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6l: call dwarfaddfrag when registering D_FILE symbols #142

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Merged
staalmannen merged 1 commit into from
May 22, 2026
Merged

6l: call dwarfaddfrag when registering D_FILE symbols #142

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2 changes: 2 additions & 0 deletions sys/src/cmd/6l/obj.c
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
#define EXTERN
#include "l.h"
#include "../ld/elf.h"
#include "../ld/dwarf.h"
#include <ar.h>

#ifndef DEFAULT
Expand Down Expand Up @@ -854,6 +855,7 @@ ldobj(int f, long c, char *pn)
histgen++;
s->type = SFILE;
s->value = histgen;
dwarfaddfrag(s->value, s->name+1);

@gemini-code-assist gemini-code-assist Bot May 22, 2026

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medium

The call to dwarfaddfrag uses s->name+1 to skip the type prefix (typically 'z' or 'f'). While SFILE symbols in this context are expected to have such a prefix, if s->name were an empty string, this would result in an out-of-bounds read. Adding a check for the string length ensures robustness against malformed object files.

				if(s->name[0] != '\0')
					dwarfaddfrag(s->value, s->name+1);

}
if(histfrogp < MAXHIST) {
histfrog[histfrogp] = s;
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