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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v3] xen: Strip xen.efi by default
On Fri, 7 Nov 2025 at 07:04, Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> On 06.11.2025 17:32, Frediano Ziglio wrote:
> > On Thu, 6 Nov 2025 at 10:27, Jan Beulich <jbeulich@xxxxxxxx> wrote:
> >>
> >> On 06.11.2025 10:58, Frediano Ziglio wrote:
> >>> On Thu, 6 Nov 2025 at 03:52, Demi Marie Obenour <demiobenour@xxxxxxxxx>
> >>> wrote:
> >>>> Does objdump on the signed file return correct section names?
> >>>
> >>> From objdump -x
> >>>
> >>> Sections:
> >>> Idx Name Size VMA LMA File off
> >>> Algn
> >>> 0 .text 0016c9ae ffff82d040200000 ffff82d040200000 00000320
> >>> 2**4
> >>> CONTENTS, ALLOC, LOAD, READONLY, CODE
> >>> 1 .rodata 0006b9e8 ffff82d040400000 ffff82d040400000 0016cce0
> >>> 2**2
> >>> CONTENTS, ALLOC, LOAD, DATA
> >>> 2 .buildid 00000035 ffff82d04046c000 ffff82d04046c000 001d86e0
> >>> 2**2
> >>> CONTENTS, ALLOC, LOAD, READONLY, DATA
> >>> 3 .init.text 0004d123 ffff82d040600000 ffff82d040600000 001d8720
> >>> 2**2
> >>> CONTENTS, ALLOC, LOAD, READONLY, CODE
> >>> 4 .init.data 0006c9b0 ffff82d040800000 ffff82d040800000 00225860
> >>> 2**2
> >>> CONTENTS, ALLOC, LOAD, DATA
> >>> 5 .data.read_mostly 00028da8 ffff82d040a00000 ffff82d040a00000
> >>> 00292220 2**4
> >>> CONTENTS, ALLOC, LOAD, DATA
> >>> 6 .data 0000feec ffff82d040a29000 ffff82d040a29000 002bafe0
> >>> 2**4
> >>> CONTENTS, ALLOC, LOAD, DATA
> >>> 7 .bss 00223108 ffff82d040a39000 ffff82d040a39000 00000000
> >>> 2**4
> >>> ALLOC
> >>> 8 .reloc 000016b8 ffff82d040c5d000 ffff82d040c5d000 002caee0
> >>> 2**2
> >>> CONTENTS, ALLOC, LOAD, READONLY, DATA
> >>> 9 .sbat 000000a6 ffff82d040c5f000 ffff82d040c5f000 002cc5a0
> >>> 2**2
> >>> CONTENTS, READONLY
> >>>
> >>> Which looks correct.
> >>>
> >>> From hexdump -C I can see close to the end
> >>>
> >>> ...
> >>> 002cc580 30 ae 38 ae 60 ae 00 00 00 80 a3 00 10 00 00 00
> >>> |0.8.`...........|
> >>> 002cc590 a0 ae c0 ae e0 ae 00 00 00 00 00 00 00 00 00 00
> >>> |................|
> >>> 002cc5a0 73 62 61 74 2c 31 2c 53 42 41 54 20 56 65 72 73 |sbat,1,SBAT
> >>> Vers|
> >>> 002cc5b0 69 6f 6e 2c 73 62 61 74 2c 31 2c 68 74 74 70 73
> >>> |ion,sbat,1,https|
> >>> 002cc5c0 3a 2f 2f 67 69 74 68 75 62 2e 63 6f 6d 2f 72 68
> >>> |://github.com/rh|
> >>> 002cc5d0 62 6f 6f 74 2f 73 68 69 6d 2f 62 6c 6f 62 2f 6d
> >>> |boot/shim/blob/m|
> >>> 002cc5e0 61 69 6e 2f 53 42 41 54 2e 6d 64 0a 78 65 6e 2e
> >>> |ain/SBAT.md.xen.|
> >>> 002cc5f0 78 73 2c 31 2c 43 6c 6f 75 64 20 53 6f 66 74 77 |xs,1,Cloud
> >>> Softw|
> >>> 002cc600 61 72 65 20 47 72 6f 75 70 2c 78 65 6e 2c 34 2e |are
> >>> Group,xen,4.|
> >>> 002cc610 32 30 2e 31 2d 37 2e 32 32 2e 67 33 65 30 36 37
> >>> |20.1-7.22.g3e067|
> >>> 002cc620 32 36 62 2e 78 73 39 2c 6d 61 69 6c 74 6f 3a 73
> >>> |26b.xs9,mailto:s|
> >>> 002cc630 65 63 75 72 69 74 79 40 78 65 6e 73 65 72 76 65
> >>> |ecurity@xenserve|
> >>> 002cc640 72 2e 63 6f 6d 0a 00 00 00 00 00 00 00 00 00 00
> >>> |r.com...........|
> >>> 002cc650 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >>> |................|
> >>> 002cc660 2c 00 00 00 2e 69 6e 69 74 2e 74 65 78 74 00 2e
> >>> |,....init.text..|
> >>> 002cc670 69 6e 69 74 2e 64 61 74 61 00 2e 64 61 74 61 2e
> >>> |init.data..data.|
> >>> 002cc680 72 65 61 64 5f 6d 6f 73 74 6c 79 00 00 00 00 00
> >>> |read_mostly.....|
> >>> 002cc690 9e 05 00 00 00 02 02 00 30 82 05 92 06 09 2a 86
> >>> |........0.....*.|
> >>> 002cc6a0 48 86 f7 0d 01 07 02 a0 82 05 83 30 82 05 7f 02
> >>> |H..........0....|
> >>> 002cc6b0 01 01 31 0f 30 0d 06 09 60 86 48 01 65 03 04 02
> >>> |..1.0...`.H.e...|
> >>> 002cc6c0 01 05 00 30 5c 06 0a 2b 06 01 04 01 82 37 02 01
> >>> |...0\..+.....7..|
> >>> 002cc6d0 04 a0 4e 30 4c 30 17 06 0a 2b 06 01 04 01 82 37
> >>> |..N0L0...+.....7|
> >>> 002cc6e0 02 01 0f 30 09 03 01 00 a0 04 a2 02 80 00 30 31
> >>> |...0..........01|
> >>> 002cc6f0 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04
> >>> |0...`.H.e.......|
> >>> 002cc700 20 e2 47 64 f8 e8 7b 62 eb 17 e0 13 0a 0d 93 02 |
> >>> .Gd..{b........|
> >>> 002cc710 7a d8 3b f0 20 a8 ee 3d 49 98 3f de c1 47 de 15 |z.;.
> >>> ..=I.?..G..|
> >>> 002cc720 43 a0 82 03 2c 30 82 03 28 30 82 02 10 a0 03 02
> >>> |C...,0..(0......|
> >>> 002cc730 01 02 02 11 00 8f fc 11 bf 41 54 40 74 89 2c 53
> >>> |.........AT@t.,S|
> >>> 002cc740 a5 78 c1 e8 32 30 0d 06 09 2a 86 48 86 f7 0d 01
> >>> |.x..20...*.H....|
> >>> 002cc750 01 0b 05 00 30 1c 31 1a 30 18 06 03 55 04 03 13
> >>> |....0.1.0...U...|
> >>> 002cc760 11 58 65 6e 53 65 72 76 65 72 20 58 65 6e 20 64 |.XenServer
> >>> Xen d|
> >>> 002cc770 65 76 30 1e 17 0d 32 35 30 33 32 30 31 36 35 35
> >>> |ev0...2503201655|
> >>> 002cc780 30 37 5a 17 0d 33 37 30 31 31 39 30 33 31 34 30
> >>> |07Z..37011903140|
> >>> 002cc790 37 5a 30 1c 31 1a 30 18 06 03 55 04 03 13 11 58
> >>> |7Z0.1.0...U....X|
> >>> 002cc7a0 65 6e 53 65 72 76 65 72 20 58 65 6e 20 64 65 76 |enServer Xen
> >>> dev|
> >>> ...
> >>>
> >>> So, this confirms that the string table is there to support larger
> >>> section names and the signature is there and it's working.
> >>
> >> But is it going to work on all EFI implementations, or merely the one you
> >> tried?
> >
> > Can you be more specific ?
> > The file was tested using dozens of different hardware and under Qemu.
> > Only x64 if it's what you mean.
>
> No, I was referring to the fact that there are distinct EFI implementations,
> which may differ in their loader behavior. But see also Demi's clarification
> on her original remark.
>
> Jan
Demi posted an update on that remark that it was a mistake.
The signature should be applied as the last step resulting in it to be
at the end of the file. This as any following update to the file
(beside updating the checksum or the signature itself) would
invalidate the signature and correctly the firmware would refuse to
load the file if secure boot is enabled.
Frediano
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