kernel/linux.git/drivers/bluetooth/virtio_bt.c, branch v6.6.148

Bluetooth: virtio_bt: validate rx pkt_type header length

2026-05-17T15:13:38+00:00

commit daf23014e5d975e72ea9c02b5160d3fcf070ea47 upstream. virtbt_rx_handle() reads the leading pkt_type byte from the RX skb and forwards the remainder to hci_recv_frame() for every event/ACL/SCO/ISO type, without checking that the remaining payload is at least the fixed HCI header for that type. After the preceding patch bounds the backend-supplied used.len to [1, VIRTBT_RX_BUF_SIZE], a one-byte completion still reaches hci_recv_frame() with skb->len already pulled to 0. If the byte happened to be HCI_ACLDATA_PKT, the ACL-vs-ISO classification fast-path in hci_dev_classify_pkt_type() dereferences hci_acl_hdr(skb)->handle whenever the HCI device has an active CIS_LINK, BIS_LINK, or PA_LINK connection, reading two bytes of uninitialized RX-buffer data. The same hazard exists for every packet type the driver accepts because none of the switch cases in virtbt_rx_handle() check skb->len against the per-type minimum HCI header size before handing the frame to the core. After stripping pkt_type, require skb->len to cover the fixed header size for the selected type (event 2, ACL 4, SCO 3, ISO 4) before calling hci_recv_frame(); drop ratelimited otherwise. Unknown pkt_type values still take the original kfree_skb() default path. Use bt_dev_err_ratelimited() because both the length and pkt_type values come from an untrusted backend that can otherwise flood the kernel log. Fixes: 160fbcf3bfb9 ("Bluetooth: virtio_bt: Use skb_put to set length") Cc: stable@vger.kernel.org Cc: Soenke Huster Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: virtio_bt: clamp rx length before skb_put

2026-05-17T15:13:38+00:00

commit 21bd244b6de5d2fe1063c23acc93fbdd2b20d112 upstream. virtbt_rx_work() calls skb_put(skb, len) where len comes directly from virtqueue_get_buf() with no validation against the buffer we posted to the device. The RX skb is allocated in virtbt_add_inbuf() and exposed to virtio as exactly 1000 bytes via sg_init_one(). Checking len against skb_tailroom(skb) is not sufficient because alloc_skb() can leave more tailroom than the 1000 bytes actually handed to the device. A malicious or buggy backend can therefore report used.len between 1001 and skb_tailroom(skb), causing skb_put() to include uninitialized kernel heap bytes that were never written by the device. The same path also accepts len == 0, in which case skb_put(skb, 0) leaves the skb empty but virtbt_rx_handle() still reads the pkt_type byte from skb->data, consuming uninitialized memory. Define VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and sg_init_one(), and gate virtbt_rx_work() on that same constant so the bound checked matches the buffer actually exposed to the device. Reject used.len == 0 in the same gate so an empty completion can no longer reach virtbt_rx_handle(). Use bt_dev_err_ratelimited() because the length value comes from an untrusted backend that can otherwise flood the kernel log. Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened the USB 9p transport against unchecked device-reported length. Fixes: 160fbcf3bfb9 ("Bluetooth: virtio_bt: Use skb_put to set length") Cc: stable@vger.kernel.org Cc: Soenke Huster Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: HCI: Remove HCI_AMP support

2024-06-12T09:11:55+00:00

[ Upstream commit 84a4bb6548a29326564f0e659fb8064503ecc1c7 ] Since BT_HS has been remove HCI_AMP controllers no longer has any use so remove it along with the capability of creating AMP controllers. Since we no longer need to differentiate between AMP and Primary controllers, as only HCI_PRIMARY is left, this also remove hdev->dev_type altogether. Fixes: e7b02296fb40 ("Bluetooth: Remove BT_HS") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

virtio_bt: call scheduler when we free unused buffs

2023-07-03T16:15:12+00:00

For virtio-net we were getting CPU stall warnings, and fixed it by calling the scheduler: see f8bb51043945 ("virtio_net: suppress cpu stall when free_unused_bufs"). This driver is similar so theoretically the same logic applies. Signed-off-by: Xianting Tian Message-Id: <20230609131817.712867-4-xianting.tian@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin

virtio_bt: Fix alignment in configuration struct

2022-12-12T22:19:23+00:00

The current version of the configuration structure has unaligned 16-bit fields, but according to the specification [1], access to the configuration space must be aligned. Add a second, aligned version of the configuration structure and a new feature bit indicating that this version is being used. [1] https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.pdf Signed-off-by: Igor Skalkin Signed-off-by: Luiz Augusto von Dentz

Bluetooth: virtio_bt: fix device removal

2022-12-12T22:19:23+00:00

Device removal is clearly out of virtio spec: it attempts to remove unused buffers from a VQ before invoking device reset. To fix, make open/close NOPs and do all cleanup/setup in probe/remove. NB: This is a hacky way to handle this - virtbt_{open,close} as NOP is not really what a driver is supposed to be doing. These are transport enable/disable callbacks from the BT core towards the driver. It maps to a device being enabled/disabled by something like bluetoothd for example. So if disabled, users expect that no resources/queues are in use. It does work with all other transports like USB, SDIO, UART etc. There should be no buffer used if the device is powered off. We also don’t have any USB URBs in-flight if the transport is not active. The way to implement a proper fix would be using vq reset if supported, or even using a full device reset. The cost of the hack is a single skb wasted on an unused bt device. NB2: with this fix in place driver still suffers from a race condition if an interrupt triggers while device is being reset. To fix, in the virtbt_close() callback we should deactivate all interrupts. To be fixed. squashed fixup: bluetooth: virtio_bt: fix an error code in probe() Signed-off-by: Dan Carpenter Reported-by: Hulk Robot Signed-off-by: Yang Yingliang Signed-off-by: Michael S. Tsirkin Message-Id: <20220811080943.198245-1-mst@redhat.com> Signed-off-by: Luiz Augusto von Dentz Tested-by: Igor Skalkin

Bluetooth: virtio_bt: Use skb_put to set length

2022-11-02T21:15:42+00:00

By using skb_put we ensure that skb->tail is set correctly. Currently, skb->tail is always zero, which leads to errors, such as the following page fault in rfcomm_recv_frame: BUG: unable to handle page fault for address: ffffed1021de29ff #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:rfcomm_run+0x831/0x4040 (net/bluetooth/rfcomm/core.c:1751) Fixes: afd2daa26c7a ("Bluetooth: Add support for virtio transport driver") Signed-off-by: Soenke Huster Signed-off-by: Luiz Augusto von Dentz

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2022-01-18T08:05:48+00:00

Pull virtio updates from Michael Tsirkin: "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes. - partial support for < MAX_ORDER - 1 granularity for virtio-mem - driver_override for vdpa - sysfs ABI documentation for vdpa - multiqueue config support for mlx5 vdpa - and misc fixes, cleanups" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits) vdpa/mlx5: Fix tracking of current number of VQs vdpa/mlx5: Fix is_index_valid() to refer to features vdpa: Protect vdpa reset with cf_mutex vdpa: Avoid taking cf_mutex lock on get status vdpa/vdpa_sim_net: Report max device capabilities vdpa: Use BIT_ULL for bit operations vdpa/vdpa_sim: Configure max supported virtqueues vdpa/mlx5: Report max device capabilities vdpa: Support reporting max device capabilities vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps() vdpa: Add support for returning device configuration information vdpa/mlx5: Support configuring max data virtqueue vdpa/mlx5: Fix config_attr_mask assignment vdpa: Allow to configure max data virtqueues vdpa: Read device configuration only if FEATURES_OK vdpa: Sync calls set/get config/status with cf_mutex vdpa/mlx5: Distribute RX virtqueues in RQT object vdpa: Provide interface to read driver features vdpa: clean up get_config_size ret value handling virtio_ring: mark ring unused on error ...

virtio: wrap config->reset calls

2022-01-14T23:50:52+00:00

This will enable cleanups down the road. The idea is to disable cbs, then add "flush_queued_cbs" callback as a parameter, this way drivers can flush any work queued after callbacks have been disabled. Signed-off-by: Michael S. Tsirkin Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com Signed-off-by: Michael S. Tsirkin

Bluetooth: virtio_bt: fix memory leak in virtbt_rx_handle()

2021-10-20T12:58:46+00:00

On the reception of packets with an invalid packet type, the memory of the allocated socket buffers is never freed. Add a default case that frees these to avoid a memory leak. Fixes: afd2daa26c7a ("Bluetooth: Add support for virtio transport driver") Signed-off-by: Soenke Huster Signed-off-by: Marcel Holtmann