[Bug] Heap command does not work on 32bit ARM architecture

[dziegel]

GEF+GDB version

GEF 2025.01
SHA256(/opt/pf/data/home/papgft/gef.py): 1b15645a74bd71170093754d0322f4666cb30a73bc95b78daea7c654e1053487
GDB: 13.1
GDB-Python: 3.11

Operating System

Custom debian bookworm, libc 2.36

Describe the issue you encountered

I am debugging a heap issue on a custom debian based linux on an embedded system using a 32 bit ARMv7 processor. GEF does not correctly parse the main arena, because it assumes padding fields to be present which are actually not.

Specifically, the field "("UNUSED_c", ctypes.c_uint32), # padding to align to 0x10" in function "malloc_state_t()" is not present in my 32 bit architecture. Removing this line makes GEF work as expected.

Do you read the docs and look at previously closed issues/PRs for similar cases?

No

Architecture impacted

• X86
• X64
• ARM
• ARM64
• MIPS
• MIPS64
• PPC
• PPC64
• RISCV

Describe your issue. Without a proper reproduction step-by-step, your issue will be ignored.

Start GEF on a 32 bit ARM architecture and issue "heap arenas" command.

Current output on my system (next pointer is invalid):
Arena(base=0xb66157a4, top=0x543b98, last_remainder=0x543af8, next=0x0, mem=421888, mempeak=3059171121)

Output after removing line "("UNUSED_c", ctypes.c_uint32), # padding to align to 0x10" (next pointer is valid now):
Arena(base=0xb66157a4, top=0x571288, last_remainder=0x543b98, next=0xb5a00018, mem=421888, mempeak=421888)
Arena(base=0xb5a00018, top=0xb5a53b40, last_remainder=0xb5a19db0, next=0xb5900018, mem=344064, mempeak=344064)
Arena(base=0xb5900018, top=0xb59c19f8, last_remainder=0xb59ae3c8, next=0xb5b00018, mem=868352, mempeak=868352)
Arena(base=0xb5b00018, top=0xb5b0f298, last_remainder=0xb5b015c0, next=0xb66157a4, mem=135168, mempeak=135168)

Minimalist test case

No response

Additional context?

No response