kernel/linux.git/drivers/hv, branch v6.1.87

Drivers: hv: vmbus: Don't dereference ACPI root object handle

2023-09-13T07:42:59+00:00

[ Upstream commit 78e04bbff849b51b56f5925b1945db2c6e128b61 ] Since the commit referenced in the Fixes: tag below the VMBus client driver is walking the ACPI namespace up from the VMBus ACPI device to the ACPI namespace root object trying to find Hyper-V MMIO ranges. However, if it is not able to find them it ends trying to walk resources of the ACPI namespace root object itself. This object has all-ones handle, which causes a NULL pointer dereference in the ACPI code (from dereferencing this pointer with an offset). This in turn causes an oops on boot with VMBus host implementations that do not provide Hyper-V MMIO ranges in their VMBus ACPI device or its ancestors. The QEMU VMBus implementation is an example of such implementation. I guess providing these ranges is optional, since all tested Windows versions seem to be able to use VMBus devices without them. Fix this by explicitly terminating the lookup at the ACPI namespace root object. Note that Linux guests under KVM/QEMU do not use the Hyper-V PV interface by default - they only do so if the KVM PV interface is missing or disabled. Example stack trace of such oops: [ 3.710827] ? __die+0x1f/0x60 [ 3.715030] ? page_fault_oops+0x159/0x460 [ 3.716008] ? exc_page_fault+0x73/0x170 [ 3.716959] ? asm_exc_page_fault+0x22/0x30 [ 3.717957] ? acpi_ns_lookup+0x7a/0x4b0 [ 3.718898] ? acpi_ns_internalize_name+0x79/0xc0 [ 3.720018] acpi_ns_get_node_unlocked+0xb5/0xe0 [ 3.721120] ? acpi_ns_check_object_type+0xfe/0x200 [ 3.722285] ? acpi_rs_convert_aml_to_resource+0x37/0x6e0 [ 3.723559] ? down_timeout+0x3a/0x60 [ 3.724455] ? acpi_ns_get_node+0x3a/0x60 [ 3.725412] acpi_ns_get_node+0x3a/0x60 [ 3.726335] acpi_ns_evaluate+0x1c3/0x2c0 [ 3.727295] acpi_ut_evaluate_object+0x64/0x1b0 [ 3.728400] acpi_rs_get_method_data+0x2b/0x70 [ 3.729476] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus] [ 3.730940] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus] [ 3.732411] acpi_walk_resources+0x78/0xd0 [ 3.733398] vmbus_platform_driver_probe+0x9f/0x1d0 [hv_vmbus] [ 3.734802] platform_probe+0x3d/0x90 [ 3.735684] really_probe+0x19b/0x400 [ 3.736570] ? __device_attach_driver+0x100/0x100 [ 3.737697] __driver_probe_device+0x78/0x160 [ 3.738746] driver_probe_device+0x1f/0x90 [ 3.739743] __driver_attach+0xc2/0x1b0 [ 3.740671] bus_for_each_dev+0x70/0xc0 [ 3.741601] bus_add_driver+0x10e/0x210 [ 3.742527] driver_register+0x55/0xf0 [ 3.744412] ? 0xffffffffc039a000 [ 3.745207] hv_acpi_init+0x3c/0x1000 [hv_vmbus] Fixes: 7f163a6fd957 ("drivers:hv: Modify hv_vmbus to search for all MMIO ranges available.") Signed-off-by: Maciej S. Szmigiero Reviewed-by: Michael Kelley Signed-off-by: Wei Liu Link: https://lore.kernel.org/r/fd8e64ceeecfd1d95ff49021080cf699e88dbbde.1691606267.git.maciej.szmigiero@oracle.com Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Fix vmbus_wait_for_unload() to scan present CPUs

2023-06-28T09:12:23+00:00

commit 320805ab61e5f1e2a5729ae266e16bec2904050c upstream. vmbus_wait_for_unload() may be called in the panic path after other CPUs are stopped. vmbus_wait_for_unload() currently loops through online CPUs looking for the UNLOAD response message. But the values of CONFIG_KEXEC_CORE and crash_kexec_post_notifiers affect the path used to stop the other CPUs, and in one of the paths the stopped CPUs are removed from cpu_online_mask. This removal happens in both x86/x64 and arm64 architectures. In such a case, vmbus_wait_for_unload() only checks the panic'ing CPU, and misses the UNLOAD response message except when the panic'ing CPU is CPU 0. vmbus_wait_for_unload() eventually times out, but only after waiting 100 seconds. Fix this by looping through *present* CPUs in vmbus_wait_for_unload(). The cpu_present_mask is not modified by stopping the other CPUs in the panic path, nor should it be. Also, in a CoCo VM the synic_message_page is not allocated in hv_synic_alloc(), but is set and cleared in hv_synic_enable_regs() and hv_synic_disable_regs() such that it is set only when the CPU is online. If not all present CPUs are online when vmbus_wait_for_unload() is called, the synic_message_page might be NULL. Add a check for this. Fixes: cd95aad55793 ("Drivers: hv: vmbus: handle various crash scenarios") Cc: stable@vger.kernel.org Reported-by: John Starks Signed-off-by: Michael Kelley Reviewed-by: Vitaly Kuznetsov Link: https://lore.kernel.org/r/1684422832-38476-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Call hv_synic_free() if hv_synic_alloc() fails

2023-06-28T09:12:23+00:00

commit ec97e112985c2581ee61854a4b74f080f6cdfc2c upstream. Commit 572086325ce9 ("Drivers: hv: vmbus: Cleanup synic memory free path") says "Any memory allocations that succeeded will be freed when the caller cleans up by calling hv_synic_free()", but if the get_zeroed_page() in hv_synic_alloc() fails, currently hv_synic_free() is not really called in vmbus_bus_init(), consequently there will be a memory leak, e.g. hv_context.hv_numa_map is not freed in the error path. Fix this by updating the goto labels. Cc: stable@kernel.org Signed-off-by: Dexuan Cui Fixes: 4df4cb9e99f8 ("x86/hyperv: Initialize clockevents earlier in CPU onlining") Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20230504224155.10484-1-decui@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

Drivers: vmbus: Check for channel allocation before looking up relids

2023-04-13T14:55:18+00:00

[ Upstream commit 1eb65c8687316c65140b48fad27133d583178e15 ] relid2channel() assumes vmbus channel array to be allocated when called. However, in cases such as kdump/kexec, not all relids will be reset by the host. When the second kernel boots and if the guest receives a vmbus interrupt during vmbus driver initialization before vmbus_connect() is called, before it finishes, or if it fails, the vmbus interrupt service routine is called which in turn calls relid2channel() and can cause a null pointer dereference. Print a warning and error out in relid2channel() for a channel id that's invalid in the second kernel. Fixes: 8b6a877c060e ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels") Signed-off-by: Mohammed Gamal Reviewed-by: Dexuan Cui Link: https://lore.kernel.org/r/20230217204411.212709-1-mgamal@redhat.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin

HV: hv_balloon: fix memory leak with using debugfs_lookup()

2023-02-09T10:28:21+00:00

commit 6dfb0771429a63db8561d44147f2bb76f93e1c86 upstream. When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Wei Liu Cc: Dexuan Cui Fixes: d180e0a1be6c ("Drivers: hv: Create debugfs file with hyper-v balloon usage information") Cc: stable Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20230202140918.2289522-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

video: hyperv_fb: Avoid taking busy spinlock on panic path

2022-12-31T12:32:56+00:00

[ Upstream commit 1d044ca035dc22df0d3b39e56f2881071d9118bd ] The Hyper-V framebuffer code registers a panic notifier in order to try updating its fbdev if the kernel crashed. The notifier callback is straightforward, but it calls the vmbus_sendpacket() routine eventually, and such function takes a spinlock for the ring buffer operations. Panic path runs in atomic context, with local interrupts and preemption disabled, and all secondary CPUs shutdown. That said, taking a spinlock might cause a lockup if a secondary CPU was disabled with such lock taken. Fix it here by checking if the ring buffer spinlock is busy on Hyper-V framebuffer panic notifier; if so, bail-out avoiding the potential lockup scenario. Cc: Andrea Parri (Microsoft) Cc: Dexuan Cui Cc: Haiyang Zhang Cc: "K. Y. Srinivasan" Cc: Michael Kelley Cc: Stephen Hemminger Cc: Tianyu Lan Cc: Wei Liu Tested-by: Fabio A M Martins Signed-off-by: Guilherme G. Piccoli Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20220819221731.480795-10-gpiccoli@igalia.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin

Drivers: hv: vmbus: fix possible memory leak in vmbus_device_register()

2022-11-21T10:57:42+00:00

If device_register() returns error in vmbus_device_register(), the name allocated by dev_set_name() must be freed. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So fix this by calling put_device(), then the name can be freed in kobject_cleanup(). Fixes: 09d50ff8a233 ("Staging: hv: make the Hyper-V virtual bus code build") Signed-off-by: Yang Yingliang Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20221119081135.1564691-3-yangyingliang@huawei.com Signed-off-by: Wei Liu

Drivers: hv: vmbus: fix double free in the error path of vmbus_add_channel_work()

2022-11-21T10:57:41+00:00

In the error path of vmbus_device_register(), device_unregister() is called, which calls vmbus_device_release(). The latter frees the struct hv_device that was passed in to vmbus_device_register(). So remove the kfree() in vmbus_add_channel_work() to avoid a double free. Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info") Suggested-by: Michael Kelley Signed-off-by: Yang Yingliang Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20221119081135.1564691-2-yangyingliang@huawei.com Signed-off-by: Wei Liu

Drivers: hv: fix repeated words in comments

2022-10-27T10:58:14+00:00

Delete the redundant word 'of'. Signed-off-by: Jilin Yuan Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20221019125604.52999-1-yuanjilin@cdjrlc.com Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed-20221009' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2022-10-10T20:59:01+00:00

Pull hyperv updates from Wei Liu: - Remove unnecessary delay while probing for VMBus (Stanislav Kinsburskiy) - Optimize vmbus_on_event (Saurabh Sengar) - Fix a race in Hyper-V DRM driver (Saurabh Sengar) - Miscellaneous clean-up patches from various people * tag 'hyperv-next-signed-20221009' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Replace kmap() with kmap_local_page() drm/hyperv: Add ratelimit on error message hyperv: simplify and rename generate_guest_id Drivers: hv: vmbus: Split memcpy of flex-array scsi: storvsc: remove an extraneous "to" in a comment Drivers: hv: vmbus: Don't wait for the ACPI device upon initialization Drivers: hv: vmbus: Use PCI_VENDOR_ID_MICROSOFT for better discoverability Drivers: hv: vmbus: Fix kernel-doc drm/hyperv: Don't overwrite dirt_needed value set by host Drivers: hv: vmbus: Optimize vmbus_on_event