bspatch_fuzzer: guard againts integer overflow with bad patch
oldpos is a signed integer and an invalid input can cause integer
overflow. This CL makes sure the interger overflow doesn't happen.
The error message was:
../../../../../../../tmp/portage/dev-util/bsdiff-9999/work/bsdiff-9999/platform2/bsdiff/bspatch.cc:366:12: runtime error: signed integer overflow: 251 + 9223372036854775807 cannot be represented in type 'long'
Bug: crbug.com/950591
Test: cros_fuzz --board=amd64-generic reproduce --fuzzer bspatch_fuzzer --testcase ~/trunk/clusterfuzz-testcase-bspatch_fuzzer-5689939906920448 --package bsdiff --build-type ubsan
Change-Id: If1253483bc073cfb08867b531121d835078544bb
1 file changed
