diff options
Diffstat (limited to 'results/classifier/105/other/1888714')
| -rw-r--r-- | results/classifier/105/other/1888714 | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/results/classifier/105/other/1888714 b/results/classifier/105/other/1888714 new file mode 100644 index 00000000..30cab9e8 --- /dev/null +++ b/results/classifier/105/other/1888714 @@ -0,0 +1,79 @@ +other: 0.935 +mistranslation: 0.867 +instruction: 0.865 +graphic: 0.858 +device: 0.841 +semantic: 0.829 +assembly: 0.801 +vnc: 0.778 +network: 0.777 +KVM: 0.763 +boot: 0.759 +socket: 0.757 + +Memory Leak in hpet_timer results in unusable machine + +Fair warning: this might be specific to QTest (specifically its clock_step) command. This reproducer only works with -accel qtest. Build with --enable-sanitizers to exit once we hit 1G RSS. + +export ASAN_OPTIONS=hard_rss_limit_mb=1000 +cat << EOF | ./i386-softmmu/qemu-system-i386 -nographic \ +-nodefaults -qtest stdio -accel qtest +writeq 0xfed0000e 0x15151515151515f1 +clock_step +clock_step +clock_step +clock_step +writeq 0xfed00100 0x5e90c5be00ff5e9e +writeq 0xfed00109 0xffffe0ff5cfec0ff +clock_step +EOF + +On my machine it takes around 10 seconds to reach the RSS limit. + +Unfortunately, I can't find a way to tell ASAN to log each malloc to figure out whats going on, but running the original fuzzing test case with the libfuzzer -trace_malloc=2 flag, I found that the allocations happen here: + +MALLOC[130968] 0x60300069ac90 32 + #0 0x55fa3f615851 in __sanitizer_print_stack_trace (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x2683851) + #1 0x55fa3f55fe88 in fuzzer::PrintStackTrace() (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x25cde88) + #2 0x55fa3f5447d6 in fuzzer::MallocHook(void const volatile*, unsigned long) (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x25b27d6) + #3 0x55fa3f61bbb7 in __sanitizer::RunMallocHooks(void const*, unsigned long) (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x2689bb7) + #4 0x55fa3f596d75 in __asan::Allocator::Allocate(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*, __asan::AllocType, bool) (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x2604d75) + #5 0x55fa3f596f7a in __asan::asan_calloc(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*) (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x2604f7a) + #6 0x55fa3f60d173 in calloc (/home/alxndr/Development/qemu/build/i386-softmmu/qemu-fuzz-i386+0x267b173) + #7 0x7fb300737548 in g_malloc0 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x54548) + #8 0x55fa40157689 in async_run_on_cpu /home/alxndr/Development/qemu/cpus-common.c:163:10 + #9 0x55fa409fab83 in hpet_timer /home/alxndr/Development/qemu/hw/timer/hpet.c:376:9 + #10 0x55fa416a5751 in timerlist_run_timers /home/alxndr/Development/qemu/util/qemu-timer.c:572:9 + #11 0x55fa3fcfdac4 in qtest_clock_warp /home/alxndr/Development/qemu/softmmu/cpus.c:507:9 + #12 0x55fa3fd65c35 in qtest_process_command /home/alxndr/Development/qemu/softmmu/qtest.c:665:9 + #13 0x55fa3fd5e128 in qtest_process_inbuf /home/alxndr/Development/qemu/softmmu/qtest.c:710:9 + #14 0x55fa3fd5de67 in qtest_server_inproc_recv /home/alxndr/Development/qemu/softmmu/qtest.c:817:9 + #15 0x55fa4142b64b in qtest_sendf /home/alxndr/Development/qemu/tests/qtest/libqtest.c:424:5 + #16 0x55fa4142c482 in qtest_clock_step_next /home/alxndr/Development/qemu/tests/qtest/libqtest.c:864:5 + #17 0x55fa414b12d1 in general_fuzz /home/alxndr/Development/qemu/tests/qtest/fuzz/general_fuzz.c:581:17 + +It doesn't look like we ever exit out of the loop in timerlist_run_timers, ie timer_list->active_timers is always True. + + +Info From GDB: +#0 0x0000555558070d31 in address_space_stl_internal (as=0x55555f0e8f20 <address_space_memory>, addr=0x0, val=0x0, attrs=..., result=0x0, endian=DEVICE_LITTLE_ENDIAN) at /home/alxndr/Development/qemu/memory_ldst.inc.c:323 +#1 0x0000555558071339 in address_space_stl_le (as=0x55555f0e8f20 <address_space_memory>, addr=0x0, val=0x0, attrs=..., result=0x0) at /home/alxndr/Development/qemu/memory_ldst.inc.c:357 +#2 0x000055555a6a6f95 in update_irq (timer=0x61f0000005b8, set=0x1) at /home/alxndr/Development/qemu/hw/timer/hpet.c:210 +#3 0x000055555a6ae55f in hpet_timer (opaque=0x61f0000005b8) at /home/alxndr/Development/qemu/hw/timer/hpet.c:386 +#4 0x000055555c03d178 in timerlist_run_timers (timer_list=0x60b0000528f0) at /home/alxndr/Development/qemu/util/qemu-timer.c:572 +#5 0x000055555c03d6b5 in qemu_clock_run_timers (type=QEMU_CLOCK_VIRTUAL) at /home/alxndr/Development/qemu/util/qemu-timer.c:586 +#6 0x0000555558c3d0c4 in qtest_clock_warp (dest=0x3461864) at /home/alxndr/Development/qemu/softmmu/cpus.c:507 + + +-Alex + +Still reproduces with the current git version (commit 7fe7fae8b48e3f9c647) + +I moved this report over to QEMU's new bug tracker on gitlab.com. +Please continue with the discussion here: + +https://gitlab.com/qemu-project/qemu/-/issues/538 + +Thanks for moving it over! ... let's close this one here on Launchpad now. + + |