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[PATCH 37/47] virtio: use virtio accessor to access packed event
From: |
Michael Roth |
Subject: |
[PATCH 37/47] virtio: use virtio accessor to access packed event |
Date: |
Tue, 14 Dec 2021 18:01:15 -0600 |
From: Jason Wang <jasowang@redhat.com>
We used to access packed descriptor event and off_wrap via
address_space_{write|read}_cached(). When we hit the cache, memcpy()
is used which is not atomic which may lead a wrong value to be read or
wrote.
This patch fixes this by switching to use
virito_{stw|lduw}_phys_cached() to make sure the access is atomic.
Fixes: 683f7665679c1 ("virtio: event suppression support for packed ring")
Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211111063854.29060-2-jasowang@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit d152cdd6f6fad381e804c8185f0ba938030ccac9)
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
hw/virtio/virtio.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 2dbccb6b3f..c9567f09ed 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -249,13 +249,10 @@ static void vring_packed_event_read(VirtIODevice *vdev,
hwaddr off_off = offsetof(VRingPackedDescEvent, off_wrap);
hwaddr off_flags = offsetof(VRingPackedDescEvent, flags);
- address_space_read_cached(cache, off_flags, &e->flags,
- sizeof(e->flags));
+ e->flags = virtio_lduw_phys_cached(vdev, cache, off_flags);
/* Make sure flags is seen before off_wrap */
smp_rmb();
- address_space_read_cached(cache, off_off, &e->off_wrap,
- sizeof(e->off_wrap));
- virtio_tswap16s(vdev, &e->off_wrap);
+ e->off_wrap = virtio_lduw_phys_cached(vdev, cache, off_off);
virtio_tswap16s(vdev, &e->flags);
}
@@ -265,8 +262,7 @@ static void vring_packed_off_wrap_write(VirtIODevice *vdev,
{
hwaddr off = offsetof(VRingPackedDescEvent, off_wrap);
- virtio_tswap16s(vdev, &off_wrap);
- address_space_write_cached(cache, off, &off_wrap, sizeof(off_wrap));
+ virtio_stw_phys_cached(vdev, cache, off, off_wrap);
address_space_cache_invalidate(cache, off, sizeof(off_wrap));
}
@@ -275,8 +271,7 @@ static void vring_packed_flags_write(VirtIODevice *vdev,
{
hwaddr off = offsetof(VRingPackedDescEvent, flags);
- virtio_tswap16s(vdev, &flags);
- address_space_write_cached(cache, off, &flags, sizeof(flags));
+ virtio_stw_phys_cached(vdev, cache, off, flags);
address_space_cache_invalidate(cache, off, sizeof(flags));
}
--
2.25.1
- [PATCH 28/47] Partially revert "build: -no-pie is no functional linker flag", (continued)
- [PATCH 28/47] Partially revert "build: -no-pie is no functional linker flag", Michael Roth, 2021/12/14
- [PATCH 29/47] target-i386: mmu: use pg_mode instead of HF_LMA_MASK, Michael Roth, 2021/12/14
- [PATCH 30/47] target-i386: mmu: fix handling of noncanonical virtual addresses, Michael Roth, 2021/12/14
- [PATCH 02/47] target/arm: Don't skip M-profile reset entirely in user mode, Michael Roth, 2021/12/14
- [PATCH 31/47] hw/scsi/scsi-disk: MODE_PAGE_ALLS not allowed in MODE SELECT commands, Michael Roth, 2021/12/14
- [PATCH 32/47] hw: m68k: virt: Add compat machine for 6.1, Michael Roth, 2021/12/14
- [PATCH 33/47] rcu: Introduce force_rcu notifier, Michael Roth, 2021/12/14
- [PATCH 34/47] accel/tcg: Register a force_rcu notifier, Michael Roth, 2021/12/14
- [PATCH 35/47] pcie: rename 'native-hotplug' to 'x-native-hotplug', Michael Roth, 2021/12/14
- [PATCH 36/47] virtio: use virtio accessor to access packed descriptor flags, Michael Roth, 2021/12/14
- [PATCH 37/47] virtio: use virtio accessor to access packed event,
Michael Roth <=
- [PATCH 38/47] vfio: Fix memory leak of hostwin, Michael Roth, 2021/12/14
- [PATCH 39/47] nbd/server: Don't complain on certain client disconnects, Michael Roth, 2021/12/14
- [PATCH 40/47] hw/nvme: fix buffer overrun in nvme_changed_nslist (CVE-2021-3947), Michael Roth, 2021/12/14
- [PATCH 03/47] virtio-net: fix use after unmap/free for sg, Michael Roth, 2021/12/14
- [PATCH 41/47] chardev/wctable: don't free the instance in wctablet_chr_finalize, Michael Roth, 2021/12/14
- [PATCH 42/47] hw/block/fdc: Extract blk_create_empty_drive(), Michael Roth, 2021/12/14
- [PATCH 43/47] hw/block/fdc: Kludge missing floppy drive to fix CVE-2021-20196, Michael Roth, 2021/12/14
- [PATCH 44/47] tests/qtest/fdc-test: Add a regression test for CVE-2021-20196, Michael Roth, 2021/12/14
- [PATCH 45/47] virtio-blk: Fix clean up of host notifiers for single MR transaction., Michael Roth, 2021/12/14
- [PATCH 46/47] net: vmxnet3: validate configuration values during activate (CVE-2021-20203), Michael Roth, 2021/12/14