflow. The PLT en=
try
    was changed to:

    0xf7fbe060 <+0>:        e9 cb 2f 44 08          jmp    0x401030
    0xf7fbe065 <+5>:        cc                      int3
    0xf7fbe066 <+6>:        cc                      int3
    0xf7fbe067 <+7>:        cc                      int3
    0xf7fbe068 <+8>:        cc                      int3
    0xf7fbe069 <+9>:        cc                      int3
    0xf7fbe06a <+10>:       cc                      int3
    0xf7fbe06b <+11>:       cc                      int3
    0xf7fbe06c <+12>:       cc                      int3
    0xf7fbe06d <+13>:       cc                      int3
    0xf7fbe06e <+14>:       cc                      int3
    0xf7fbe06f <+15>:       cc                      int3

    x32 has 32-bit address range, but it doesn't wrap address around at 4GB,
    JMP target was changed to 0x100401030 (0xf7fbe060LL + 0x8442fcbLL + 5),
    which is above 4GB.

    Always use uint64_t to calculate displacement.  This fixes BZ #31218.
    Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>

--=20
You are receiving this mail because:
You are on the CC list for the bug.=