# CVE-2026-43475: scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT

> A scheduling while atomic bug in the storvsc driver causes system lock-ups on PREEMPT_RT kernels, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 May 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-43475, DEBIAN-CVE-2026-43475, GHSA-5rpf-7pmv-82cj, ROOT-OS-DEBIAN-11-CVE-2026-43475, ROOT-OS-UBUNTU-2204-CVE-2026-43475, ROOT-OS-UBUNTU-2404-CVE-2026-43475, UBUNTU-CVE-2026-43475

## What is CVE-2026-43475?

CVE-2026-43475 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT

This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:

[  415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[  415.140822] INFO: lockdep is turned off.
[  415.140823] Modules linked in: intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery pmt_class intel_pmc_ssram_telemetry intel_vsec ghash_clmulni_intel aesni_intel rapl binfmt_misc nls_ascii nls_cp437 vfat fat snd_pcm hyperv_drm snd_timer drm_client_lib drm_shmem_helper snd sg soundcore drm_kms_helper pcspkr hv_balloon hv_utils evdev joydev drm configfs efi_pstore nfnetlink vsock_loopback vmw_vsock_virtio_transport_common hv_sock vmw_vsock_vmci_transport vsock vmw_vmci efivarfs autofs4 ext4 crc16 mbcache jbd2 sr_mod sd_mod cdrom hv_storvsc serio_raw hid_generic scsi_transport_fc hid_hyperv scsi_mod hid hv_netvsc hyperv_keyboard scsi_common
[  415.140846] Preemption disabled at:
[  415.140847] [<ffffffffc0656171>] storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc]
[  415.140854] CPU: 8 UID: 0 PID: 1048 Comm: stress-ng-iomix Not tainted 6.19.0-rc7 #30 PREEMPT_{RT,(full)}
[  415.140856] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/04/2024
[  415.140857] Call Trace:
[  415.140861]  <TASK>
[  415.140861]  ? storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc]
[  415.140863]  dump_stack_lvl+0x91/0xb0
[  415.140870]  __schedule_bug+0x9c/0xc0
[  415.140875]  __schedule+0xdf6/0x1300
[  415.140877]  ? rtlock_slowlock_locked+0x56c/0x1980
[  415.140879]  ? rcu_is_watching+0x12/0x60
[  415.140883]  schedule_rtlock+0x21/0x40
[  415.140885]  rtlock_slowlock_locked+0x502/0x1980
[  415.140891]  rt_spin_lock+0x89/0x1e0
[  415.140893]  hv_ringbuffer_write+0x87/0x2a0
[  415.140899]  vmbus_sendpacket_mpb_desc+0xb6/0xe0
[  415.140900]  ? rcu_is_watching+0x12/0x60
[  415.140902]  storvsc_queuecommand+0x669/0xbe0 [hv_storvsc]
[  415.140904]  ? HARDIRQ_verbose+0x10/0x10
[  415.140908]  ? __rq_qos_issue+0x28/0x40
[  415.140911]  scsi_queue_rq+0x760/0xd80 [scsi_mod]
[  415.140926]  __blk_mq_issue_directly+0x4a/0xc0
[  415.140928]  blk_mq_issue_direct+0x87/0x2b0
[  415.140931]  blk_mq_dispatch_queue_requests+0x120/0x440
[  415.140933]  blk_mq_flush_plug_list+0x7a/0x1a0
[  415.140935]  __blk_flush_plug+0xf4/0x150
[  415.140940]  __submit_bio+0x2b2/0x5c0
[  415.140944]  ? submit_bio_noacct_nocheck+0x272/0x360
[  415.140946]  submit_bio_noacct_nocheck+0x272/0x360
[  415.140951]  ext4_read_bh_lock+0x3e/0x60 [ext4]
[  415.140995]  ext4_block_write_begin+0x396/0x650 [ext4]
[  415.141018]  ? __pfx_ext4_da_get_block_prep+0x10/0x10 [ext4]
[  415.141038]  ext4_da_write_begin+0x1c4/0x350 [ext4]
[  415.141060]  generic_perform_write+0x14e/0x2c0
[  415.141065]  ext4_buffered_write_iter+0x6b/0x120 [ext4]
[  415.141083]  vfs_write+0x2ca/0x570
[  415.141087]  ksys_write+0x76/0xf0
[  415.141089]  do_syscall_64+0x99/0x1490
[  415.141093]  ? rcu_is_watching+0x12/0x60
[  415.141095]  ? finish_task_switch.isra.0+0xdf/0x3d0
[  415.141097]  ? rcu_is_watching+0x12/0x60
[  415.141098]  ? lock_release+0x1f0/0x2a0
[  415.141100]  ? rcu_is_watching+0x12/0x60
[  415.141101]  ? finish_task_switch.isra.0+0xe4/0x3d0
[  415.141103]  ? rcu_is_watching+0x12/0x60
[  415.141104]  ? __schedule+0xb34/0x1300
[  415.141106]  ? hrtimer_try_to_cancel+0x1d/0x170
[  415.141109]  ? do_nanosleep+0x8b/0x160
[  415.141111]  ? hrtimer_nanosleep+0x89/0x100
[  415.141114]  ? __pfx_hrtimer_wakeup+0x10/0x10
[  415.141116]  ? xfd_validate_state+0x26/0x90
[  415.141118]  ? rcu_is_watching+0x12/0x60
[  415.141120]  ? do_syscall_64+0x1e0/0x1490
[  415.141121]  ? do_syscall_64+0x1e0/0x1490
[  415.141123]  ? rcu_is_watching+0x12/0x60
[  415.141124]  ? do_syscall_64+0x1e0/0x1490
[  415.141125]  ? do_syscall_64+0x1e0/0x1490
[  415.141127]  ? irqentry_exit+0x140/0
---truncated---

## Which versions are affected by CVE-2026-43475?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43475?

Apply the vendor's patch.

## Is CVE-2026-43475 being exploited?

There is no known exploitation of CVE-2026-43475 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43475 and fix it if it is affected.

What it is: CVE-2026-43475 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-43475 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43475/ (Markdown: https://insights.sbomify.com/CVE-2026-43475/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43475
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43475
- OSV: https://osv.dev/vulnerability/CVE-2026-43475

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43475/
Summaries are generated and may contain mistakes; the official description above is the record.
