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Fix Heap-buffer-overflow READ in opj_jp2_apply_pclr #1441

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merged 2 commits into from Aug 12, 2022
Merged

Fix Heap-buffer-overflow READ in opj_jp2_apply_pclr #1441

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c8fef1d
Fix Heap-buffer-overflow READ in opj_jp2_apply_pclr
sashashura Aug 12, 2022
aab172e
Refix Fix Heap-buffer-overflow READ in opj_jp2_apply_pclr
sashashura Aug 12, 2022
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7 changes: 5 additions & 2 deletions src/lib/openjp2/jp2.c
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Expand Up @@ -1042,7 +1042,7 @@ static OPJ_BOOL opj_jp2_apply_pclr(opj_image_t *image,
OPJ_UINT32 *entries;
opj_jp2_cmap_comp_t *cmap;
OPJ_INT32 *src, *dst;
OPJ_UINT32 j, max;
OPJ_UINT32 j, max, newmax, oldmax;
OPJ_UINT16 i, nr_channels, cmp, pcol;
OPJ_INT32 k, top_k;

Expand Down Expand Up @@ -1108,7 +1108,10 @@ static OPJ_BOOL opj_jp2_apply_pclr(opj_image_t *image,
pcol = cmap[i].pcol;
src = old_comps[cmp].data;
assert(src); /* verified above */
max = new_comps[pcol].w * new_comps[pcol].h;
oldmax = old_comps[cmp].w * old_comps[cmp].h;
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shouldn't the fix to be just:
max = new_comps[i].w * new_comps[i].h;

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It can be... While I understand where and why it accesses out of bounds memory, my assumption about the fix can be wrong because I'm not so familiar with the code base. I have applied and tested your suggestion and the crash is gone.

newmax = new_comps[pcol].w * new_comps[pcol].h;

max = oldmax < newmax ? oldmax : newmax;

/* Direct use: */
if (cmap[i].mtyp == 0) {
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