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That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Li Qiang , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Qemu Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Gerd Hoffmann =E4=BA=8E2020=E5=B9=B49=E6=9C=881=E6=97= =A5=E5=91=A8=E4=BA=8C =E4=B8=8B=E5=8D=8810:12=E5=86=99=E9=81=93=EF=BC=9A > > 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 > Reported-by: Philippe Mathieu-Daud=C3=A9 > Signed-off-by: Gerd Hoffmann > Reviewed-by: Philippe Mathieu-Daud=C3=A9 Reviewed-by: Li Qiang > --- > hw/display/cirrus_vga.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c > index 212d6f5e6145..5d1f62e50e67 100644 > --- a/hw/display/cirrus_vga.c > +++ b/hw/display/cirrus_vga.c > @@ -640,10 +640,16 @@ static void cirrus_invalidate_region(CirrusVGAState= * s, int off_begin, > } > > for (y =3D 0; y < lines; y++) { > - off_cur =3D off_begin; > + off_cur =3D off_begin & s->cirrus_addr_mask; > off_cur_end =3D ((off_cur + bytesperline - 1) & s->cirrus_addr_m= ask) + 1; > - assert(off_cur_end >=3D off_cur); > - memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off= _cur); > + if (off_cur_end >=3D 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 + 1 - off_cur); > + memory_region_set_dirty(&s->vga.vram, 0, off_cur_end); > + } > off_begin +=3D off_pitch; > } > } > -- > 2.27.0 > >