Automattic/node-canvas

Segmentation Fault

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#1716 opened on Nov 30, 2020

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BugHelp wanted

Description

I am running pdf.js to convert PDF to PNG. With the attached PDF i'm getting a segmentation fault that seems to be the problem with node-canvas.

Attach (recommended) or Link to PDF file here: Waves-WAVES-Whitepaper-error.pdf

Web browser and its version: Node.js version PDF.js version: tested on 2.6.347 and 2.4.456 Steps to reproduce the problem: Use the node.js pdf2png converter to convert the attached PDF (https://github.com/mozilla/pdf.js/blob/master/examples/node/pdf2png/pdf2png.js)

This will end in a segmentation fault. I installed segfault-handler and ran it again. this is the output.

Is there anybody who can help with this issue. It looks like this might be an issue with node-canvas. Is there another way to get more information on this than the segmentation error log below?

PID 70543 received SIGSEGV for address: 0x0
0   segfault-handler.node               0x0000000102f01010 _ZL16segfault_handleriP9__siginfoPv + 304
1   libsystem_platform.dylib            0x00007fff6d93a5fd _sigtramp + 29
2   ???                                 0x0000ffff00001fa3 0x0 + 281470681751459
3   canvas.node                         0x0000000104c1cc60 _ZN9Context2d4fillEb + 228
4   canvas.node                         0x0000000104c13a3e _ZN9Context2d4FillERKN3Nan20FunctionCallbackInfoIN2v85ValueEEE + 264
5   canvas.node                         0x0000000104c029c8 _ZN3Nan3impL23FunctionCallbackWrapperERKN2v820FunctionCallbackInfoINS1_5ValueEEE + 186
6   node                                0x00000001001f40e8 _ZN2v88internal25FunctionCallbackArguments4CallENS0_15CallHandlerInfoE + 616
7   node                                0x00000001001f36a9 _ZN2v88internal12_GLOBAL__N_119HandleApiCallHelperILb0EEENS0_11MaybeHandleINS0_6ObjectEEEPNS0_7IsolateENS0_6HandleINS0_10HeapObjectEEESA_NS8_INS0_20FunctionTemplateInfoEEENS8_IS4_EENS0_16BuiltinArgumentsE + 521
8   node                                0x00000001001f2dd2 _ZN2v88internalL26Builtin_Impl_HandleApiCallENS0_16BuiltinArgumentsEPNS0_7IsolateE + 258
9   node                                0x000000010097d6b9 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_BuiltinExit + 57

Contributor guide

Tech stack
javascriptcppnodejs
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
5
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
C++node canvas internalsCairo library
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
10
Research direction
The segmentation fault occurs in node canvas's native C++ code, specifically in the Context2d::fill function as shown in the stack trace. To fix this, one must investigate the memory management in the fill operation, likely involving a null pointer dereference. The issue is triggered by a specific PDF file when converting to PNG using pdf.js. Check the node canvas source code at src/Context2d.cc and related files to understand the crash. Reproduce the issue with the attached PDF to isolate the cause. No linked PRs exist, so a fix would need to be developed and tested.