On 19/09/2016 18:59, Laszlo Ersek wrote: > On 09/19/16 17:55, Stefan Hajnoczi wrote: >> On Mon, Sep 19, 2016 at 02:36:11PM +0530, P J P wrote: >>> From: Prasad J Pandit <p...@fedoraproject.org> >>> >>> virtio back end uses set of buffers to facilitate I/O operations. >>> If its size is too large, 'cpu_physical_memory_map' could return >>> a null address. This would result in a null dereference while >>> un-mapping descriptors. Add check to avoid it. >>> >>> Reported-by: Qinghao Tang <luodalon...@gmail.com> >>> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> >>> --- >>> hw/virtio/virtio.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> Update per: >>> -> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg03889.html >>> >>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c >>> index 15ee3a7..311dd0b 100644 >>> --- a/hw/virtio/virtio.c >>> +++ b/hw/virtio/virtio.c >>> @@ -472,6 +472,11 @@ static void virtqueue_map_desc(unsigned int *p_num_sg, >>> hwaddr *addr, struct iove >>> } >>> >>> iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write); >>> + if (!iov[num_sg].iov_base) { >>> + error_report("virtio: bogus descriptor or out of resources"); >>> + exit(EXIT_FAILURE); >> >> exit(1) is used everywhere else in the file (including just a few lines >> above in the same function). Please use exit(1) for consistency. > > Laurent's pending series > > [Qemu-devel] [PATCH 00/26] trivial: use exit(EXIT_SUCCESS) and > exit(EXIT_FAILURE) > > specifically his patch > > [Qemu-devel] [PATCH 11/26] pci, virtio: use exit(EXIT_SUCCESS) and > exit(EXIT_FAILURE) > > converts the argument of the exit() that you name to EXIT_FAILURE. > > So using EXIT_FAILURE in Prasad's patch is actually what will uphold > consistency. > >> Looks fine otherwise. >>
Laszlo, it seems Peter (and some others) would prefer to use exit(1) instead of exit(EXIT_FAILURE), so I don't think my series will be applied. Laurent