Fix out-of-bounds heap write in SnoopLogger
If specific Developer Options are enabled (such as SnoopLogger filtering active with the PBAP/MAP filter profile set to "magic"), a malicious Bluetooth controller can send a short HCI ACL packet that triggers a heap out-of-bounds write in `SnoopLogger::PayloadStrip()`. This occurs because a fixed string ('PROHIBITED') is written to the payload, and if the packet is extremely small (e.g., 8 bytes), the heap-allocated buffer does not have sufficient capacity.
A safeguard in `FilterCapturedPacket` intended to expand the buffer for small packets was logically inverted, meaning short packets were incorrectly skipped from being resized.
This commit fixes the issue by changing the guard condition from `>` to `<=`. This ensures that small packets correctly receive an `EXTRA_BUF_SIZE` padding, providing enough underlying buffer space for the "PROHIBITED" string overwrite and preventing the out-of-bounds heap write.
Test: alint against snoop_logger.cc; m bluetooth_test net_test_bluetooth bluetooth_packet_parser_test
Bug: 522372274
Flag: EXEMPT BUGFIX
This was autogenerated by MendIt (go/androidmendit)
(cherry picked from commit 0083751f4ce0a648674ee6e31b480bafa2e0e97e)
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:0e7667da9b935ceb7dd627d2b9b67d7b9bd1bbf2
Merged-In: I3fae8e1b8af9f05970de542317bcdcc3d020bf9e
Change-Id: I3fae8e1b8af9f05970de542317bcdcc3d020bf9e
Just build AOSP - Fluoride is there by default.
Instructions for a Debian based distribution:
You‘ll want to download some pre-requisite packages as well. If you’re currently configured for AOSP development, you should have most required packages. Otherwise, you can use the following apt-get list or use the --run-bootstrap option on build.py (see below) to get a list of packages missing on your system:
sudo apt-get install repo git-core gnupg flex bison gperf build-essential \ zip curl zlib1g-dev gcc-multilib g++-multilib \ x11proto-core-dev libx11-dev libncurses5 \ libgl1-mesa-dev libxml2-utils xsltproc unzip liblz4-tool libssl-dev \ libc++-dev libevent-dev \ flatbuffers-compiler libflatbuffers1 openssl \ libflatbuffers-dev libfmt-dev libtinyxml2-dev \ libglib2.0-dev libevent-dev libnss3-dev libdbus-1-dev \ libprotobuf-dev ninja-build generate-ninja protobuf-compiler \ libre2-9 debmake \ llvm libc++abi-dev \ libre2-dev libdouble-conversion-dev \ libgtest-dev libgmock-dev libabsl-dev
You will also need a recent-ish version of Rust and Cargo. Please follow the instructions on Rustup to install a recent version.
mkdir ~/fluoride cd ~/fluoride git clone https://android.googlesource.com/platform/packages/modules/Bluetooth
build.py is the helper script used to build Fluoride for Linux (i.e. Floss). It accepts a --run-bootstrap option that will set up your build staging directory and also make sure you have all required system packages to build (should work on Debian and Ubuntu). You will still need to build some unpackaged dependencies (like libchrome, modp_b64, googletest, etc).
To use it:
./build.py --run-bootstrap
This will install your bootstrapped build environment to ~/.floss. If you want to change this, just pass in --bootstrap-dir to the script.
The following third-party dependencies are necessary but currently unavailable via a package manager. You may have to build these from source and install them to your local environment.
We provide a script to produce debian packages for those components. Please see the instructions in build/dpkg/README.txt for more details.
cd system/build/dpkg mkdir -p outdir/{modp_b64,libchrome} # Build and install modp_b64 pushd modp_b64 ./gen-src-pkg.sh $(readlink -f ../outdir/modp_b64) popd sudo dpkg -i outdir/modp_b64/*.deb # Build and install libchrome pushd libchrome ./gen-src-pkg.sh $(readlink -f ../outdir/libchrome) popd sudo dpkg -i outdir/libchrome/*.deb
Note: Handled by --run-bootstrap option.
Run the following to install Rust dependencies:
cargo install cxxbridge-cmd
Note: Handled by --run-bootstrap option.
For host build, we depend on a few other repositories:
Clone these all somewhere and create your staging environment.
export STAGING_DIR=path/to/your/staging/dir mkdir ${STAGING_DIR} mkdir -p ${STAGING_DIR}/external ln -s $(readlink -f ${PLATFORM2_DIR}/common-mk) ${STAGING_DIR}/common-mk ln -s $(readlink -f ${PLATFORM2_DIR}/.gn) ${STAGING_DIR}/.gn ln -s $(readlink -f ${RUST_CRATE_DIR}) ${STAGING_DIR}/external/rust ln -s $(readlink -f ${PROTO_LOG_DIR}) ${STAGING_DIR}/external/proto_logging
We provide a build script to automate building assuming you've staged your build environment already as above. At this point, make sure you have all the pre-requisites installed (i.e. bootstrap option and other dependencies above) or you will see failures. In addition, you may need to set a --libdir= if your libraries are not stored in /usr/lib by default.
./build.py
This will build all targets to the output directory at --bootstrap-dir (which defaults to ~/.floss). You can also build each stage separately (if you want to iterate on something specific):
You can choose to run only a specific stage by passing an arg via --target.
Currently, Rust builds are a separate stage that uses Cargo to build. See gd/rust/README.md for more information. If you are iterating on Rust code and want to add new crates, you may also want to use the --no-vendored-rust option (which will let you use crates.io instead of using a pre-populated vendored crates repo).
By default on Linux, we statically link libbluetooth so you can just run the binary directly. By default, it will try to run on hci0 but you can pass it --hci=N, where N corresponds to /sys/class/bluetooth/hciN.
$OUTPUT_DIR/debug/btadapterd --hci=$HCI INIT_gd_hci=true