hw/net/vmxnet3: allow VMXNET3_MAX_MTU itself as a value

Currently, VMXNET3_MAX_MTU itself (being 9000) is not considered a
valid value for the MTU, but a guest running ESXi 7.0 might try to
set it and fail the assert [0].

In the Linux kernel, dev->max_mtu itself is a valid value for the MTU
and for the vmxnet3 driver it's 9000, so a guest running Linux will
also fail the assert when trying to set an MTU of 9000.

VMXNET3_MAX_MTU and s->mtu don't seem to be used in relation to buffer
allocations/accesses, so allowing the upper limit itself as a value
should be fine.

[0]: https://forum.proxmox.com/threads/114011/

Fixes: d05dcd94ae ("net: vmxnet3: validate configuration values during activate (CVE-2021-20203)")
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Fiona Ebner 2022-08-25 11:29:10 +02:00 committed by Jason Wang
parent 44c94cdb21
commit 099a638281

View File

@ -1441,7 +1441,7 @@ static void vmxnet3_activate_device(VMXNET3State *s)
vmxnet3_setup_rx_filtering(s); vmxnet3_setup_rx_filtering(s);
/* Cache fields from shared memory */ /* Cache fields from shared memory */
s->mtu = VMXNET3_READ_DRV_SHARED32(d, s->drv_shmem, devRead.misc.mtu); s->mtu = VMXNET3_READ_DRV_SHARED32(d, s->drv_shmem, devRead.misc.mtu);
assert(VMXNET3_MIN_MTU <= s->mtu && s->mtu < VMXNET3_MAX_MTU); assert(VMXNET3_MIN_MTU <= s->mtu && s->mtu <= VMXNET3_MAX_MTU);
VMW_CFPRN("MTU is %u", s->mtu); VMW_CFPRN("MTU is %u", s->mtu);
s->max_rx_frags = s->max_rx_frags =