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Fix server crash when read a malformed replication segment #9055

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Fix server crash when read a malformed replication segment #9055

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442d857
Fix server crash when read a malformed replication segment
XaBbl4 Jun 8, 2026
c5a30e3
Revert the length definition in the getString function back to how it…
XaBbl4 Jun 8, 2026
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19 changes: 15 additions & 4 deletions src/jrd/replication/Applier.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -127,13 +127,21 @@ namespace

const string& getAtomString()
{
const auto pos = getInt32();
const ULONG pos = static_cast<ULONG>(getInt32());

if (pos >= m_atoms.getCount())

@dyemanov dyemanov Jun 18, 2026

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I'd prefer explicit checks with a signed pos:

if (pos < 0 || pos >= m_atoms.getCount())

malformed();

return m_atoms[pos];
}

const MetaString getAtomMetaName()
{
const auto pos = getInt32();
const ULONG pos = static_cast<ULONG>(getInt32());

if (pos >= m_atoms.getCount())

@dyemanov dyemanov Jun 18, 2026

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Same as above.

malformed();

return m_atoms[pos];
}

Expand All @@ -154,7 +162,7 @@ namespace
{
const auto length = getInt32();

if (m_data + length > m_end)
if (length <= 0 || m_end - m_data < length)

@dyemanov dyemanov Jun 18, 2026

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I'd allow zero-length strings even if it looks impossible now.

malformed();

const string str((const char*) m_data, length);
Expand All @@ -164,7 +172,7 @@ namespace

const UCHAR* getBinary(ULONG length)
{
if (m_data + length > m_end)
if (m_end - m_data < length)
malformed();

const auto ptr = m_data;
Expand All @@ -185,6 +193,9 @@ namespace
void defineAtom()
{
const auto length = getByte();
if (length <= 0)

@dyemanov dyemanov Jun 18, 2026

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Same as above.

malformed();

const auto ptr = getBinary(length);
const MetaString name((const char*) ptr, length);
m_atoms.add(name);
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