In the "TCPdump" exercise, after enabling the ASAN option to build libpcap, the building of "tcpdump" will fail

[unrav31]

Thank you very much for the tutorial, I learned a lot in it. I encountered some problems that confused me in the third exercise "TCPdump". I followed the prompts to enable AFL_USE_ASAN when building libpcap:

cd $HOME/fuzzing_tcpdump/libpcap-libpcap-1.8.1/
export LLVM_CONFIG="llvm-config-11"
CC=afl-clang-lto ./configure --enable-shared=no --prefix="$HOME/fuzzing_tcpdump/install/"
AFL_USE_ASAN=1 make
AFL_USE_ASAN=1 make install

Then build tcpdump:

cd $HOME/fuzzing_tcpdump/tcpdump-tcpdump-4.9.2/
CC=afl-clang-lto CPPFLAGS=-I$HOME/fuzzing_tcpdump/install/include/ LDFLAGS=-L$HOME/fuzzing_tcpdump/install/lib/ ./configure --prefix="$HOME/fuzzing_tcpdump/install/"
AFL_USE_ASAN=1 make
AFL_USE_ASAN=1 make install

An error will be returned when executing AFL_USE_ASAN=1 make:

configure: error: This is a bug, please follow the guidelines in CONTRIBUTING and include the
config.log file in your report.  If you have downloaded libpcap from
tcpdump.org, and built it yourself, please also include the config.log
file from the libpcap source directory, the Makefile from the libpcap
source directory, and the output of the make process for libpcap, as
this could be a problem with the libpcap that was built, and we will
not be able to determine why this is happening, and thus will not be
able to fix it, without that information, as we have not been able to
reproduce this problem ourselves.

The following is the complete error:

checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
checking for gcc... afl-clang-lto
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether afl-clang-lto accepts -g... yes
checking for afl-clang-lto option to accept ISO C89... none needed
checking whether the compiler supports the -ffloat-store option... no
checking for inline... inline
checking for __attribute__... yes
checking whether __attribute__((unused)) can be used without warnings... yes
checking whether __attribute__((noreturn)) can be applied to function pointers without warnings... yes
checking whether __attribute__((format)) can be used without warnings... yes
checking whether __attribute__((format)) can be applied to function pointers... yes
checking how to run the C preprocessor... afl-clang-lto -E
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking fcntl.h usability... yes
checking fcntl.h presence... yes
checking for fcntl.h... yes
checking rpc/rpc.h usability... yes
checking rpc/rpc.h presence... yes
checking for rpc/rpc.h... yes
checking rpc/rpcent.h usability... no
checking rpc/rpcent.h presence... no
checking for rpc/rpcent.h... no
checking netdnet/dnetdb.h usability... no
checking netdnet/dnetdb.h presence... no
checking for netdnet/dnetdb.h... no
checking for net/pfvar.h... no
checking for netinet/if_ether.h... yes
checking whether time.h and sys/time.h may both be included... yes
checking smi.h usability... no
checking smi.h presence... no
checking for smi.h... no
checking whether to enable the possibly-buggy SMB printer... yes
configure: WARNING: The SMB printer may have exploitable buffer overflows!!!
checking whether to drop root privileges by default... no
checking whether to chroot... no
checking for cap_enter... no
checking for cap_rights_limit... no
checking for cap_ioctls_limit... no
checking for openat... yes
checking whether to sandbox using capsicum... no
checking for library containing gethostbyname... none required
checking for library containing socket... none required
checking for library containing putmsg... no
checking whether the operating system supports IPv6... yes
checking ipv6 stack type... linux-glibc
checking for dnet_htoa declaration in netdnet/dnetdb.h... no
checking for vfprintf... yes
checking for strlcat... no
checking for strlcpy... no
checking for strdup... yes
checking for strsep... yes
checking for getopt_long... yes
checking for fork... yes
checking for vfork... yes
checking for strftime... yes
checking for setlinebuf... yes
checking for alarm... yes
checking for vsnprintf... yes
checking for snprintf... yes
checking return type of signal handlers... void
checking for sigaction... yes
checking for library containing dnet_htoa... no
checking for main in -lrpc... no
checking for library containing getrpcbynumber... none required
checking for local pcap library... ../libpcap-1.8.1/libpcap.a
checking for pcap-config... ../libpcap-1.8.1/pcap-config
checking for pcap_loop... no
configure: error: This is a bug, please follow the guidelines in CONTRIBUTING and include the
config.log file in your report.  If you have downloaded libpcap from
tcpdump.org, and built it yourself, please also include the config.log
file from the libpcap source directory, the Makefile from the libpcap
source directory, and the output of the make process for libpcap, as
this could be a problem with the libpcap that was built, and we will
not be able to determine why this is happening, and thus will not be
able to fix it, without that information, as we have not been able to
reproduce this problem ourselves.

But when I canceled AFL_USE_ASAN=1 when building libpcap and made directly, when I built tcpdump again, no error occurred, and AFL++ can also run normally. I don't quite understand whether the result I get by canceling AFL_USE_ASAN=1 is the same as expected. Is the cause of the build failure because the link library is damaged? Or is there something wrong with my operation during construction?

[3072L]

use AFL_USE_ASAN=1 when run configure

[antonio-morales]

Thank you for your collaboration @tclan126

As thanks, you have been added to the "Thanks" section

[3072L]

You're welcome antonio!!!