On Mon, Feb 05, 2024 at 12:08:00AM +0000, Mike Beaton wrote: > Good evening. > > Linux kernels from 6.7 upwards (including 6.8rc) appear to have broken > PE section alignment in their EFI stub. > > Up to 6.6, we see monotonically increasing and contiguous VMA and LMA, > as expected for a well-formed PE/COFF file. > > In 6.7 and 6.8 these addresses basically jump around all over the place. > > 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-1925801292 > > objdumps of some example kernels (two good, three bad) follow: > > $ objdump -h vmlinuz-5.15.0-92-generic > > vmlinuz-5.15.0-92-generic: file format pei-x86-64 > > 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+ > > vmlinuz-6.6.11-zabbly+: file format pei-x86-64 > > 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 > > vmlinuz-6.7.3-3-liquorix-amd64: file format pei-x86-64 > > 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+ > > vmlinuz-6.7.3-zabbly+: file format pei-x86-64 > > 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 > > vmlinuz-6.8.0-0.rc3.225.vanilla.fc39.x86_64: file format pei-x86-64 > > 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... -- An old man doll... just what I always wanted! - Clara
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