| Message ID | 20230717162126.11693-1-eric.auger@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [for-8.1,v2] hw/virtio-iommu: Fix potential OOB access in virtio_iommu_handle_command() | expand |
On 17/7/23 18:21, Eric Auger wrote: > In the virtio_iommu_handle_command() when a PROBE request is handled, > output_size takes a value greater than the tail size and on a subsequent > iteration we can get a stack out-of-band access. Initialize the > output_size on each iteration. A backtrace would be helpful (or reproducer). > The issue was found with ASAN. Credits to: > Yiming Tao(Zhejiang University) > Gaoning Pan(Zhejiang University) > > Fixes: 1733eebb9e7 ("virtio-iommu: Implement RESV_MEM probe request") > Signed-off-by: Eric Auger <eric.auger@redhat.com> > Reported-by: Mauro Matteo Cascella <mcascell@redhat.com> Did you mean: Reported-by: Yiming Tao <taoym@zju.edu.cn> ? > Cc: qemu-stable@nongnu.org > > --- > - added the Cc: qemu-stable@nongnu.org and copied 2 persons involved > in the reporting loop > --- > hw/virtio/virtio-iommu.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Hi Philippe, On 7/17/23 19:26, Philippe Mathieu-Daudé wrote: > On 17/7/23 18:21, Eric Auger wrote: >> In the virtio_iommu_handle_command() when a PROBE request is handled, >> output_size takes a value greater than the tail size and on a subsequent >> iteration we can get a stack out-of-band access. Initialize the >> output_size on each iteration. > > A backtrace would be helpful (or reproducer). Well the way to hit it in explained above. PROBE request followed by a different request consumed within the same virtio_iommu_handle_command() call > >> The issue was found with ASAN. Credits to: >> Yiming Tao(Zhejiang University) >> Gaoning Pan(Zhejiang University) >> >> Fixes: 1733eebb9e7 ("virtio-iommu: Implement RESV_MEM probe request") >> Signed-off-by: Eric Auger <eric.auger@redhat.com> >> Reported-by: Mauro Matteo Cascella <mcascell@redhat.com> > > Did you mean: > > Reported-by: Yiming Tao <taoym@zju.edu.cn> > > ? If I understand correctly trhe actual people who found the issue using the tool were those I mentionned in the credits section in the commit msg. but unfortunately I don't have their full address. Mauro Matteo forwarded me the report which transited though Yiming Tao. Anyway I will be glad to put more precise in the R-b tags if I get some additional info. Thanks Eric > >> Cc: qemu-stable@nongnu.org >> >> --- >> - added the Cc: qemu-stable@nongnu.org and copied 2 persons involved >> in the reporting loop >> --- >> hw/virtio/virtio-iommu.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) > > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> >
diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index 201127c488..4dcf1d5c62 100644 --- a/hw/virtio/virtio-iommu.c +++ b/hw/virtio/virtio-iommu.c @@ -728,13 +728,15 @@ static void virtio_iommu_handle_command(VirtIODevice *vdev, VirtQueue *vq) VirtIOIOMMU *s = VIRTIO_IOMMU(vdev); struct virtio_iommu_req_head head; struct virtio_iommu_req_tail tail = {}; - size_t output_size = sizeof(tail), sz; VirtQueueElement *elem; unsigned int iov_cnt; struct iovec *iov; void *buf = NULL; + size_t sz; for (;;) { + size_t output_size = sizeof(tail); + elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); if (!elem) { return;
In the virtio_iommu_handle_command() when a PROBE request is handled, output_size takes a value greater than the tail size and on a subsequent iteration we can get a stack out-of-band access. Initialize the output_size on each iteration. The issue was found with ASAN. Credits to: Yiming Tao(Zhejiang University) Gaoning Pan(Zhejiang University) Fixes: 1733eebb9e7 ("virtio-iommu: Implement RESV_MEM probe request") Signed-off-by: Eric Auger <eric.auger@redhat.com> Reported-by: Mauro Matteo Cascella <mcascell@redhat.com> Cc: qemu-stable@nongnu.org --- - added the Cc: qemu-stable@nongnu.org and copied 2 persons involved in the reporting loop --- hw/virtio/virtio-iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)