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Revert "lzma: Make sure we don't dereference past array"

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Commit 40e261b89b71 (lib/LzmaEnc: Validate "len" before subtracting)
ensures that the variable len is at least 2. As a result, GetLenToPosState(len)
never returns a value greater than or equal to kNumLenToPosStates,
making the changes introduced in the commit 16c0dbf4bc6a (lzma: Make
sure we don't dereference past array) unreachable and no longer necessary.

This reverts commit 16c0dbf4bc6a (lzma: Make sure we don't dereference past array).

Fixes: CID 481982

Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Lidong Chen 2025-06-23 17:42:32 +00:00 committed by Daniel Kiper
parent 2539ede82a
commit 2f2ed28d5a
1 changed files with 2 additions and 8 deletions
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10
grub-core/lib/LzmaEnc.c
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@ -1877,7 +1877,7 @@ static SRes LzmaEnc_CodeOneBlock(CLzmaEnc *p, Bool useLimits, UInt32 maxPackSize
} }
else else
{ {
UInt32 posSlot, lenToPosState; UInt32 posSlot;
RangeEnc_EncodeBit(&p->rc, &p->isRep[p->state], 0); RangeEnc_EncodeBit(&p->rc, &p->isRep[p->state], 0);
p->state = kMatchNextStates[p->state]; p->state = kMatchNextStates[p->state];
if (len < LZMA_MATCH_LEN_MIN) if (len < LZMA_MATCH_LEN_MIN)
@ -1888,13 +1888,7 @@ static SRes LzmaEnc_CodeOneBlock(CLzmaEnc *p, Bool useLimits, UInt32 maxPackSize
LenEnc_Encode2(&p->lenEnc, &p->rc, len - LZMA_MATCH_LEN_MIN, posState, !p->fastMode, p->ProbPrices); LenEnc_Encode2(&p->lenEnc, &p->rc, len - LZMA_MATCH_LEN_MIN, posState, !p->fastMode, p->ProbPrices);
pos -= LZMA_NUM_REPS; pos -= LZMA_NUM_REPS;
GetPosSlot(pos, posSlot); GetPosSlot(pos, posSlot);
lenToPosState = GetLenToPosState(len); RcTree_Encode(&p->rc, p->posSlotEncoder[GetLenToPosState(len)], kNumPosSlotBits, posSlot);
if (lenToPosState >= kNumLenToPosStates)
{
p->result = SZ_ERROR_DATA;
return CheckErrors(p);
}
RcTree_Encode(&p->rc, p->posSlotEncoder[lenToPosState], kNumPosSlotBits, posSlot);
if (posSlot >= kStartPosModelIndex) if (posSlot >= kStartPosModelIndex)
{ {