| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
The virtio transports derives its TX credit directly from peer_buf_alloc,
which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value.
On the host side this means that the amount of data we are willing to
queue for a connection is scaled by a guest-chosen buffer size, rather
than the host's own vsock configuration. A malicious guest can advertise
a large buffer and read slowly, causing the host to allocate a
correspondingly large amount of sk_buff memory.
The same thing would happen in the guest with a malicious host, since
virtio transports share the same code base.
Introduce a small helper, virtio_transport_tx_buf_size(), that
returns min(peer_buf_alloc, buf_alloc), and use it wherever we consume
peer_buf_alloc.
This ensures the effective TX window is bounded by both the peer's
advertised buffer and our own buf_alloc (already clamped to
buffer_max_size via SO_VM_SOCKETS_BUFFER_MAX_SIZE), so a remote peer
cannot force the other to queue more data than allowed by its own
vsock settings.
On an unpatched Ubuntu 22.04 host (~64 GiB RAM), running a PoC with
32 guest vsock connections advertising 2 GiB each and reading slowly
drove Slab/SUnreclaim from ~0.5 GiB to ~57 GiB; the system only
recovered after killing the QEMU process. That said, if QEMU memory is
limited with cgroups, the maximum memory used will be limited.
With this patch applied:
Before:
MemFree: ~61.6 GiB
Slab: ~142 MiB
SUnreclaim: ~117 MiB
After 32 high-credit connections:
MemFree: ~61.5 GiB
Slab: ~178 MiB
SUnreclaim: ~152 MiB
Only ~35 MiB increase in Slab/SUnreclaim, no host OOM, and the guest
remains responsive.
Compatibility with non-virtio transports:
- VMCI uses the AF_VSOCK buffer knobs to size its queue pairs per
socket based on the local vsk->buffer_* values; the remote side
cannot enlarge those queues beyond what the local endpoint
configured.
- Hyper-V's vsock transport uses fixed-size VMBus ring buffers and
an MTU bound; there is no peer-controlled credit field comparable
to peer_buf_alloc, and the remote endpoint cannot drive in-flight
kernel memory above those ring sizes.
- The loopback path reuses virtio_transport_common.c, so it
naturally follows the same semantics as the virtio transport.
This change is limited to virtio_transport_common.c and thus affects
virtio-vsock, vhost-vsock, and loopback, bringing them in line with the
"remote window intersected with local policy" behaviour that VMCI and
Hyper-V already effectively have.
Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com>
[Stefano: small adjustments after changing the previous patch]
[Stefano: tweak the commit message]
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20260121093628.9941-4-sgarzare@redhat.com
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
The credit calculation in virtio_transport_get_credit() uses unsigned
arithmetic:
ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
If the peer shrinks its advertised buffer (peer_buf_alloc) while bytes
are in flight, the subtraction can underflow and produce a large
positive value, potentially allowing more data to be queued than the
peer can handle.
Reuse virtio_transport_has_space() which already handles this case and
add a comment to make it clear why we are doing that.
Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Melbin K Mathew <mlbnkm1@gmail.com>
[Stefano: use virtio_transport_has_space() instead of duplicating the code]
[Stefano: tweak the commit message]
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20260121093628.9941-2-sgarzare@redhat.com
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb
(with a spare tail room) is followed by a small skb (length limited by
GOOD_COPY_LEN = 128), an attempt is made to join them.
Since the introduction of MSG_ZEROCOPY support, assumption that a small skb
will always be linear is incorrect. In the zerocopy case, data is lost and
the linear skb is appended with uninitialized kernel memory.
Of all 3 supported virtio-based transports, only loopback-transport is
affected. G2H virtio-transport rx queue operates on explicitly linear skbs;
see virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G
vhost-transport may allocate non-linear skbs, but only for sizes that are
not considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in
virtio_vsock_alloc_skb().
Ensure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0
guarantees last_skb is linear.
Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260113-vsock-recv-coalescence-v2-1-552b17837cf4@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
SO_ZEROCOPY handling in vsock_connectible_setsockopt() does not get called
on accept()ed sockets due to a missing flag. Flip it.
Fixes: e0718bd82e27 ("vsock: enable setting SO_ZEROCOPY")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20251229-vsock-child-sock-custom-sockopt-v2-1-64778d6c4f88@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.18-rc7).
No conflicts, adjacent changes:
tools/testing/selftests/net/af_unix/Makefile
e1bb28bf13f4 ("selftest: af_unix: Add test for SO_PEEK_OFF.")
45a1cd8346ca ("selftests: af_unix: Add tests for ECONNRESET and EOF semantics")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
During connect(), acting on a signal/timeout by disconnecting an already
established socket leads to several issues:
1. connect() invoking vsock_transport_cancel_pkt() ->
virtio_transport_purge_skbs() may race with sendmsg() invoking
virtio_transport_get_credit(). This results in a permanently elevated
`vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling.
2. connect() resetting a connected socket's state may race with socket
being placed in a sockmap. A disconnected socket remaining in a sockmap
breaks sockmap's assumptions. And gives rise to WARNs.
3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a
transport change/drop after TCP_ESTABLISHED. Which poses a problem for
any simultaneous sendmsg() or connect() and may result in a
use-after-free/null-ptr-deref.
Do not disconnect socket on signal/timeout. Keep the logic for unconnected
sockets: they don't linger, can't be placed in a sockmap, are rejected by
sendmsg().
[1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/
[2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/
[3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20251119-vsock-interrupted-connect-v2-1-70734cf1233f@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Update all struct proto_ops connect() callback function prototypes from
"struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the
compiler about object sizes. Calls into struct proto handlers gain casts
that will be removed in the struct proto conversion patch.
No binary changes expected.
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Update all struct proto_ops bind() callback function prototypes from
"struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the
compiler about object sizes. Calls into struct proto handlers gain casts
that will be removed in the struct proto conversion patch.
No binary changes expected.
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Syzbot reported a potential lock inversion deadlock between
vsock_register_mutex and sk_lock-AF_VSOCK when vsock_linger() is called.
The issue was introduced by commit 687aa0c5581b ("vsock: Fix
transport_* TOCTOU") which added vsock_register_mutex locking in
vsock_assign_transport() around the transport->release() call, that can
call vsock_linger(). vsock_assign_transport() can be called with sk_lock
held. vsock_linger() calls sk_wait_event() that temporarily releases and
re-acquires sk_lock. During this window, if another thread hold
vsock_register_mutex while trying to acquire sk_lock, a circular
dependency is created.
Fix this by releasing vsock_register_mutex before calling
transport->release() and vsock_deassign_transport(). This is safe
because we don't need to hold vsock_register_mutex while releasing the
old transport, and we ensure the new transport won't disappear by
obtaining a module reference first via try_module_get().
Reported-by: syzbot+10e35716f8e4929681fa@syzkaller.appspotmail.com
Tested-by: syzbot+10e35716f8e4929681fa@syzkaller.appspotmail.com
Fixes: 687aa0c5581b ("vsock: Fix transport_* TOCTOU")
Cc: mhal@rbox.co
Cc: stable@vger.kernel.org
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20251021121718.137668-1-sgarzare@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- Unify guest entry code for KVM and MSHV (Sean Christopherson)
- Switch Hyper-V MSI domain to use msi_create_parent_irq_domain()
(Nam Cao)
- Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV
(Mukesh Rathor)
- Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov)
- Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna
Kumar T S M)
- Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari,
Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley)
* tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
hyperv: Remove the spurious null directive line
MAINTAINERS: Mark hyperv_fb driver Obsolete
fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver
Drivers: hv: Make CONFIG_HYPERV bool
Drivers: hv: Add CONFIG_HYPERV_VMBUS option
Drivers: hv: vmbus: Fix typos in vmbus_drv.c
Drivers: hv: vmbus: Fix sysfs output format for ring buffer index
Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()
x86/hyperv: Switch to msi_create_parent_irq_domain()
mshv: Use common "entry virt" APIs to do work in root before running guest
entry: Rename "kvm" entry code assets to "virt" to genericize APIs
entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper
mshv: Handle NEED_RESCHED_LAZY before transferring to guest
x86/hyperv: Add kexec/kdump support on Azure CVMs
Drivers: hv: Simplify data structures for VMBus channel close message
Drivers: hv: util: Cosmetic changes for hv_utils_transport.c
mshv: Add support for a new parent partition configuration
clocksource: hyper-v: Skip unnecessary checks for the root partition
hyperv: Add missing field to hv_output_map_device_interrupt
|
|
At present VMBus driver is hinged off of CONFIG_HYPERV which entails
lot of builtin code and encompasses too much. It's not always clear
what depends on builtin hv code and what depends on VMBus. Setting
CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin
adds even more confusion. VMBus is an independent module and should have
its own config option. Also, there are scenarios like baremetal dom0/root
where support is built in with CONFIG_HYPERV but without VMBus. Lastly,
there are more features coming down that use CONFIG_HYPERV and add more
dependencies on it.
So, create a fine grained HYPERV_VMBUS option and update Kconfigs for
dependency on VMBus.
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci
Signed-off-by: Wei Liu <wei.liu@kernel.org>
|
|
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This change adds a new WQ_PERCPU flag at the network subsystem, to explicitly
request the use of the per-CPU behavior. Both flags coexist for one release
cycle to allow callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
All existing users have been updated accordingly.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20250918142427.309519-4-marco.crivellari@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20250918142427.309519-3-marco.crivellari@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.17-rc4).
No conflicts.
Adjacent changes:
drivers/net/ethernet/intel/idpf/idpf_txrx.c
02614eee26fb ("idpf: do not linearize big TSO packets")
6c4e68480238 ("idpf: remove obsolete stashing code")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Commit 6693731487a8 ("vsock/virtio: Allocate nonlinear SKBs for handling
large transmit buffers") converted the virtio vsock transmit path to
utilise nonlinear SKBs when handling large buffers. As part of this
change, virtio_transport_fill_skb() was updated to call
skb_copy_datagram_from_iter() instead of memcpy_from_msg() as the latter
expects a single destination buffer and cannot handle nonlinear SKBs
correctly.
Unfortunately, during this conversion, I overlooked the error case when
the copying function returns -EFAULT due to a fault on the input buffer
in userspace. In this case, memcpy_from_msg() reverts the iterator to
its initial state thanks to copy_from_iter_full() whereas
skb_copy_datagram_from_iter() leaves the iterator partially advanced.
This results in a WARN_ONCE() from the vsock code, which expects the
iterator to stay in sync with the number of bytes transmitted so that
virtio_transport_send_pkt_info() can return -EFAULT when it is called
again:
------------[ cut here ]------------
'send_pkt()' returns 0, but 65536 expected
WARNING: CPU: 0 PID: 5503 at net/vmw_vsock/virtio_transport_common.c:428 virtio_transport_send_pkt_info+0xd11/0xf00 net/vmw_vsock/virtio_transport_common.c:426
Modules linked in:
CPU: 0 UID: 0 PID: 5503 Comm: syz.0.17 Not tainted 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call virtio_transport_fill_skb_full() to restore the previous iterator
behaviour.
Cc: Jason Wang <jasowang@redhat.com>
Cc: Stefano Garzarella <sgarzare@redhat.com>
Fixes: 6693731487a8 ("vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers")
Reported-by: syzbot+b4d960daf7a3c7c2b7b1@syzkaller.appspotmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20250818180355.29275-3-will@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.17-rc2).
No conflicts.
Adjacent changes:
drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
d7a276a5768f ("net: stmmac: rk: convert to suspend()/resume() methods")
de1e963ad064 ("net: stmmac: rk: put the PHY clock on remove")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Previous commit 230b183921ec ("net: Use standard structures for generic
socket address structures.") use 'struct sockaddr_storage address;'
to replace 'char address[MAX_SOCK_ADDR];'.
The macro MAX_SOCK_ADDR is removed by commit 01893c82b4e6 ("net: Remove
MAX_SOCK_ADDR constant").
The comment in vsock_getname() is outdated, use sizeof(struct
sockaddr_storage) instead of magic value 128.
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Link: https://patch.msgid.link/20250812015929.1419896-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can
cause a use-after-free when a connection is made to the bound socket.
The socket returned by accept() also has port VMADDR_PORT_ANY but is not
on the list of unbound sockets. Binding it will result in an extra
refcount decrement similar to the one fixed in fcdd2242c023 (vsock: Keep
the binding until socket destruction).
Modify the check in __vsock_bind_connectible() to also prevent binding
to VMADDR_PORT_ANY.
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250807041811.678-1-markovicbudimir@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Pull virtio updates from Michael Tsirkin:
- vhost can now support legacy threading if enabled in Kconfig
- vsock memory allocation strategies for large buffers have been
improved, reducing pressure on kmalloc
- vhost now supports the in-order feature. guest bits missed the merge
window.
- fixes, cleanups all over the place
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (30 commits)
vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers
vsock/virtio: Rename virtio_vsock_skb_rx_put()
vhost/vsock: Allocate nonlinear SKBs for handling large receive buffers
vsock/virtio: Move SKB allocation lower-bound check to callers
vsock/virtio: Rename virtio_vsock_alloc_skb()
vsock/virtio: Resize receive buffers so that each SKB fits in a 4K page
vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put()
vsock/virtio: Validate length in packet header before skb_put()
vhost/vsock: Avoid allocating arbitrarily-sized SKBs
vhost_net: basic in_order support
vhost: basic in order support
vhost: fail early when __vhost_add_used() fails
vhost: Reintroduce kthread API and add mode selection
vdpa: Fix IDR memory leak in VDUSE module exit
vdpa/mlx5: Fix release of uninitialized resources on error path
vhost-scsi: Fix check for inline_sg_cnt exceeding preallocated limit
virtio: virtio_dma_buf: fix missing parameter documentation
vhost: Fix typos
vhost: vringh: Remove unused functions
vhost: vringh: Remove unused iotlb functions
...
|
|
When transmitting a vsock packet, virtio_transport_send_pkt_info() calls
virtio_transport_alloc_linear_skb() to allocate and fill SKBs with the
transmit data. Unfortunately, these are always linear allocations and
can therefore result in significant pressure on kmalloc() considering
that the maximum packet size (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE +
VIRTIO_VSOCK_SKB_HEADROOM) is a little over 64KiB, resulting in a 128KiB
allocation for each packet.
Rework the vsock SKB allocation so that, for sizes with page order
greater than PAGE_ALLOC_COSTLY_ORDER, a nonlinear SKB is allocated
instead with the packet header in the SKB and the transmit data in the
fragments. Note that this affects both the vhost and virtio transports.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-10-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
In preparation for using virtio_vsock_skb_rx_put() when populating SKBs
on the vsock TX path, rename virtio_vsock_skb_rx_put() to
virtio_vsock_skb_put().
No functional change.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-9-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
In preparation for nonlinear allocations for large SKBs, rename
virtio_vsock_alloc_skb() to virtio_vsock_alloc_linear_skb() to indicate
that it returns linear SKBs unconditionally and switch all callers over
to this new interface for now.
No functional change.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-6-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
When allocating receive buffers for the vsock virtio RX virtqueue, an
SKB is allocated with a 4140 data payload (the 44-byte packet header +
VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE). Even when factoring in the SKB
overhead, the resulting 8KiB allocation thanks to the rounding in
kmalloc_reserve() is wasteful (~3700 unusable bytes) and results in a
higher-order page allocation on systems with 4KiB pages just for the
sake of a few hundred bytes of packet data.
Limit the vsock virtio RX buffers to 4KiB per SKB, resulting in much
better memory utilisation and removing the need to allocate higher-order
pages entirely.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-5-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
virtio_vsock_skb_rx_put() only calls skb_put() if the length in the
packet header is not zero even though skb_put() handles this case
gracefully.
Remove the functionally redundant check from virtio_vsock_skb_rx_put()
and, on the assumption that this is a worthwhile optimisation for
handling credit messages, augment the existing length checks in
virtio_transport_rx_work() to elide the call for zero-length payloads.
Since the callers all have the length, extend virtio_vsock_skb_rx_put()
to take it as an additional parameter rather than fish it back out of
the packet header.
Note that the vhost code already has similar logic in
vhost_vsock_alloc_skb().
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-4-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
When receiving a vsock packet in the guest, only the virtqueue buffer
size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately,
virtio_vsock_skb_rx_put() uses the length from the packet header as the
length argument to skb_put(), potentially resulting in SKB overflow if
the host has gone wonky.
Validate the length as advertised by the packet header before calling
virtio_vsock_skb_rx_put().
Cc: <stable@vger.kernel.org>
Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-3-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
|
|
The local variable 'vm_addr' is always not NULL, no need to check it.
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250725013808.337924-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.16-rc6).
No conflicts.
Adjacent changes:
Documentation/devicetree/bindings/net/allwinner,sun8i-a83t-emac.yaml
0a12c435a1d6 ("dt-bindings: net: sun8i-emac: Add A100 EMAC compatible")
b3603c0466a8 ("dt-bindings: net: sun8i-emac: Rename A523 EMAC0 to GMAC0")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Add support for SIOCINQ ioctl, indicating the length of bytes unread in the
socket. The value is obtained from `vsock_stream_has_data()`.
Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20250708-siocinq-v6-2-3775f9a9e359@antgroup.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
When hv_sock was originally added, __vsock_stream_recvmsg() and
vsock_stream_has_data() actually only needed to know whether there
is any readable data or not, so hvs_stream_has_data() was written to
return 1 or 0 for simplicity.
However, now hvs_stream_has_data() should return the readable bytes
because vsock_data_ready() -> vsock_stream_has_data() needs to know the
actual bytes rather than a boolean value of 1 or 0.
The SIOCINQ ioctl support also needs hvs_stream_has_data() to return
the readable bytes.
Let hvs_stream_has_data() return the readable bytes of the payload in
the next host-to-guest VMBus hv_sock packet.
Note: there may be multiple incoming hv_sock packets pending in the
VMBus channel's ringbuffer, but so far there is not a VMBus API that
allows us to know all the readable bytes in total without reading and
caching the payload of the multiple packets, so let's just return the
readable bytes of the next single packet. In the future, we'll either
add a VMBus API that allows us to know the total readable bytes without
touching the data in the ringbuffer, or the hv_sock driver needs to
understand the VMBus packet format and parse the packets directly.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://patch.msgid.link/20250708-siocinq-v6-1-3775f9a9e359@antgroup.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Support returning VMADDR_CID_LOCAL in case no other vsock transport is
available.
Fixes: 0e12190578d0 ("vsock: add local transport support in the vsock core")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-3-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Transport assignment may race with module unload. Protect new_transport
from becoming a stale pointer.
This also takes care of an insecure call in vsock_use_local_transport();
add a lockdep assert.
BUG: unable to handle page fault for address: fffffbfff8056000
Oops: Oops: 0000 [#1] SMP KASAN
RIP: 0010:vsock_assign_transport+0x366/0x600
Call Trace:
vsock_connect+0x59c/0xc40
__sys_connect+0xe8/0x100
__x64_sys_connect+0x6e/0xc0
do_syscall_64+0x92/0x1c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-2-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
vsock_find_cid() and vsock_dev_do_ioctl() may race with module unload.
transport_{g2h,h2g} may become NULL after the NULL check.
Introduce vsock_transport_local_cid() to protect from a potential
null-ptr-deref.
KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
RIP: 0010:vsock_find_cid+0x47/0x90
Call Trace:
__vsock_bind+0x4b2/0x720
vsock_bind+0x90/0xe0
__sys_bind+0x14d/0x1e0
__x64_sys_bind+0x6e/0xc0
do_syscall_64+0x92/0x1c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
RIP: 0010:vsock_dev_do_ioctl.isra.0+0x58/0xf0
Call Trace:
__x64_sys_ioctl+0x12d/0x190
do_syscall_64+0x92/0x1c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250703-vsock-transports-toctou-v4-1-98f0eb530747@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
In vmci_transport_packet_init memset the vmci_transport_packet before
populating the fields to avoid any uninitialised data being left in the
structure.
Cc: Bryan Tan <bryan-bt.tan@broadcom.com>
Cc: Vishnu Dasa <vishnu.dasa@broadcom.com>
Cc: Broadcom internal kernel review list
Cc: Stefano Garzarella <sgarzare@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: virtualization@lists.linux.dev
Cc: netdev@vger.kernel.org
Cc: stable <stable@kernel.org>
Signed-off-by: HarshaVardhana S A <harshavardhana.sa@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250701122254.2397440-1-gregkh@linuxfoundation.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Merge in late fixes to prepare for the 6.16 net-next PR.
No conflicts nor adjacent changes.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Lingering should be transport-independent in the long run. In preparation
for supporting other transports, as well as the linger on shutdown(), move
code to core.
Generalize by querying vsock_transport::unsent_bytes(), guard against the
callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
SOCK_LINGER check into vsock_linger().
Flatten the function. Remove the nested block by inverting the condition:
return early on !timeout.
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250522-vsock-linger-v6-2-2ad00b0e447e@rbox.co
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Currently vsock's lingering effectively boils down to waiting (or timing
out) until packets are consumed or dropped by the peer; be it by receiving
the data, closing or shutting down the connection.
To align with the semantics described in the SO_LINGER section of man
socket(7) and to mimic AF_INET's behaviour more closely, change the logic
of a lingering close(): instead of waiting for all data to be handled,
block until data is considered sent from the vsock's transport point of
view. That is until worker picks the packets for processing and decrements
virtio_vsock_sock::bytes_unsent down to 0.
Note that (some interpretation of) lingering was always limited to
transports that called virtio_transport_wait_close() on transport release.
This does not change, i.e. under Hyper-V and VMCI no lingering would be
observed.
The implementation does not adhere strictly to man page's interpretation of
SO_LINGER: shutdown() will not trigger the lingering. This follows AF_INET.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250522-vsock-linger-v6-1-2ad00b0e447e@rbox.co
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
In `struct virtio_vsock_sock`, we maintain two counters:
- `rx_bytes`: used internally to track how many bytes have been read.
This supports mechanisms like .stream_has_data() and sock_rcvlowat().
- `fwd_cnt`: used for the credit mechanism to inform available receive
buffer space to the remote peer.
These counters are updated via virtio_transport_inc_rx_pkt() and
virtio_transport_dec_rx_pkt().
Since the beginning with commit 06a8fc78367d ("VSOCK: Introduce
virtio_vsock_common.ko"), we call virtio_transport_dec_rx_pkt() in
virtio_transport_stream_do_dequeue() only when we consume the entire
packet, so partial reads, do not update `rx_bytes` and `fwd_cnt`.
This is fine for `fwd_cnt`, because we still have space used for the
entire packet, and we don't want to update the credit for the other
peer until we free the space of the entire packet. However, this
causes `rx_bytes` to be stale on partial reads.
Previously, this didn’t cause issues because `rx_bytes` was used only by
.stream_has_data(), and any unread portion of a packet implied data was
still available. However, since commit 93b808876682
("virtio/vsock: fix logic which reduces credit update messages"), we now
rely on `rx_bytes` to determine if a credit update should be sent when
the data in the RX queue drops below SO_RCVLOWAT value.
This patch fixes the accounting by updating `rx_bytes` with the number
of bytes actually read, even on partial reads, while leaving `fwd_cnt`
untouched until the packet is fully consumed. Also introduce a new
`buf_used` counter to check that the remote peer is honoring the given
credit; this was previously done via `rx_bytes`.
Fixes: 93b808876682 ("virtio/vsock: fix logic which reduces credit update messages")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250521121705.196379-1-sgarzare@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Augment dmabuf binding to be able to handle TX. Additional to all the RX
binding, we also create tx_vec needed for the TX path.
Provide API for sendmsg to be able to send dmabufs bound to this device:
- Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from.
- MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf.
Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY
implementation, while disabling instances where MSG_ZEROCOPY falls back
to copying.
We additionally pipe the binding down to the new
zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems
instead of the traditional page netmems.
We also special case skb_frag_dma_map to return the dma-address of these
dmabuf net_iovs instead of attempting to map pages.
The TX path may release the dmabuf in a context where we cannot wait.
This happens when the user unbinds a TX dmabuf while there are still
references to its netmems in the TX path. In that case, the netmems will
be put_netmem'd from a context where we can't unmap the dmabuf, Resolve
this by making __net_devmem_dmabuf_binding_free schedule_work'd.
Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat
of the implementation came from devmem TCP RFC v1[1], which included the
TX path, but Stan did all the rebasing on top of netmem/net_iov.
Cc: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
When a peer attempts to establish a connection, vsock_connect() contains
a loop that waits for the state to be TCP_ESTABLISHED. However, the
other peer can be fast enough to accept the connection and close it
immediately, thus moving the state to TCP_CLOSING.
When this happens, the peer in the vsock_connect() is properly woken up,
but since the state is not TCP_ESTABLISHED, it goes back to sleep
until the timeout expires, returning -ETIMEDOUT.
If the socket state is TCP_CLOSING, waiting for the timeout is pointless.
vsock_connect() can return immediately without errors or delay since the
connection actually happened. The socket will be in a closing state,
but this is not an issue, and subsequent calls will fail as expected.
We discovered this issue while developing a test that accepts and
immediately closes connections to stress the transport switch between
two connect() calls, where the first one was interrupted by a signal
(see Closes link).
Reported-by: Luigi Leonardi <leonardi@redhat.com>
Closes: https://lore.kernel.org/virtualization/bq6hxrolno2vmtqwcvb5bljfpb7mvwb3kohrvaed6auz5vxrfv@ijmd2f3grobn/
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Luigi Leonardi <leonardi@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20250328141528.420719-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
In the spirit of commit 91751e248256 ("vsock: prevent null-ptr-deref in
vsock_*[has_data|has_space]"), armorize the "impossible" cases with a
warning.
Fixes: 634f1a7110b4 ("vsock: support sockmap")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
When executing suspend to ram twice in a row,
the `rx_buf_nr` and `rx_buf_max_nr` increase to three times vq->num_free.
Then after virtqueue_get_buf and `rx_buf_nr` decreased
in function virtio_transport_rx_work,
the condition to fill rx buffer
(rx_buf_nr < rx_buf_max_nr / 2) will never be met.
It is because that `rx_buf_nr` and `rx_buf_max_nr`
are initialized only in virtio_vsock_probe(),
but they should be reset whenever virtqueues are recreated,
like after a suspend/resume.
Move the `rx_buf_nr` and `rx_buf_max_nr` initialization in
virtio_vsock_vqs_init(), so we are sure that they are properly
initialized, every time we initialize the virtqueues, either when we
load the driver or after a suspend/resume.
To prevent erroneous atomic load operations on the `queued_replies`
in the virtio_transport_send_pkt_work() function
which may disrupt the scheduling of vsock->rx_work
when transmitting reply-required socket packets,
this atomic variable must undergo synchronized initialization
alongside the preceding two variables after a suspend/resume.
Fixes: bd50c5dc182b ("vsock/virtio: add support for device suspend/resume")
Link: https://lore.kernel.org/virtualization/20250207052033.2222629-1-junnan01.wu@samsung.com/
Co-developed-by: Ying Gao <ying01.gao@samsung.com>
Signed-off-by: Ying Gao <ying01.gao@samsung.com>
Signed-off-by: Junnan Wu <junnan01.wu@samsung.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20250214012200.1883896-1-junnan01.wu@samsung.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
During socket release, sock_orphan() is called without considering that it
sets sk->sk_wq to NULL. Later, if SO_LINGER is enabled, this leads to a
null pointer dereferenced in virtio_transport_wait_close().
Orphan the socket only after transport release.
Partially reverts the 'Fixes:' commit.
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
lock_acquire+0x19e/0x500
_raw_spin_lock_irqsave+0x47/0x70
add_wait_queue+0x46/0x230
virtio_transport_release+0x4e7/0x7f0
__vsock_release+0xfd/0x490
vsock_release+0x90/0x120
__sock_release+0xa3/0x250
sock_close+0x14/0x20
__fput+0x35e/0xa90
__x64_sys_close+0x78/0xd0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Reported-by: syzbot+9d55b199192a4be7d02c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9d55b199192a4be7d02c
Fixes: fcdd2242c023 ("vsock: Keep the binding until socket destruction")
Tested-by: Luigi Leonardi <leonardi@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250210-vsock-linger-nullderef-v3-1-ef6244d02b54@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
