asm() using the incorrect assembler for amd64 architecture #2509
Description
Test Code
#!/usr/bin/python3
from pwn import asm, context
context(os="linux", arch="amd64", log_level="debug", terminal="kitty")
shellcode = asm(
"""
execve:
lea rdi, [rip+shell]
mov rsi, 0x0
mov rdx, 0x0
mov rax, SYS_execve
syscall
shell:
.string "/bin/sh"
"""
)Debug Output
================================================================================
= Started at 2024-12-24T13:13:56 =
= sys.argv = [ =
= './test.py', =
= ] =
================================================================================
2024-12-24T13:13:56:DEBUG:pwnlib.asm:cpp -C -nostdinc -undef -P -I/usr/lib/python3.13/site-packages/pwnlib/data/includes /dev/stdin
2024-12-24T13:13:56:DEBUG:pwnlib.asm:Assembling
.section .shellcode,"awx"
.global _start
.global __start
_start:
__start:
.intel_syntax noprefix
.p2align 0
execve:
lea rdi, [rip+shell]
mov rsi, 0x0
mov rdx, 0x0
mov rax, 59
syscall
shell:
.string "/bin/sh"
2024-12-24T13:13:56:DEBUG:pwnlib.asm:/usr/bin/i386-elf-as -64 -o /tmp/pwn-asm-eenxda9n/step2 /tmp/pwn-asm-eenxda9n/step1
2024-12-24T13:13:56:ERROR:pwnlib.asm:There was an error running ['/usr/bin/i386-elf-as', '-64', '-o', '/tmp/pwn-asm-eenxda9n/step2', '/tmp/pwn-asm-eenxda9n/step1']:
It had the exitcode 1.
It had this on stdout:
Assembler messages:
Fatal error: no compiled in support for x86_64
2024-12-24T13:13:56:ERROR:pwnlib.asm:An error occurred while assembling:
1: .section .shellcode,"awx"
2: .global _start
3: .global __start
4: _start:
5: __start:
6: .intel_syntax noprefix
7: .p2align 0
8: execve:
9: lea rdi, [rip+shell]
10: mov rsi, 0x0
11: mov rdx, 0x0
12: mov rax, 59
13: syscall
14: shell:
15: .string "/bin/sh"
Traceback (most recent call last):
File "/usr/lib/python3.13/site-packages/pwnlib/asm.py", line 776, in asm
_run(assembler + ['-o', step2, step1])
~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/site-packages/pwnlib/asm.py", line 431, in _run
log.error(msg, *args)
~~~~~~~~~^^^^^^^^^^^^
File "/usr/lib/python3.13/site-packages/pwnlib/log.py", line 439, in error
raise PwnlibException(message % args)
pwnlib.exception.PwnlibException: There was an error running ['/usr/bin/i386-elf-as', '-64', '-o', '/tmp/pwn-asm-eenxda9n/step2', '/tmp/pwn-asm-eenxda9n/step1']:
It had the exitcode 1.
It had this on stdout:
Assembler messages:
Fatal error: no compiled in support for x86_64
Environment
λ ~/ neofetch
-` cub3y0nd@Lux
.o+` ------------
`ooo/ OS: Arch Linux x86_64
`+oooo: Host: ASUS TUF Gaming A15 FA506IV_FA506IV 1.0
`+oooooo: Kernel: 6.12.6-zen1-1-zen
-+oooooo+: Uptime: 2 hours, 43 mins
`/:-:++oooo+: Packages: 1354 (pacman), 10 (flatpak)
`/++++/+++++++: Shell: zsh 5.9
`/++++++++++++++: Resolution: 1920x1080
`/+++ooooooooooooo/` WM: bspwm
./ooosssso++osssssso+` Theme: TokyoNight-zk [GTK2/3]
.oossssso-````/ossssss+` Icons: TokyoNight-SE [GTK2/3]
-osssssso. :ssssssso. Terminal: kitty
:osssssss/ osssso+++. CPU: AMD Ryzen 7 4800H with Radeon Graphics (16) @ 2.900GHz
/ossssssss/ +ssssooo/- GPU: NVIDIA GeForce RTX 2060 Mobile
`/ossssso+/:- -:/+osssso+- GPU: AMD ATI Radeon Vega Series / Radeon Vega Mobile Series
`+sso+:-` `.-/+oso: Memory: 7467MiB / 15401MiB
`++:. `-/+/
.` `/
λ ~/ as --version
GNU assembler (GNU Binutils) 2.43.0
Copyright (C) 2024 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `x86_64-pc-linux-gnu'.
λ ~/ i386-elf-as --version
GNU assembler (GNU Binutils) 2.42
Copyright (C) 2024 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `i386-elf'.
λ ~/ i386-elf-as --help | grep 64
--32/--64/--x32 generate 32bit/64bit/x32 object
default, push, pop, generic32, generic64, i386, i486,
movdiri, movdir64b, avx512_bf16, avx512_vp2intersect,
generic32, generic64, i8086, i186, i286, i386, i486,
-mamd64 accept only AMD64 ISA [default]
-mintel64 accept only Intel64 ISA
λ ~/ i386-elf-as -64
Assembler messages:
Fatal error: no compiled in support for x86_64
λ ~/ python
Python 3.13.1 (main, Dec 4 2024, 18:05:56) [GCC 14.2.1 20240910] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pwn
>>> pwn.version
'4.13.1'
>>>