• Arnd Bergmann's avatar
    virtio_balloon: prevent uninitialized variable use · 0c4c9449
    Arnd Bergmann authored
    commit f0bb2d50 upstream.
    
    The latest gcc-7.0.1 snapshot reports a new warning:
    
    virtio/virtio_balloon.c: In function 'update_balloon_stats':
    virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function [-Werror=uninitialized]
    virtio/virtio_balloon.c:260:26: error: 'events[3]' is used uninitialized in this function [-Werror=uninitialized]
    virtio/virtio_balloon.c:261:56: error: 'events[18]' is used uninitialized in this function [-Werror=uninitialized]
    virtio/virtio_balloon.c:262:56: error: 'events[17]' is used uninitialized in this function [-Werror=uninitialized]
    
    This seems absolutely right, so we should add an extra check to
    prevent copying uninitialized stack data into the statistics.
    >From all I can tell, this has been broken since the statistics code
    was originally added in 2.6.34.
    
    Fixes: 9564e138 ("virtio: Add memory statistics reporting to the balloon driver (V4)")
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    Signed-off-by: default avatarLadi Prosek <lprosek@redhat.com>
    Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    0c4c9449
virtio_balloon.c 17.5 KB