From: David Hildenbrand Date: Mon, 12 Jul 2021 08:31:35 +0000 (+0200) Subject: vfio: Fix CID 1458134 in vfio_register_ram_discard_listener() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a5dba9bc0552785b91315d457b9397ebd833224b;p=qemu.git vfio: Fix CID 1458134 in vfio_register_ram_discard_listener() CID 1458134: Integer handling issues (BAD_SHIFT) In expression "1 << ctz64(container->pgsizes)", left shifting by more than 31 bits has undefined behavior. The shift amount, "ctz64(container->pgsizes)", is 64. Commit 5e3b981c330c ("vfio: Support for RamDiscardManager in the !vIOMMU case") added an assertion that our granularity is at least as big as the page size. Although unlikely, we could have a page size that does not fit into 32 bit. In that case, we'd try shifting by more than 31 bit. Let's use 1ULL instead and make sure we're not shifting by more than 63 bit by asserting that any bit in container->pgsizes is set. Fixes: CID 1458134 Cc: Alex Williamson Cc: Eduardo Habkost Cc: "Michael S. Tsirkin" Cc: Paolo Bonzini Cc: Dr. David Alan Gilbert Cc: Igor Mammedov Cc: Pankaj Gupta Cc: Peter Xu Cc: Auger Eric Cc: Wei Yang Cc: teawater Cc: Marek Kedzierski Signed-off-by: David Hildenbrand Reviewed-by: Igor Mammedov Reviewed-by: Pankaj Gupta Link: https://lore.kernel.org/r/20210712083135.15755-1-david@redhat.com Signed-off-by: Alex Williamson --- diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 3f0d111360..8728d4d5c2 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -783,7 +783,8 @@ static void vfio_register_ram_discard_listener(VFIOContainer *container, section->mr); g_assert(vrdl->granularity && is_power_of_2(vrdl->granularity)); - g_assert(vrdl->granularity >= 1 << ctz64(container->pgsizes)); + g_assert(container->pgsizes && + vrdl->granularity >= 1ULL << ctz64(container->pgsizes)); ram_discard_listener_init(&vrdl->listener, vfio_ram_discard_notify_populate,