engine: common: mod_studio: fix model traversal and crash in Mod_StudioComputeBounds

Mod_StudioComputeBounds incorrectly assumed that all models across all body parts were laid out contiguously in memory. This caused out-of-bounds reads or reading garbage data when loading complex models, leading to crashes.
This commit is contained in:
Владислав Сухов
2026-04-23 18:24:03 +00:00
committed by a1batross
parent 95548053eb
commit 480f29e96e

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@@ -690,7 +690,6 @@ static void Mod_StudioComputeBounds( void *buffer, vec3_t mins, vec3_t maxs, qbo
vec3_t bone_mins, bone_maxs;
vec3_t vert_mins, vert_maxs;
int vert_count, bone_count;
int bodyCount = 0;
vec3_t pos, *pverts;
vert_count = bone_count = 0;
@@ -706,18 +705,16 @@ static void Mod_StudioComputeBounds( void *buffer, vec3_t mins, vec3_t maxs, qbo
// each body part has nummodels variations so there are as many total variations as there
// are in a matrix of each part by each other part
for( i = 0; i < pstudiohdr->numbodyparts; i++ )
bodyCount += pbodypart[i].nummodels;
// The studio models we want are vec3_t mins, vec3_t maxsight after the bodyparts (still need to
// find a detailed breakdown of the mdl format). Move pointer there.
m_pSubModel = (mstudiomodel_t *)(&pbodypart[pstudiohdr->numbodyparts]);
for( i = 0; i < bodyCount; i++ )
{
pverts = (vec3_t *)((byte *)pstudiohdr + m_pSubModel[i].vertindex);
m_pSubModel = (mstudiomodel_t *)((byte *)pstudiohdr + pbodypart[i].modelindex);
for( j = 0; j < m_pSubModel[i].numverts; j++ )
Mod_StudioBoundVertex( bone_mins, bone_maxs, &vert_count, pverts[j] );
for( j = 0; j < pbodypart[i].nummodels; j++ )
{
pverts = (vec3_t *)((byte *)pstudiohdr + m_pSubModel[j].vertindex);
for( k = 0; k < m_pSubModel[j].numverts; k++ )
Mod_StudioBoundVertex( bone_mins, bone_maxs, &vert_count, pverts[k] );
}
}
pbones = (mstudiobone_t *)((byte *)pstudiohdr + pstudiohdr->boneindex);