CVE-2026-43475: scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT
In the Linux kernel, the following vulnerability has been resolved:
scsi: storvsc: Fix scheduling while atomic on PREEMPTRT
This resolves the follow splat and lock-up when running with PREEMPTRT 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: intelraplmsr intelraplcommon inteluncorefrequencycommon intelpmccore pmttelemetry pmtdiscovery pmtclass intelpmcssramtelemetry intelvsec ghashclmulniintel aesniintel rapl binfmtmisc nlsascii nlscp437 vfat fat sndpcm hypervdrm sndtimer drmclientlib drmshmemhelper snd sg soundcore drmkmshelper pcspkr hvballoon hvutils evdev joydev drm configfs efipstore nfnetlink vsockloopback vmwvsockvirtiotransportcommon hvsock vmwvsockvmcitransport vsock vmwvmci efivarfs autofs4 ext4 crc16 mbcache jbd2 srmod sdmod cdrom hvstorvsc serioraw hidgeneric scsitransportfc hidhyperv scsimod hid hvnetvsc hypervkeyboard scsicommon [ 415.140846] Preemption disabled at: [ 415.140847] [<ffffffffc0656171>] storvscqueuecommand+0x2e1/0xbe0 [hvstorvsc] [ 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] ? storvscqueuecommand+0x2e1/0xbe0 [hvstorvsc] [ 415.140863] dumpstacklvl+0x91/0xb0 [ 415.140870] schedulebug+0x9c/0xc0 [ 415.140875] schedule+0xdf6/0x1300 [ 415.140877] ? rtlockslowlocklocked+0x56c/0x1980 [ 415.140879] ? rcuiswatching+0x12/0x60 [ 415.140883] schedulertlock+0x21/0x40 [ 415.140885] rtlockslowlocklocked+0x502/0x1980 [ 415.140891] rtspinlock+0x89/0x1e0 [ 415.140893] hvringbufferwrite+0x87/0x2a0 [ 415.140899] vmbussendpacketmpbdesc+0xb6/0xe0 [ 415.140900] ? rcuiswatching+0x12/0x60 [ 415.140902] storvscqueuecommand+0x669/0xbe0 [hvstorvsc] [ 415.140904] ? HARDIRQverbose+0x10/0x10 [ 415.140908] ? rqqosissue+0x28/0x40 [ 415.140911] scsiqueuerq+0x760/0xd80 [scsimod] [ 415.140926] blkmqissuedirectly+0x4a/0xc0 [ 415.140928] blkmqissuedirect+0x87/0x2b0 [ 415.140931] blkmqdispatchqueuerequests+0x120/0x440 [ 415.140933] blkmqflushpluglist+0x7a/0x1a0 [ 415.140935] blkflushplug+0xf4/0x150 [ 415.140940] submitbio+0x2b2/0x5c0 [ 415.140944] ? submitbionoacctnocheck+0x272/0x360 [ 415.140946] submitbionoacctnocheck+0x272/0x360 [ 415.140951] ext4readbhlock+0x3e/0x60 [ext4] [ 415.140995] ext4blockwritebegin+0x396/0x650 [ext4] [ 415.141018] ? pfxext4dagetblockprep+0x10/0x10 [ext4] [ 415.141038] ext4dawritebegin+0x1c4/0x350 [ext4] [ 415.141060] genericperformwrite+0x14e/0x2c0 [ 415.141065] ext4bufferedwriteiter+0x6b/0x120 [ext4] [ 415.141083] vfswrite+0x2ca/0x570 [ 415.141087] ksyswrite+0x76/0xf0 [ 415.141089] dosyscall64+0x99/0x1490 [ 415.141093] ? rcuiswatching+0x12/0x60 [ 415.141095] ? finishtaskswitch.isra.0+0xdf/0x3d0 [ 415.141097] ? rcuiswatching+0x12/0x60 [ 415.141098] ? lockrelease+0x1f0/0x2a0 [ 415.141100] ? rcuiswatching+0x12/0x60 [ 415.141101] ? finishtaskswitch.isra.0+0xe4/0x3d0 [ 415.141103] ? rcuiswatching+0x12/0x60 [ 415.141104] ? schedule+0xb34/0x1300 [ 415.141106] ? hrtimertrytocancel+0x1d/0x170 [ 415.141109] ? donanosleep+0x8b/0x160 [ 415.141111] ? hrtimernanosleep+0x89/0x100 [ 415.141114] ? pfxhrtimerwakeup+0x10/0x10 [ 415.141116] ? xfdvalidatestate+0x26/0x90 [ 415.141118] ? rcuiswatching+0x12/0x60 [ 415.141120] ? dosyscall64+0x1e0/0x1490 [ 415.141121] ? dosyscall64+0x1e0/0x1490 [ 415.141123] ? rcuiswatching+0x12/0x60 [ 415.141124] ? dosyscall64+0x1e0/0x1490 [ 415.141125] ? dosyscall64+0x1e0/0x1490 [ 415.141127] ? irqentryexit+0x140/0 ---truncated---
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43475?
CVE-2026-43475 has a high severity rating due to its potential to cause system lock-ups when running with PREEMPT_RT enabled.
How do I fix CVE-2026-43475?
To fix CVE-2026-43475, update to the latest version of the Linux kernel that includes the patch for the storvsc driver.
What systems are affected by CVE-2026-43475?
CVE-2026-43475 affects systems running the Linux kernel with the storvsc driver on Hyper-V.
What are the potential consequences of CVE-2026-43475?
The potential consequences of CVE-2026-43475 include system instability and lock-ups, particularly when using real-time preemption.
When was CVE-2026-43475 disclosed?
CVE-2026-43475 was disclosed in 2026 following the identification of the bug related to scheduling while atomic.