| Message ID | 1479709262-4707-1-git-send-email-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 21.11.2016 um 07:21 schrieb Eric Auger: > Capability header next field is an offset relative to the start of > the INFO buffer. tmp->next is assigned the proper value but iterations > implemented in vfio_info_cap_add and vfio_info_cap_shift use next > as an offset between the headers. When coping with multiple capabilities > this leads to an Oops. > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > --- > drivers/vfio/vfio.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index d1d70e0..1e838d1 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -1763,7 +1763,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, > header->version = version; > > /* Add to the end of the capability chain */ > - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next) > + for (tmp = buf; tmp->next; tmp = buf + tmp->next) > ; /* nothing */ > Looks sane to me, tmp->next is always set to the old size, which corresponds to the offset from the start of the buffer. > tmp->next = caps->size; > @@ -1776,8 +1776,9 @@ EXPORT_SYMBOL_GPL(vfio_info_cap_add); > void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) > { > struct vfio_info_cap_header *tmp; > + void *buf = (void *)caps->buf; > > - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset) > + for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) > tmp->next += offset; Reviewed-by: David Hildenbrand <david@redhat.com>
On Mon, 21 Nov 2016 07:21:02 +0100 Eric Auger <eric.auger@redhat.com> wrote: > Capability header next field is an offset relative to the start of > the INFO buffer. tmp->next is assigned the proper value but iterations > implemented in vfio_info_cap_add and vfio_info_cap_shift use next > as an offset between the headers. When coping with multiple capabilities > this leads to an Oops. > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > --- > drivers/vfio/vfio.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index d1d70e0..1e838d1 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -1763,7 +1763,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, > header->version = version; > > /* Add to the end of the capability chain */ > - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next) > + for (tmp = buf; tmp->next; tmp = buf + tmp->next) > ; /* nothing */ > > tmp->next = caps->size; > @@ -1776,8 +1776,9 @@ EXPORT_SYMBOL_GPL(vfio_info_cap_add); > void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) > { > struct vfio_info_cap_header *tmp; > + void *buf = (void *)caps->buf; > > - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset) > + for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) > tmp->next += offset; > } > EXPORT_SYMBOL_GPL(vfio_info_cap_shift); Thanks, good to get this fixed before we start getting multiple entries in the chain and expose it via mdev. For that same reason I also don't see that this needs any sort of stable backport as the existing code works for the single entries in the tree. Applied to next branch for 4.10 with David's R-b. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index d1d70e0..1e838d1 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1763,7 +1763,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, header->version = version; /* Add to the end of the capability chain */ - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next) + for (tmp = buf; tmp->next; tmp = buf + tmp->next) ; /* nothing */ tmp->next = caps->size; @@ -1776,8 +1776,9 @@ EXPORT_SYMBOL_GPL(vfio_info_cap_add); void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) { struct vfio_info_cap_header *tmp; + void *buf = (void *)caps->buf; - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset) + for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) tmp->next += offset; } EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
Capability header next field is an offset relative to the start of the INFO buffer. tmp->next is assigned the proper value but iterations implemented in vfio_info_cap_add and vfio_info_cap_shift use next as an offset between the headers. When coping with multiple capabilities this leads to an Oops. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- drivers/vfio/vfio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)