oss-fuzz: MemorySanitizer: use-of-uninitialized-value in inv_txfm_add_c
reproduce with ./tests/dav1d_fuzzer clusterfuzz-testcase-minimized-dav1d_fuzzer-5634939618328576
clusterfuzz-testcase-minimized-dav1d_fuzzer-5634939618328576
==841==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x7ff94b2f7cbc in inv_txfm_add_c (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x17ccbc)
#1 0x7ff94b2f5afd in inv_txfm_add_dct_dct_32x32_c (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x17aafd)
#2 0x7ff94b3441d9 in dav1d_recon_b_inter_16bpc (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x1c91d9)
#3 0x7ff94b210a67 in decode_b (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x95a67)
#4 0x7ff94b1ee1a2 in decode_sb (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x731a2)
#5 0x7ff94b1edc66 in decode_sb (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x72c66)
#6 0x7ff94b1ecd8c in dav1d_decode_tile_sbrow (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x71d8c)
#7 0x7ff94b1f72b0 in dav1d_decode_frame (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x7c2b0)
#8 0x7ff94b1fd007 in dav1d_submit_frame (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x82007)
#9 0x7ff94b1da422 in dav1d_parse_obus (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x5f422)
#10 0x7ff94b34eabe in dav1d_decode (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x1d3abe)
#11 0x4c67df in LLVMFuzzerTestOneInput (/home/janne/src/dav1d/build-msan-fuzz/tests/dav1d_fuzzer+0x4c67df)
#12 0x42e062 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /var/tmp/portage/sys-libs/compiler-rt-sanitizers-7.0.0/work/compiler-rt-7.0.0.src/lib/fuzzer/FuzzerLoop.cpp:576:15
#13 0x41fbad in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) /var/tmp/portage/sys-libs/compiler-rt-sanitizers-7.0.0/work/compiler-rt-7.0.0.src/lib/fuzzer/FuzzerDriver.cpp:280:6
#14 0x424782 in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) /var/tmp/portage/sys-libs/compiler-rt-sanitizers-7.0.0/work/compiler-rt-7.0.0.src/lib/fuzzer/FuzzerDriver.cpp:714:9
#15 0x44d642 in main /var/tmp/portage/sys-libs/compiler-rt-sanitizers-7.0.0/work/compiler-rt-7.0.0.src/lib/fuzzer/FuzzerMain.cpp:20:10
#16 0x7ff94a207ae6 in __libc_start_main (/lib64/libc.so.6+0x21ae6)
#17 0x41df69 in _start (/home/janne/src/dav1d/build-msan-fuzz/tests/dav1d_fuzzer+0x41df69)
SUMMARY: MemorySanitizer: use-of-uninitialized-value (/home/janne/src/dav1d/build-msan-fuzz/tests/../src/libdav1d.so.0+0x17ccbc) in inv_txfm_add_c