On 11/23/21 14:42, Hanna Reitz wrote: > On 18.11.21 13:06, Philippe Mathieu-Daudé wrote: >> From: Alexander Bulekov <alx...@bu.edu> >> >> Without the previous commit, when running 'make check-qtest-i386' >> with QEMU configured with '--enable-sanitizers' we get: >> >> AddressSanitizer:DEADLYSIGNAL >> ================================================================= >> ==287878==ERROR: AddressSanitizer: SEGV on unknown address >> 0x000000000344 >> ==287878==The signal is caused by a WRITE memory access. >> ==287878==Hint: address points to the zero page. >> #0 0x564b2e5bac27 in blk_inc_in_flight >> block/block-backend.c:1346:5 >> #1 0x564b2e5bb228 in blk_pwritev_part block/block-backend.c:1317:5 >> #2 0x564b2e5bcd57 in blk_pwrite block/block-backend.c:1498:11 >> #3 0x564b2ca1cdd3 in fdctrl_write_data hw/block/fdc.c:2221:17 >> #4 0x564b2ca1b2f7 in fdctrl_write hw/block/fdc.c:829:9 >> #5 0x564b2dc49503 in portio_write softmmu/ioport.c:201:9 >> >> Add the reproducer for CVE-2021-20196. >> >> Signed-off-by: Alexander Bulekov <alx...@bu.edu> >> Message-Id: <20210319050906.14875-2-alx...@bu.edu> >> [PMD: Rebased, use global test_image] >> Reviewed-by: Darren Kenny <darren.ke...@oracle.com> >> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> >> --- >> tests/qtest/fdc-test.c | 21 +++++++++++++++++++++ >> 1 file changed, 21 insertions(+) > > Not sure if I’m doing something wrong, but: > > Using the global test_image brings a problem, namely that this test > fails unconditionally (for me at least...?), with the reason being that > the global QEMU instance (launched by qtest_start(), quit by > qtest_end()) still has that image open, so by launching a second > instance concurrently, I get this: > > qemu-system-x86_64: Failed to get "write" lock > Is another process using the image [/tmp/qtest.xV4IxX]?
Hmm I had too many odd problems running qtests in parallel so I switched to 'make check-qtest -j1' more than 1 year ago, which is probably why I haven't noticed that issue. Using another 'test_image' seems against code reuse principle, but at this point in release, duplicating it is simpler. Someone will clean that later =) > So either we need to use a different image file, or we need to quit the > global instance before using it (e.g. putting a qtest_end() at the > beginning of test_cve_*()), although the latter just seems wrong. > > Second, I can’t make this test fail. When I apply this patch first (to > master) and run it, I don’t get a SIGSEGV. Is your QEMU built with --enable-sanitizers ?
