Add boundary checks to prevent memory safety issues in BgpLayer::getHeaderLen #1954
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Dimi1010
reviewed
Sep 10, 2025
I think the error is that Windows can't contain |
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## dev #1954 +/- ##
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- Coverage 83.51% 83.49% -0.02%
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Files 310 310
Lines 54884 54910 +26
Branches 12220 12223 +3
==========================================
+ Hits 45834 45849 +15
- Misses 7786 8197 +411
+ Partials 1264 864 -400
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Dimi1010
approved these changes
Sep 15, 2025
seladb
reviewed
Sep 18, 2025
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| if (m_Data - m_Packet->m_RawPacket->getRawData() + static_cast<ptrdiff_t>(offsetInLayer) > | ||
| static_cast<ptrdiff_t>(m_Packet->m_RawPacket->getRawDataLen())) | ||
| { | ||
| PCPP_LOG_ERROR("Requested offset is larger than total packet length"); | ||
| return false; | ||
| } | ||
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| if (m_NextLayer != nullptr && static_cast<ptrdiff_t>(offsetInLayer) > m_NextLayer->m_Data - m_Data) | ||
| { | ||
| PCPP_LOG_ERROR("Requested offset exceeds current layer's boundary"); | ||
| return false; | ||
| } |
There was a problem hiding this comment.
Why are these checks needed? All we need to check is that offsetInLayer is within the layer's boundary, which means it is smaller than or equal to m_DataLen. Why do we need to compare it to the whole packet or involve m_NextLayer?
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| if (m_Data - m_Packet->m_RawPacket->getRawData() + static_cast<ptrdiff_t>(offsetInLayer) + | ||
| static_cast<ptrdiff_t>(numOfBytesToShorten) > | ||
| static_cast<ptrdiff_t>(m_Packet->m_RawPacket->getRawDataLen())) | ||
| { | ||
| PCPP_LOG_ERROR("Requested number of bytes to shorten is larger than total packet length"); | ||
| return false; | ||
| } | ||
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| if (m_NextLayer != nullptr && | ||
| static_cast<ptrdiff_t>(offsetInLayer) + static_cast<ptrdiff_t>(numOfBytesToShorten) > | ||
| m_NextLayer->m_Data - m_Data) | ||
| { | ||
| PCPP_LOG_ERROR("Requested number of bytes to shorten exceeds current layer's boundary"); | ||
| return false; | ||
| } |
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| if (dataPtr > m_RawPacket->getRawData() + m_RawPacket->getRawDataLen()) | ||
| break; |
There was a problem hiding this comment.
How can such a thing happen? curLayer->getHeaderLen() should never exceed the packet data, unless we have a bug in one of the layers
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| if (dataPtr > m_RawPacket->getRawData() + m_RawPacket->getRawDataLen()) | ||
| break; |
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Closes #1864
This PR fixes heap-use-after-free and heap-buffer-overflow issues in BgpLayer::getHeaderLen(), reported by AddressSanitizer when extending or shortening the BGP layer
Added boundary checks to ensure that requested offsets and lengths do not exceed:
Added regression_samples