Bitfield pointers don't render correctly

Open

#8,408 opened on Aug 11, 2026 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 52/100

Issue type: Bug
Clarity: Mostly clear
Activity status: Quiet
Tech stack: cpp
Domain: reverse-engineering

Research direction

Start with StructureMemberLinearViewObject's bitfield-member rendering and compare it with the DataRendererContainer::RenderObjectForData path used by other structure members. Then trace the pointer renderer's handling of bitfield length and the __based pointer; done means the reproduced struct renders foo using its 0x1234 base without consuming bits belonging to bar.

Written by the indexing model from the issue text.

Description

Version and Platform (required):

Binary Ninja Version: based on 5.4.10248
Edition: Ultimate
OS: macOS
OS Version: 26.6
CPU Architecture: arm64

Bug Description:
When a pointer type is rendered as part of a bitfield structure member, the pointer data renderer is not invoked and details like the pointer base is not handled.

Steps To Reproduce:
Please provide all steps required to reproduce the behavior:

Open a new file, enter in bytes 10 00
Create a type with the following signature:

struct struct_1 __packed
{
    void* __ptr16 __based(const, 0x1234) foo : 12;
    int16_t bar : 4;
};

Apply the struct_1 type to the first byte of the binary
Observe the foo member is not rebased as you defined

Expected Behavior:
I expected my pointer base to apply when rendering pointers.

Screenshots/Video Recording:

Additional Information:
This is because StructureMemberLinearViewObject has dedicated behavior for rendering bitfield structure members, and that does not invoke the DataRendererContainer::RenderObjectForData as it does for all other structure members. Even if this were changed, the pointer renderer would need to understand the bitfield length of the member it is rendering, so it does not read the bits shared with other members in the bytes of the rendered member.

Dominant language: C++
Stars: 1.3k
Forks: 298
Avg merge: 4d 13h
Merged PRs (30d): 20

Contributor guide

No contributing guide indexed for this repository

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Similar issues

Use 4:4:4 for multichannel AVIF and HEIF gain maps Open

Difficulty 2/5 1-3 hours Newbie friendliness 70/100

google/libultrahdr#485 · Opened Sep 24, 2026
Missing tile warnings in TileMap dock display with wrong texture filter Open

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

godotengine/godot#123776 · Opened Sep 23, 2026
if(cond,a,b) treats any nonzero cond as true in every bngsim backend (ExprTk interpreter, C codegen, SSA), which contradicts docs/reference/expressions.md ('true when > 0.5') and BNG's run_network. A non-boolean condition in (-inf,0) or... Open

bug

Difficulty 1/5 Under an hour Newbie friendliness 60/100

lanl/bngsim#774 · Opened Sep 23, 2026
Delete ament_export_include_directories() and ament_export_libraries() calls Open

good first issue

Difficulty 1/5 Under an hour Newbie friendliness 90/100

ros2/rosbag2#2509 · Opened Sep 23, 2026
Delete ament_export_include_directories() and ament_export_libraries() calls Open

good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

ros2/common_interfaces#344 · Opened Sep 23, 2026

More C++ issues