Fix for buffer overflow in BLE L2CAP #1662
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
This PR fixes a buffer overflow in the BLE L2CAP credit-based flow control.
The overflow occurs in the
input_l2cap_frame_flow_channelfunction, as an adversary is able to control the amount of data copied by memcpy (source).To fix this issue I suggest to:
payload_lenis larger thanBLE_L2CAP_NODE_MTU, which is the length of the destination array.payload_lenof the current fragment and thecurrent_indexof therx_bufferis larger thanBLE_L2CAP_NODE_MTU, which is the length of the destination array.In both cases illegal frames are simply dropped.