Hi, On Wed, Jul 13, 2022 at 8:45 PM Paolo Bonzini <pbonz...@redhat.com> wrote: > > From: Mauro Matteo Cascella <mcasc...@redhat.com> > > Set current_req to NULL, not current_req->req, to prevent reusing a free'd > buffer in case of repeated SCSI cancel requests. Also apply the fix to > CLEAR QUEUE and BUS DEVICE RESET messages as well, since they also cancel > the request. > > Thanks to Alexander Bulekov for providing a reproducer. > > Fixes: CVE-2022-0216 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/972 > Signed-off-by: Mauro Matteo Cascella <mcasc...@redhat.com> > Tested-by: Alexander Bulekov <alx...@bu.edu> > Message-Id: <20220711123316.421279-1-mcasc...@redhat.com> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > Adjust the patch from v1 to v2 since the changes crossed > with the pull request. > > hw/scsi/lsi53c895a.c | 3 +- > tests/qtest/fuzz-lsi53c895a-test.c | 71 ++++++++++++++++++++++++++++++ > 2 files changed, 73 insertions(+), 1 deletion(-) > > diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c > index 99ea42d49b..ad5f5e5f39 100644 > --- a/hw/scsi/lsi53c895a.c > +++ b/hw/scsi/lsi53c895a.c > @@ -1030,7 +1030,7 @@ static void lsi_do_msgout(LSIState *s) > trace_lsi_do_msgout_abort(current_tag); > if (current_req && current_req->req) { > scsi_req_cancel(current_req->req); > - current_req->req = NULL; > + current_req = NULL; > } > lsi_disconnect(s); > break; > @@ -1056,6 +1056,7 @@ static void lsi_do_msgout(LSIState *s) > /* clear the current I/O process */ > if (s->current) { > scsi_req_cancel(s->current->req); > + current_req = NULL; > } > > /* As the current implemented devices scsi_disk and scsi_generic > diff --git a/tests/qtest/fuzz-lsi53c895a-test.c > b/tests/qtest/fuzz-lsi53c895a-test.c > index 2e8e67859e..6872c70d3a 100644 > --- a/tests/qtest/fuzz-lsi53c895a-test.c > +++ b/tests/qtest/fuzz-lsi53c895a-test.c > @@ -8,6 +8,74 @@ > #include "qemu/osdep.h" > #include "libqtest.h" > > +/* > + * This used to trigger a UAF in lsi_do_msgout() > + * https://gitlab.com/qemu-project/qemu/-/issues/972 > + */ > +static void test_lsi_do_msgout_cancel_req(void) > +{ > + QTestState *s; > + > + s = qtest_init("-M q35 -m 4G -display none -nodefaults "
This test does not run on machines with small size memory. Is 4G a must have for this test? > + "-device lsi53c895a,id=scsi " > + "-device scsi-hd,drive=disk0 " > + "-drive file=null-co://,id=disk0,if=none,format=raw"); > + > + qtest_outl(s, 0xcf8, 0x80000810); > + qtest_outl(s, 0xcf8, 0xc000); > + qtest_outl(s, 0xcf8, 0x80000810); > + qtest_outw(s, 0xcfc, 0x7); > + qtest_outl(s, 0xcf8, 0x80000810); > + qtest_outl(s, 0xcfc, 0xc000); > + qtest_outl(s, 0xcf8, 0x80000804); > + qtest_outw(s, 0xcfc, 0x05); > + qtest_writeb(s, 0x69736c10, 0x08); > + qtest_writeb(s, 0x69736c13, 0x58); > + qtest_writeb(s, 0x69736c1a, 0x01); > + qtest_writeb(s, 0x69736c1b, 0x06); > + qtest_writeb(s, 0x69736c22, 0x01); > + qtest_writeb(s, 0x69736c23, 0x07); > + qtest_writeb(s, 0x69736c2b, 0x02); > + qtest_writeb(s, 0x69736c48, 0x08); > + qtest_writeb(s, 0x69736c4b, 0x58); > + qtest_writeb(s, 0x69736c52, 0x04); > + qtest_writeb(s, 0x69736c53, 0x06); > + qtest_writeb(s, 0x69736c5b, 0x02); > + qtest_outl(s, 0xc02d, 0x697300); > + qtest_writeb(s, 0x5a554662, 0x01); > + qtest_writeb(s, 0x5a554663, 0x07); > + qtest_writeb(s, 0x5a55466a, 0x10); > + qtest_writeb(s, 0x5a55466b, 0x22); > + qtest_writeb(s, 0x5a55466c, 0x5a); > + qtest_writeb(s, 0x5a55466d, 0x5a); > + qtest_writeb(s, 0x5a55466e, 0x34); > + qtest_writeb(s, 0x5a55466f, 0x5a); > + qtest_writeb(s, 0x5a345a5a, 0x77); > + qtest_writeb(s, 0x5a345a5b, 0x55); > + qtest_writeb(s, 0x5a345a5c, 0x51); > + qtest_writeb(s, 0x5a345a5d, 0x27); > + qtest_writeb(s, 0x27515577, 0x41); > + qtest_outl(s, 0xc02d, 0x5a5500); > + qtest_writeb(s, 0x364001d0, 0x08); > + qtest_writeb(s, 0x364001d3, 0x58); > + qtest_writeb(s, 0x364001da, 0x01); > + qtest_writeb(s, 0x364001db, 0x26); > + qtest_writeb(s, 0x364001dc, 0x0d); > + qtest_writeb(s, 0x364001dd, 0xae); > + qtest_writeb(s, 0x364001de, 0x41); > + qtest_writeb(s, 0x364001df, 0x5a); > + qtest_writeb(s, 0x5a41ae0d, 0xf8); > + qtest_writeb(s, 0x5a41ae0e, 0x36); > + qtest_writeb(s, 0x5a41ae0f, 0xd7); > + qtest_writeb(s, 0x5a41ae10, 0x36); > + qtest_writeb(s, 0x36d736f8, 0x0c); > + qtest_writeb(s, 0x36d736f9, 0x80); > + qtest_writeb(s, 0x36d736fa, 0x0d); > + qtest_outl(s, 0xc02d, 0x364000); > + > + qtest_quit(s); > +} > + > /* > * This used to trigger the assert in lsi_do_dma() > * https://bugs.launchpad.net/qemu/+bug/697510 > @@ -44,5 +112,8 @@ int main(int argc, char **argv) > qtest_add_func("fuzz/lsi53c895a/lsi_do_dma_empty_queue", > test_lsi_do_dma_empty_queue); > > + qtest_add_func("fuzz/lsi53c895a/lsi_do_msgout_cancel_req", > + test_lsi_do_msgout_cancel_req); > + > return g_test_run(); > } Regards, Bin
