fuzz/oss-fuzz/build_samba: fetch fuzz seeds

There is a git repository at
https://gitlab.com/samba-team/samba-fuzz-seeds that contains the
seeds. When the master branch of that repository is updated, a CI job
runs that creates a zip file of all the seeds as an artifact. That zip
file is downloaded and unpacked by oss_fuzz/build_samba. The contents
of that zip are further zips that contain the seeds for each fuzzing
binary; these are placed next to the binaries in the manner that
oss-fuzz expects.

That is, beside 'fuzz_foo', we put 'fuzz_foo_seed_corpus.zip' which
contains a pile of fuzz_foo seeds.

There may be times when a new fuzz target does not have a seed corpus,
and times when a removed fuzz target leaves behind a seed corpus.
This is OK, so we don't insist on an exact match between the target
names and the zip names, only that there is some overlap.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Wed Oct 21 03:47:35 UTC 2020 on sn-devel-184

2 files changed, 27 insertions, 0 deletions

diff --git a/lib/fuzzing/oss-fuzz/build_samba.sh b/lib/fuzzing/oss-fuzz/build_samba.sh
index ff382e22a25..b27c7b7d5c8 100755
--- a/lib/fuzzing/oss-fuzz/build_samba.sh
+++ b/lib/fuzzing/oss-fuzz/build_samba.sh
@@ -110,4 +110,15 @@ do
 
     # Truncate the original binary to save space
     echo -n > $x
+
 done
+
+# Grap the seeds dictionary from github and put the seed zips in place
+# beside their executables.
+
+wget https://gitlab.com/samba-team/samba-fuzz-seeds/-/jobs/artifacts/master/download?job=zips \
+     -O seeds.zip
+
+# We might not have unzip, but we do have python
+$PYTHON -mzipfile -e seeds.zip  $OUT
+rm -f seeds.zip
diff --git a/lib/fuzzing/oss-fuzz/check_build.sh b/lib/fuzzing/oss-fuzz/check_build.sh
index cc69cf26418..b971d2c1bb0 100755
--- a/lib/fuzzing/oss-fuzz/check_build.sh
+++ b/lib/fuzzing/oss-fuzz/check_build.sh
@@ -13,8 +13,15 @@ OUT=$1
 
 # build_samba.sh will have put a non-zero number of fuzzers here.  If
 # there are none, this will fail as it becomes literally fuzz_*
+
+seeds_found=no
+
 for bin in $OUT/fuzz_*
 do
+    # we only want to look at the elf files, not the zips
+    if [ ${bin%_seed_corpus.zip} != $bin ]; then
+        continue
+    fi
     # Confirm that the chrpath was reset to lib/ in the same directory
     # as the binary
     chrpath -l $bin | grep 'RUNPATH=$ORIGIN/lib'
@@ -22,4 +29,13 @@ do
     # Confirm that we link to at least some libraries in this
     # directory (shows that the libraries were found and copied).
     ldd $bin | grep "$OUT/lib"
+
+    if [ -f ${bin}_seed_corpus.zip ]; then
+        seeds_found=yes
+    fi
 done
+
+if [ $seeds_found = no ]; then
+    echo "no seed zip files were found!"
+    exit 1
+fi