50 lines
2.0 KiB
Diff
50 lines
2.0 KiB
Diff
|
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
||
|
|
Date: Thu, 9 Jul 2020 03:05:23 +0000
|
||
|
|
Subject: [PATCH] lzma: Make sure we don't dereference past array
|
||
|
|
|
||
|
|
The two dimensional array p->posSlotEncoder[4][64] is being dereferenced
|
||
|
|
using the GetLenToPosState() macro which checks if len is less than 5,
|
||
|
|
and if so subtracts 2 from it. If len = 0, that is 0 - 2 = 4294967294.
|
||
|
|
Obviously we don't want to dereference that far out so we check if the
|
||
|
|
position found is greater or equal kNumLenToPosStates (4) and bail out.
|
||
|
|
|
||
|
|
N.B.: Upstream LZMA 18.05 and later has this function completely rewritten
|
||
|
|
without any history.
|
||
|
|
|
||
|
|
Fixes: CID 51526
|
||
|
|
|
||
|
|
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
||
|
|
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
|
||
|
|
Upstream-commit-id: f91e043bda4
|
||
|
|
---
|
||
|
|
grub-core/lib/LzmaEnc.c | 10 ++++++++--
|
||
|
|
1 file changed, 8 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/grub-core/lib/LzmaEnc.c b/grub-core/lib/LzmaEnc.c
|
||
|
|
index f2ec04a8c..753e56a95 100644
|
||
|
|
--- a/grub-core/lib/LzmaEnc.c
|
||
|
|
+++ b/grub-core/lib/LzmaEnc.c
|
||
|
|
@@ -1877,13 +1877,19 @@ static SRes LzmaEnc_CodeOneBlock(CLzmaEnc *p, Bool useLimits, UInt32 maxPackSize
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
- UInt32 posSlot;
|
||
|
|
+ UInt32 posSlot, lenToPosState;
|
||
|
|
RangeEnc_EncodeBit(&p->rc, &p->isRep[p->state], 0);
|
||
|
|
p->state = kMatchNextStates[p->state];
|
||
|
|
LenEnc_Encode2(&p->lenEnc, &p->rc, len - LZMA_MATCH_LEN_MIN, posState, !p->fastMode, p->ProbPrices);
|
||
|
|
pos -= LZMA_NUM_REPS;
|
||
|
|
GetPosSlot(pos, posSlot);
|
||
|
|
- RcTree_Encode(&p->rc, p->posSlotEncoder[GetLenToPosState(len)], kNumPosSlotBits, posSlot);
|
||
|
|
+ lenToPosState = GetLenToPosState(len);
|
||
|
|
+ if (lenToPosState >= kNumLenToPosStates)
|
||
|
|
+ {
|
||
|
|
+ p->result = SZ_ERROR_DATA;
|
||
|
|
+ return CheckErrors(p);
|
||
|
|
+ }
|
||
|
|
+ RcTree_Encode(&p->rc, p->posSlotEncoder[lenToPosState], kNumPosSlotBits, posSlot);
|
||
|
|
|
||
|
|
if (posSlot >= kStartPosModelIndex)
|
||
|
|
{
|