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fix(include): avoid UB in event encoders/decoders. #56

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Merged
poiana merged 1 commit into from
Mar 18, 2025
Merged

fix(include): avoid UB in event encoders/decoders. #56

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17 changes: 12 additions & 5 deletions include/falcosecurity/events/decoders.h
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Original file line number Diff line number Diff line change
Expand Up @@ -48,11 +48,13 @@ class pluginevent_e_decoder
}

uint8_t* parambuf = ((uint8_t*)r.get_buf() + 26);

parambuf += sizeof(uint32_t);
m_datalen = *(uint32_t*)parambuf;
memcpy(&m_datalen, parambuf, sizeof(uint32_t));

parambuf += sizeof(uint32_t);
m_plugin_id = *(uint32_t*)parambuf;
memcpy(&m_plugin_id, parambuf, sizeof(uint32_t));

parambuf += sizeof(uint32_t);
m_data = (void*)parambuf;
}
Expand Down Expand Up @@ -96,15 +98,20 @@ class asyncevent_e_decoder
}

uint8_t* parambuf = ((uint8_t*)r.get_buf() + 26);

parambuf += sizeof(uint32_t);
uint32_t namelen = *(uint32_t*)parambuf;
uint32_t namelen;
memcpy(&namelen, parambuf, sizeof(uint32_t));

parambuf += sizeof(uint32_t);
m_datalen = *(uint32_t*)parambuf;
memcpy(&m_datalen, parambuf, sizeof(uint32_t));

parambuf += sizeof(uint32_t);
m_plugin_id = *(uint32_t*)parambuf;
memcpy(&m_plugin_id, parambuf, sizeof(uint32_t));

parambuf += sizeof(uint32_t);
m_name = (const char*)parambuf;

parambuf += namelen;
m_data = (void*)parambuf;
}
Expand Down
61 changes: 44 additions & 17 deletions include/falcosecurity/events/encoders.h
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Original file line number Diff line number Diff line change
Expand Up @@ -49,19 +49,31 @@ class pluginevent_e_encoder
w.grow(26 + (sizeof(uint32_t) * 2) + sizeof(uint32_t) + m_datalen);
uint8_t* evt = (uint8_t*)w.get_buf();
uint8_t* parambuf = evt + 26;
*((uint64_t*)(evt + 0)) = m_ts;
*((uint64_t*)(evt + 8)) = m_tid;
*((uint16_t*)(evt + 20)) = 322;
*((uint32_t*)(evt + 22)) = 2;
*((uint32_t*)parambuf) = sizeof(uint32_t);

memcpy(&evt[0], &m_ts, sizeof(m_ts));
memcpy(&evt[8], &m_tid, sizeof(m_tid));

uint16_t val_16 = 322;
memcpy(&evt[20], &val_16, sizeof(val_16));

uint32_t val_32 = 2;
memcpy(&evt[22], &val_32, sizeof(val_32));

val_32 = sizeof(uint32_t);
memcpy(parambuf, &val_32, sizeof(uint32_t));
parambuf += sizeof(uint32_t);
*((uint32_t*)parambuf) = m_datalen;

memcpy(parambuf, &m_datalen, sizeof(m_datalen));
parambuf += sizeof(uint32_t);
*((uint32_t*)parambuf) = m_plugin_id;

memcpy(parambuf, &m_plugin_id, sizeof(m_plugin_id));
parambuf += sizeof(uint32_t);

memcpy(parambuf, m_data, m_datalen);
parambuf += m_datalen;
*((uint32_t*)(evt + 16)) = (uint32_t)(parambuf - evt);

val_32 = (uint32_t)(parambuf - evt);
memcpy(&evt[16], &val_32, sizeof(val_32));
}

FALCOSECURITY_INLINE
Expand Down Expand Up @@ -109,23 +121,38 @@ class asyncevent_e_encoder
(m_name.length() + 1) + m_datalen);
uint8_t* evt = (uint8_t*)w.get_buf();
uint8_t* parambuf = evt + 26;
*((uint64_t*)(evt + 0)) = m_ts;
*((uint64_t*)(evt + 8)) = m_tid;
*((uint16_t*)(evt + 20)) = 402;
*((uint32_t*)(evt + 22)) = 3;
*((uint32_t*)parambuf) = sizeof(uint32_t);

memcpy(&evt[0], &m_ts, sizeof(m_ts));
memcpy(&evt[8], &m_tid, sizeof(m_tid));

uint16_t val_16 = 402;
memcpy(&evt[20], &val_16, sizeof(val_16));

uint32_t val_32 = 3;
memcpy(&evt[22], &val_32, sizeof(val_32));

val_32 = sizeof(uint32_t);
memcpy(parambuf, &val_32, sizeof(uint32_t));
parambuf += sizeof(uint32_t);
*((uint32_t*)parambuf) = m_name.length() + 1;

val_32 = m_name.length() + 1;
memcpy(parambuf, &val_32, sizeof(uint32_t));
parambuf += sizeof(uint32_t);
*((uint32_t*)parambuf) = m_datalen;

memcpy(parambuf, &m_datalen, sizeof(m_datalen));
parambuf += sizeof(uint32_t);
*((uint32_t*)parambuf) = m_plugin_id;

memcpy(parambuf, &m_plugin_id, sizeof(m_plugin_id));
parambuf += sizeof(uint32_t);

memcpy(parambuf, m_name.c_str(), m_name.length() + 1);
parambuf += m_name.length() + 1;

memcpy(parambuf, m_data, m_datalen);
parambuf += m_datalen;
*((uint32_t*)(evt + 16)) = (uint32_t)(parambuf - evt);

val_32 = (uint32_t)(parambuf - evt);
memcpy(&evt[16], &val_32, sizeof(val_32));
}

FALCOSECURITY_INLINE
Expand Down