Validate buffer length before reading fields in Packet::readFrom#1666
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weebl2000 wants to merge 2 commits intomeshcore-dev:devfrom
Open
Validate buffer length before reading fields in Packet::readFrom#1666weebl2000 wants to merge 2 commits intomeshcore-dev:devfrom
weebl2000 wants to merge 2 commits intomeshcore-dev:devfrom
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readFrom reads the header byte, transport codes (4 bytes), and path_len from the source buffer before any length validation. With a short input, these reads go past the end of the buffer. Add upfront length checks: minimum 2 bytes overall, transport codes require 4 additional bytes, and path must fit before the remaining payload.
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Severity: Low
Summary
Packet::readFromreads the header byte, transport codes (4 bytes if present), andpath_lenfrom the source buffer before performing any length validation. With a short input (e.g.len = 0), these reads go past the end of the source buffer.Unlike the main radio receive path (which parses packets inline in
Dispatcher::checkRecvwith proper bounds checking),readFromis used by bridge interfaces (RS232, ESP-NOW) andimportContact(flash blob storage). A corrupted blob or malformed bridge frame could trigger the over-read.Fix
Add upfront length checks:
Test plan
Heltec_v3_companion_radio_ble