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Date: Mon, 5 Feb 2024 09:06:02 +0700
From: Bagas Sanjaya <bagasdotme@gmail.com>
To: Mike Beaton <mjsbeaton@gmail.com>,
	Linux EFI <linux-efi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>, Ivan Hu <ivan.hu@canonical.com>,
	Jeremy Kerr <jk@ozlabs.org>, Peter Jones <pjones@redhat.com>
Subject: Re: Broken section alignment in 6.7 and 6.8rc EFI stub
Message-ID: <ZcBCiqOroolz1hoh@archie.me>
References: <CAHzAAWQ6srV6LVNdmfbJhOwhBw5ZzxxZZ07aHt9oKkfYAdvuQQ@mail.gmail.com>
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On Mon, Feb 05, 2024 at 12:08:00AM +0000, Mike Beaton wrote:
> Good evening.
>=20
> Linux kernels from 6.7 upwards (including 6.8rc) appear to have broken
> PE section alignment in their EFI stub.
>=20
> Up to 6.6, we see monotonically increasing and contiguous VMA and LMA,
> as  expected for a well-formed PE/COFF file.
>=20
> In 6.7 and 6.8 these addresses basically jump around all over the place.
>=20
> At least one loader which is believed to be enforcing strong but
> reasonable rules on PE section layout refuses to load these:
> https://github.com/acidanthera/bugtracker/issues/2371#issuecomment-192580=
1292
>=20
> objdumps of some example kernels (two good, three bad) follow:
>=20
> $ objdump -h vmlinuz-5.15.0-92-generic
>=20
> vmlinuz-5.15.0-92-generic:     file format pei-x86-64
>=20
> Sections:
> Idx Name          Size      VMA               LMA               File off =
 Algn
>   0 .setup        00003bc0  0000000001000200  0000000001000200  00000200 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   1 .reloc        00000020  0000000001003dc0  0000000001003dc0  00003dc0 =
 2**0
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   2 .compat       00000020  0000000001003de0  0000000001003de0  00003de0 =
 2**0
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   3 .text         00b0f4c0  0000000001003e00  0000000001003e00  00003e00 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
> $ objdump -h vmlinuz-6.6.11-zabbly+
>=20
> vmlinuz-6.6.11-zabbly+:     file format pei-x86-64
>=20
> Sections:
> Idx Name          Size      VMA               LMA               File off =
 Algn
>   0 .setup        00003dc0  0000000001000200  0000000001000200  00000200 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   1 .reloc        00000020  0000000001003fc0  0000000001003fc0  00003fc0 =
 2**0
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   2 .compat       00000020  0000000001003fe0  0000000001003fe0  00003fe0 =
 2**0
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   3 .text         00d6e400  0000000001004000  0000000001004000  00004000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
> $ objdump -h vmlinuz-6.7.3-3-liquorix-amd64
>=20
> vmlinuz-6.7.3-3-liquorix-amd64:     file format pei-x86-64
>=20
> Sections:
> Idx Name          Size      VMA               LMA               File off =
 Algn
>   0 .setup        00003000  0000000000001000  0000000000001000  00001000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   1 .compat       00000008  0000000000c0e000  0000000000c0e000  00004000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   2 .text         00baa000  0000000000005000  0000000000005000  00005000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   3 .data         00001200  0000000000baf000  0000000000baf000  00baf000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, DATA
> $ objdump -h vmlinuz-6.7.3-zabbly+
>=20
> vmlinuz-6.7.3-zabbly+:     file format pei-x86-64
>=20
> Sections:
> Idx Name          Size      VMA               LMA               File off =
 Algn
>   0 .setup        00003000  0000000000001000  0000000000001000  00001000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   1 .compat       00000008  0000000000df0000  0000000000df0000  00004000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   2 .text         00d84000  0000000000005000  0000000000005000  00005000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   3 .data         00001200  0000000000d89000  0000000000d89000  00d89000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, DATA
> $ objdump -h vmlinuz-6.8.0-0.rc3.225.vanilla.fc39.x86_64
>=20
> vmlinuz-6.8.0-0.rc3.225.vanilla.fc39.x86_64:     file format pei-x86-64
>=20
> Sections:
> Idx Name          Size      VMA               LMA               File off =
 Algn
>   0 .setup        00003000  0000000000001000  0000000000001000  00001000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   1 .compat       00000008  0000000000e8b000  0000000000e8b000  00004000 =
 2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   2 .text         00e1f000  0000000000005000  0000000000005000  00005000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   3 .data         00001200  0000000000e24000  0000000000e24000  00e24000 =
 2**4
>                   CONTENTS, ALLOC, LOAD, DATA
> $

So v6.7 onwards misses .reloc section, right?

Confused...

--=20
An old man doll... just what I always wanted! - Clara

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