Hello,
Reproducer:
cat << EOF | ./i386-softmmu/qemu-system-i386 -qtest stdio -monitor none -serial none -M pc-q35-5.0 -nographic
outl 0xcf8 0x8000fa24
outl 0xcfc 0xe1068000
outl 0xcf8 0x8000fa04
outw 0xcfc 0x7
outl 0xcf8 0x8000fb20
write 0xe1068304 0x1 0x21
write 0xe1068318 0x1 0x21
write 0xe1068384 0x1 0x21
write 0xe1068398 0x2 0x21
EOF
Stack trace:
#0 0x55bfabfe9ea0 in __libc_start_main /build/glibc-GwnBeO/glibc-2.30/csu/../csu/libc-start.c:308:16
#1 0x55bfabfc8ef9 in __sanitizer_print_stack_trace (build/i386-softmmu/qemu-fuzz-i386+0x7b7ef9)
#2 0x55bfabfaf933 in fuzzer::PrintStackTrace() FuzzerUtil.cpp:210:5
#3 0x7f88df76110f (/lib/x86_64-linux-gnu/libpthread.so.0+0x1410f)
#4 0x7f88df5a4760 in __libc_signal_restore_set /build/glibc-GwnBeO/glibc-2.30/signal/../sysdeps/unix/sysv/linux/internal-signals.h:84:10
#5 0x7f88df5a4760 in raise /build/glibc-GwnBeO/glibc-2.30/signal/../sysdeps/unix/sysv/linux/raise.c:48:3
#6 0x7f88df58e55a in abort /build/glibc-GwnBeO/glibc-2.30/stdlib/abort.c:79:7
#7 0x7f88df58e42e in __assert_fail_base /build/glibc-GwnBeO/glibc-2.30/assert/assert.c:92:3
#8 0x7f88df59d091 in __assert_fail /build/glibc-GwnBeO/glibc-2.30/assert/assert.c:101:3
#9 0x55bfabff7182 in address_space_unmap exec.c:3602:9
#10 0x55bfac4a452f in dma_memory_unmap include/sysemu/dma.h:148:5
#11 0x55bfac4a452f in map_page hw/ide/ahci.c:254:9
#12 0x55bfac4a1f98 in ahci_map_clb_address hw/ide/ahci.c:748:5
#13 0x55bfac4a1f98 in ahci_cond_start_engines hw/ide/ahci.c:276:14
#14 0x55bfac4a074e in ahci_port_write hw/ide/ahci.c:339:9
#15 0x55bfac4a074e in ahci_mem_write hw/ide/ahci.c:513:9
#16 0x55bfac0e0dc2 in memory_region_write_accessor memory.c:483:5
#17 0x55bfac0e0bde in access_with_adjusted_size memory.c:544:18
#18 0x55bfac0e0917 in memory_region_dispatch_write memory.c
#19 0x55bfabffa4fd in flatview_write_continue exec.c:3146:23
#20 0x55bfabff569b in flatview_write exec.c:3186:14
#21 0x55bfabff569b in address_space_write exec.c:3280:18
#22 0x55bfac8982a9 in op_write_pattern tests/qtest/fuzz/general_fuzz.c:407:5
#23 0x55bfac897749 in general_fuzz tests/qtest/fuzz/general_fuzz.c:481:17
#24 0x55bfac8930a2 in LLVMFuzzerTestOneInput tests/qtest/fuzz/fuzz.c:136:5
#25 0x55bfabfb0e68 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) FuzzerLoop.cpp:558:15
#26 0x55bfabfb0485 in fuzzer::Fuzzer::RunOne(unsigned char const*, unsigned long, bool, fuzzer::InputInfo*, bool*) FuzzerLoop.cpp:470:3
#27 0x55bfabfb18a1 in fuzzer::Fuzzer::MutateAndTestOne() FuzzerLoop.cpp:701:19
#28 0x55bfabfb2305 in fuzzer::Fuzzer::Loop(std::vector<fuzzer::SizedFile, fuzzer::fuzzer_allocator<fuzzer::SizedFile> >&) FuzzerLoop.cpp:837:5
#29 0x55bfabfa2018 in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) FuzzerDriver.cpp:846:6
#30 0x55bfabfb8722 in main FuzzerMain.cpp:19:10
#31 0x7f88df58fe0a in __libc_start_main /build/glibc-GwnBeO/glibc-2.30/csu/../csu/libc-start.c:308:16
#32 0x55bfabf97869 in _start (build/i386-softmmu/qemu-fuzz-i386+0x786869)
The same error can be triggered through ahci_map_fis_address @ hw/ide/ahci.c:721:5
Found with generic device fuzzer: https://<email address hidden>/
Please let me know if I can provide any further info.
Proposed fix:
https:/