kernel/drivers/net/hyperv/netvsc.c, branch linux-6.9.y

hv_netvsc: Don't free decrypted memory

2024-04-10T21:33:32Z

In CoCo VMs it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. The netvsc driver could free decrypted/shared pages if set_memory_decrypted() fails. Check the decrypted field in the gpadl to decide whether to free the memory. Signed-off-by: Rick Edgecombe Signed-off-by: Michael Kelley Reviewed-by: Kuppuswamy Sathyanarayanan Acked-by: Kirill A. Shutemov Link: https://lore.kernel.org/r/20240311161558.1310-4-mhklinux@outlook.com Signed-off-by: Wei Liu Message-ID: <20240311161558.1310-4-mhklinux@outlook.com>

hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove

2024-02-01T16:33:43Z

In commit ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel"), napi_disable was getting called for all channels, including all subchannels without confirming if they are enabled or not. This caused hv_netvsc getting hung at napi_disable, when netvsc_probe() has finished running but nvdev->subchan_work has not started yet. netvsc_subchan_work() -> rndis_set_subchannel() has not created the sub-channels and because of that netvsc_sc_open() is not running. netvsc_remove() calls cancel_work_sync(&nvdev->subchan_work), for which netvsc_subchan_work did not run. netif_napi_add() sets the bit NAPI_STATE_SCHED because it ensures NAPI cannot be scheduled. Then netvsc_sc_open() -> napi_enable will clear the NAPIF_STATE_SCHED bit, so it can be scheduled. napi_disable() does the opposite. Now during netvsc_device_remove(), when napi_disable is called for those subchannels, napi_disable gets stuck on infinite msleep. This fix addresses this problem by ensuring that napi_disable() is not getting called for non-enabled NAPI struct. But netif_napi_del() is still necessary for these non-enabled NAPI struct for cleanup purpose. Call trace: [ 654.559417] task:modprobe state:D stack: 0 pid: 2321 ppid: 1091 flags:0x00004002 [ 654.568030] Call Trace: [ 654.571221] [ 654.573790] __schedule+0x2d6/0x960 [ 654.577733] schedule+0x69/0xf0 [ 654.581214] schedule_timeout+0x87/0x140 [ 654.585463] ? __bpf_trace_tick_stop+0x20/0x20 [ 654.590291] msleep+0x2d/0x40 [ 654.593625] napi_disable+0x2b/0x80 [ 654.597437] netvsc_device_remove+0x8a/0x1f0 [hv_netvsc] [ 654.603935] rndis_filter_device_remove+0x194/0x1c0 [hv_netvsc] [ 654.611101] ? do_wait_intr+0xb0/0xb0 [ 654.615753] netvsc_remove+0x7c/0x120 [hv_netvsc] [ 654.621675] vmbus_remove+0x27/0x40 [hv_vmbus] Cc: stable@vger.kernel.org Fixes: ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel") Signed-off-by: Souradeep Chakrabarti Reviewed-by: Dexuan Cui Reviewed-by: Haiyang Zhang Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/1706686551-28510-1-git-send-email-schakrabarti@linux.microsoft.com Signed-off-by: Jakub Kicinski

hv_netvsc: fix netvsc_send_completion to avoid multiple message length checks

2023-10-11T08:19:01Z

The switch statement in netvsc_send_completion() is incorrectly validating the length of incoming network packets by falling through to the next case. Avoid the fallthrough. Instead break after a case match and then process the complete() call. The current code has not caused any known failures. But nonetheless, the code should be corrected as a different ordering of the switch cases might cause a length check to fail when it should not. Signed-off-by: Sonia Sharma Reviewed-by: Simon Horman Signed-off-by: David S. Miller

hv_netvsc: Remove second mapping of send and recv buffers

2023-04-17T19:19:04Z

With changes to how Hyper-V guest VMs flip memory between private (encrypted) and shared (decrypted), creating a second kernel virtual mapping for shared memory is no longer necessary. Everything needed for the transition to shared is handled by set_memory_decrypted(). As such, remove the code to create and manage the second mapping for the pre-allocated send and recv buffers. This mapping is the last user of hv_map_memory()/hv_unmap_memory(), so delete these functions as well. Finally, hv_map_memory() is the last user of vmap_pfn() in Hyper-V guest code, so remove the Kconfig selection of VMAP_PFN. Signed-off-by: Michael Kelley Reviewed-by: Tianyu Lan Link: https://lore.kernel.org/r/1679838727-87310-11-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu

hv_netvsc: Check status in SEND_RNDIS_PKT completion message

2023-02-14T12:56:56Z

Completion responses to SEND_RNDIS_PKT messages are currently processed regardless of the status in the response, so that resources associated with the request are freed. While this is appropriate, code bugs that cause sending a malformed message, or errors on the Hyper-V host, go undetected. Fix this by checking the status and outputting a rate-limited message if there is an error. Signed-off-by: Michael Kelley Reviewed-by: Haiyang Zhang Link: https://lore.kernel.org/r/1676264881-48928-1-git-send-email-mikelley@microsoft.com Signed-off-by: Paolo Abeni

hv_netvsc: Allocate memory in netvsc_dma_map() with GFP_ATOMIC

2023-02-08T04:39:26Z

Memory allocations in the network transmit path must use GFP_ATOMIC so they won't sleep. Reported-by: Paolo Abeni Link: https://lore.kernel.org/lkml/8a4d08f94d3e6fe8b6da68440eaa89a088ad84f9.camel@redhat.com/ Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver") Cc: stable@vger.kernel.org Signed-off-by: Michael Kelley Link: https://lore.kernel.org/r/1675714317-48577-1-git-send-email-mikelley@microsoft.com Signed-off-by: Jakub Kicinski

hv_netvsc: Fix missed pagebuf entries in netvsc_dma_map/unmap()

2023-02-02T08:15:30Z

netvsc_dma_map() and netvsc_dma_unmap() currently check the cp_partial flag and adjust the page_count so that pagebuf entries for the RNDIS portion of the message are skipped when it has already been copied into a send buffer. But this adjustment has already been made by code in netvsc_send(). The duplicate adjustment causes some pagebuf entries to not be mapped. In a normal VM, this doesn't break anything because the mapping doesn’t change the PFN. But in a Confidential VM, dma_map_single() does bounce buffering and provides a different PFN. Failing to do the mapping causes the wrong PFN to be passed to Hyper-V, and various errors ensue. Fix this by removing the duplicate adjustment in netvsc_dma_map() and netvsc_dma_unmap(). Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver") Cc: stable@vger.kernel.org Signed-off-by: Michael Kelley Reviewed-by: Haiyang Zhang Link: https://lore.kernel.org/r/1675135986-254490-1-git-send-email-mikelley@microsoft.com Signed-off-by: Paolo Abeni

hv_netvsc: Fix race between VF offering and VF association message from host

2022-10-07T07:43:58Z

During vm boot, there might be possibility that vf registration call comes before the vf association from host to vm. And this might break netvsc vf path, To prevent the same block vf registration until vf bind message comes from host. Cc: stable@vger.kernel.org Fixes: 00d7ddba11436 ("hv_netvsc: pair VF based on serial number") Reviewed-by: Haiyang Zhang Signed-off-by: Gaurav Kohli Signed-off-by: David S. Miller

net: drop the weight argument from netif_napi_add

2022-09-29T01:57:14Z

We tell driver developers to always pass NAPI_POLL_WEIGHT as the weight to netif_napi_add(). This may be confusing to newcomers, drop the weight argument, those who really need to tweak the weight can use netif_napi_add_weight(). Acked-by: Marc Kleine-Budde # for CAN Link: https://lore.kernel.org/r/20220927132753.750069-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

hv_netvsc: Add support for XDP_REDIRECT

2022-04-12T01:25:47Z

Handle XDP_REDIRECT action in netvsc driver. Also, transparently pass ndo_xdp_xmit to VF when available. Signed-off-by: Haiyang Zhang Link: https://lore.kernel.org/r/1649362894-20077-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Jakub Kicinski