| Message ID | 20240617095529.115046-1-lulu@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] virtio-pci: Fix the use of an uninitialized irqfd. | expand |
Hi Cindy, On 17/6/24 11:55, Cindy Lu wrote: > The crash was reported in MAC OS and NixOS, here is the link for this bug > https://gitlab.com/qemu-project/qemu/-/issues/2334 > https://gitlab.com/qemu-project/qemu/-/issues/2321 > > The root cause is the function virtio_pci_set_guest_notifiers() was not called > in the virtio_input device.So the vector_irqfd was not initialized > > So the fix is to add the check for vector_irqfd. > > This fix is verified in vyatta,MacOS,NixOS,fedora system. > > The bt tree for this bug is: > Thread 6 "CPU 0/KVM" received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0x7c817be006c0 (LWP 1269146)] > kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > 817 if (irqfd->users == 0) { > (gdb) thread apply all bt > ... > Thread 6 (Thread 0x7c817be006c0 (LWP 1269146) "CPU 0/KVM"): > 0 kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > 1 kvm_virtio_pci_vector_use_one () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:893 > 2 0x00005983657045e2 in memory_region_write_accessor () at ../qemu-9.0.0/system/memory.c:497 > 3 0x0000598365704ba6 in access_with_adjusted_size () at ../qemu-9.0.0/system/memory.c:573 > 4 0x0000598365705059 in memory_region_dispatch_write () at ../qemu-9.0.0/system/memory.c:1528 > 5 0x00005983659b8e1f in flatview_write_continue_step.isra.0 () at ../qemu-9.0.0/system/physmem.c:2713 > 6 0x000059836570ba7d in flatview_write_continue () at ../qemu-9.0.0/system/physmem.c:2743 > 7 flatview_write () at ../qemu-9.0.0/system/physmem.c:2774 > 8 0x000059836570bb76 in address_space_write () at ../qemu-9.0.0/system/physmem.c:2894 > 9 0x0000598365763afe in address_space_rw () at ../qemu-9.0.0/system/physmem.c:2904 > 10 kvm_cpu_exec () at ../qemu-9.0.0/accel/kvm/kvm-all.c:2917 > 11 0x000059836576656e in kvm_vcpu_thread_fn () at ../qemu-9.0.0/accel/kvm/kvm-accel-ops.c:50 > 12 0x0000598365926ca8 in qemu_thread_start () at ../qemu-9.0.0/util/qemu-thread-posix.c:541 > 13 0x00007c8185bcd1cf in ??? () at /usr/lib/libc.so.6 > 14 0x00007c8185c4e504 in clone () at /usr/lib/libc.so.6 > > Fixes: 2ce6cff94d ("virtio-pci: fix use of a released vector") > Cc: qemu-stable@nongnu.org > > Signed-off-by: Cindy Lu <lulu@redhat.com> > --- > hw/virtio/virtio-pci.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index b1d02f4b3d..502aad28b2 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1442,7 +1442,9 @@ static void virtio_pci_set_vector(VirtIODevice *vdev, > * Otherwise just need to set the new vector on the device. > */ > if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) { > - kvm_virtio_pci_vector_release_one(proxy, queue_no); > + if (proxy->vector_irqfd) { Shouldn't this go into called virtio_pci_get_notifier()? > + kvm_virtio_pci_vector_release_one(proxy, queue_no); We ignore this function return value, is it safe/expected? > + } > }
On Mon, Jun 17, 2024 at 6:38 PM Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > Hi Cindy, > > On 17/6/24 11:55, Cindy Lu wrote: > > The crash was reported in MAC OS and NixOS, here is the link for this bug > > https://gitlab.com/qemu-project/qemu/-/issues/2334 > > https://gitlab.com/qemu-project/qemu/-/issues/2321 > > > > The root cause is the function virtio_pci_set_guest_notifiers() was not called > > in the virtio_input device.So the vector_irqfd was not initialized > > > > So the fix is to add the check for vector_irqfd. > > > > This fix is verified in vyatta,MacOS,NixOS,fedora system. > > > > The bt tree for this bug is: > > Thread 6 "CPU 0/KVM" received signal SIGSEGV, Segmentation fault. > > [Switching to Thread 0x7c817be006c0 (LWP 1269146)] > > kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > > 817 if (irqfd->users == 0) { > > (gdb) thread apply all bt > > ... > > Thread 6 (Thread 0x7c817be006c0 (LWP 1269146) "CPU 0/KVM"): > > 0 kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > > 1 kvm_virtio_pci_vector_use_one () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:893 > > 2 0x00005983657045e2 in memory_region_write_accessor () at ../qemu-9.0.0/system/memory.c:497 > > 3 0x0000598365704ba6 in access_with_adjusted_size () at ../qemu-9.0.0/system/memory.c:573 > > 4 0x0000598365705059 in memory_region_dispatch_write () at ../qemu-9.0.0/system/memory.c:1528 > > 5 0x00005983659b8e1f in flatview_write_continue_step.isra.0 () at ../qemu-9.0.0/system/physmem.c:2713 > > 6 0x000059836570ba7d in flatview_write_continue () at ../qemu-9.0.0/system/physmem.c:2743 > > 7 flatview_write () at ../qemu-9.0.0/system/physmem.c:2774 > > 8 0x000059836570bb76 in address_space_write () at ../qemu-9.0.0/system/physmem.c:2894 > > 9 0x0000598365763afe in address_space_rw () at ../qemu-9.0.0/system/physmem.c:2904 > > 10 kvm_cpu_exec () at ../qemu-9.0.0/accel/kvm/kvm-all.c:2917 > > 11 0x000059836576656e in kvm_vcpu_thread_fn () at ../qemu-9.0.0/accel/kvm/kvm-accel-ops.c:50 > > 12 0x0000598365926ca8 in qemu_thread_start () at ../qemu-9.0.0/util/qemu-thread-posix.c:541 > > 13 0x00007c8185bcd1cf in ??? () at /usr/lib/libc.so.6 > > 14 0x00007c8185c4e504 in clone () at /usr/lib/libc.so.6 > > > > Fixes: 2ce6cff94d ("virtio-pci: fix use of a released vector") > > Cc: qemu-stable@nongnu.org > > > > Signed-off-by: Cindy Lu <lulu@redhat.com> > > --- > > hw/virtio/virtio-pci.c | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > index b1d02f4b3d..502aad28b2 100644 > > --- a/hw/virtio/virtio-pci.c > > +++ b/hw/virtio/virtio-pci.c > > @@ -1442,7 +1442,9 @@ static void virtio_pci_set_vector(VirtIODevice *vdev, > > * Otherwise just need to set the new vector on the device. > > */ > > if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) { > > - kvm_virtio_pci_vector_release_one(proxy, queue_no); > > + if (proxy->vector_irqfd) { > > Shouldn't this go into called virtio_pci_get_notifier()? > sure, will do > > + kvm_virtio_pci_vector_release_one(proxy, queue_no); > > We ignore this function return value, is it safe/expected? > sure, will add the check here thanks Cindy > > + } > > } > >
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index b1d02f4b3d..502aad28b2 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1442,7 +1442,9 @@ static void virtio_pci_set_vector(VirtIODevice *vdev, * Otherwise just need to set the new vector on the device. */ if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) { - kvm_virtio_pci_vector_release_one(proxy, queue_no); + if (proxy->vector_irqfd) { + kvm_virtio_pci_vector_release_one(proxy, queue_no); + } } /* Set the new vector on the device. */ if (queue_no == VIRTIO_CONFIG_IRQ_IDX) { @@ -1452,7 +1454,9 @@ static void virtio_pci_set_vector(VirtIODevice *vdev, } /* If the new vector changed need to set it up. */ if (kvm_irqfd && new_vector != VIRTIO_NO_VECTOR) { - kvm_virtio_pci_vector_use_one(proxy, queue_no); + if (proxy->vector_irqfd) { + kvm_virtio_pci_vector_use_one(proxy, queue_no); + } } }
The crash was reported in MAC OS and NixOS, here is the link for this bug https://gitlab.com/qemu-project/qemu/-/issues/2334 https://gitlab.com/qemu-project/qemu/-/issues/2321 The root cause is the function virtio_pci_set_guest_notifiers() was not called in the virtio_input device.So the vector_irqfd was not initialized So the fix is to add the check for vector_irqfd. This fix is verified in vyatta,MacOS,NixOS,fedora system. The bt tree for this bug is: Thread 6 "CPU 0/KVM" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7c817be006c0 (LWP 1269146)] kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 817 if (irqfd->users == 0) { (gdb) thread apply all bt ... Thread 6 (Thread 0x7c817be006c0 (LWP 1269146) "CPU 0/KVM"): 0 kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 1 kvm_virtio_pci_vector_use_one () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:893 2 0x00005983657045e2 in memory_region_write_accessor () at ../qemu-9.0.0/system/memory.c:497 3 0x0000598365704ba6 in access_with_adjusted_size () at ../qemu-9.0.0/system/memory.c:573 4 0x0000598365705059 in memory_region_dispatch_write () at ../qemu-9.0.0/system/memory.c:1528 5 0x00005983659b8e1f in flatview_write_continue_step.isra.0 () at ../qemu-9.0.0/system/physmem.c:2713 6 0x000059836570ba7d in flatview_write_continue () at ../qemu-9.0.0/system/physmem.c:2743 7 flatview_write () at ../qemu-9.0.0/system/physmem.c:2774 8 0x000059836570bb76 in address_space_write () at ../qemu-9.0.0/system/physmem.c:2894 9 0x0000598365763afe in address_space_rw () at ../qemu-9.0.0/system/physmem.c:2904 10 kvm_cpu_exec () at ../qemu-9.0.0/accel/kvm/kvm-all.c:2917 11 0x000059836576656e in kvm_vcpu_thread_fn () at ../qemu-9.0.0/accel/kvm/kvm-accel-ops.c:50 12 0x0000598365926ca8 in qemu_thread_start () at ../qemu-9.0.0/util/qemu-thread-posix.c:541 13 0x00007c8185bcd1cf in ??? () at /usr/lib/libc.so.6 14 0x00007c8185c4e504 in clone () at /usr/lib/libc.so.6 Fixes: 2ce6cff94d ("virtio-pci: fix use of a released vector") Cc: qemu-stable@nongnu.org Signed-off-by: Cindy Lu <lulu@redhat.com> --- hw/virtio/virtio-pci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)