Code simply asserts that there is no wraparound instead of handling it properly. The assert() can be triggered by the guest (must be privilidged inside the guest though). Fix it.
Buglink: https://bugs.launchpad.net/qemu/+bug/1880189 Cc: Li Qiang <liq...@163.com> Reported-by: Alexander Bulekov <alx...@bu.edu> Signed-off-by: Gerd Hoffmann <kra...@redhat.com> --- hw/display/cirrus_vga.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 212d6f5e6145..b91b64347473 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -640,10 +640,15 @@ static void cirrus_invalidate_region(CirrusVGAState * s, int off_begin, } for (y = 0; y < lines; y++) { - off_cur = off_begin; + off_cur = off_begin & s->cirrus_addr_mask; off_cur_end = ((off_cur + bytesperline - 1) & s->cirrus_addr_mask) + 1; - assert(off_cur_end >= off_cur); - memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off_cur); + if (off_cur_end >= off_cur) { + memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off_cur); + } else { + /* wraparound */ + memory_region_set_dirty(&s->vga.vram, off_cur, s->cirrus_addr_mask - off_cur); + memory_region_set_dirty(&s->vga.vram, 0, off_cur_end); + } off_begin += off_pitch; } } -- 2.27.0
