How severe is CVE-2021-47027?

CVE-2021-47027 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-47027 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47027?

CVE-2021-47027 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-47027?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2021-47027 have an EU (EUVD) identifier?

Yes. CVE-2021-47027 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33675.

When was CVE-2021-47027 published?

CVE-2021-47027 was published on 2024-02-28 and last updated on 2026-06-17.

CVE-2021-47027

CVE-2021-47027 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-33675
Affected product: Linux Linux Kernel
Published: 2024-02-28
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix kernel crash when the firmware fails to download Fix kernel crash when the firmware is missing or fails to download. [ 9.444758] kernel BUG at drivers/pci/msi.c:375! [ 9.449363] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 9.501033] pstate: a0400009 (NzCv daif +PAN -UAO) [ 9.505814] pc : free_msi_irqs+0x180/0x184 [ 9.509897] lr : free_msi_irqs+0x40/0x184 [ 9.513893] sp : ffffffc015193870 [ 9.517194] x29: ffffffc015193870 x28: 00000000f0e94fa2 [ 9.522492] x27: 0000000000000acd x26: 000000000000009a [ 9.527790] x25: ffffffc0152cee58 x24: ffffffdbb383e0d8 [ 9.533087] x23: ffffffdbb38628d0 x22: 0000000000040200 [ 9.538384] x21: ffffff8cf7de7318 x20: ffffff8cd65a2480 [ 9.543681] x19: ffffff8cf7de7000 x18: 0000000000000000 [ 9.548979] x17: ffffff8cf9ca03b4 x16: ffffffdc13ad9a34 [ 9.554277] x15: 0000000000000000 x14: 0000000000080800 [ 9.559575] x13: ffffff8cd65a2980 x12: 0000000000000000 [ 9.564873] x11: ffffff8cfa45d820 x10: ffffff8cfa45d6d0 [ 9.570171] x9 : 0000000000000040 x8 : ffffff8ccef1b780 [ 9.575469] x7 : aaaaaaaaaaaaaaaa x6 : 0000000000000000 [ 9.580766] x5 : ffffffdc13824900 x4 : ffffff8ccefe0000 [ 9.586063] x3 : 0000000000000000 x2 : 0000000000000000 [ 9.591362] x1 : 0000000000000125 x0 : ffffff8ccefe0000 [ 9.596660] Call trace: [ 9.599095] free_msi_irqs+0x180/0x184 [ 9.602831] pci_disable_msi+0x100/0x130 [ 9.606740] pci_free_irq_vectors+0x24/0x30 [ 9.610915] mt7921_pci_probe+0xbc/0x250 [mt7921e] [ 9.615693] pci_device_probe+0xd4/0x14c [ 9.619604] really_probe+0x134/0x2ec [ 9.623252] driver_probe_device+0x64/0xfc [ 9.627335] device_driver_attach+0x4c/0x6c [ 9.631506] __driver_attach+0xac/0xc0 [ 9.635243] bus_for_each_dev+0x8c/0xd4 [ 9.639066] driver_attach+0x2c/0x38 [ 9.642628] bus_add_driver+0xfc/0x1d0 [ 9.646365] driver_register+0x64/0xf8 [ 9.650101] __pci_register_driver+0x6c/0x7c [ 9.654360] init_module+0x28/0xfdc [mt7921e] [ 9.658704] do_one_initcall+0x13c/0x2d0 [ 9.662615] do_init_module+0x58/0x1e8 [ 9.666351] load_module+0xd80/0xeb4 [ 9.669912] __arm64_sys_finit_module+0xa8/0xe0 [ 9.674430] el0_svc_common+0xa4/0x16c [ 9.678168] el0_svc_compat_handler+0x2c/0x40 [ 9.682511] el0_svc_compat+0x8/0x10 [ 9.686076] Code: a94257f6 f9400bf7 a8c47bfd d65f03c0 (d4210000) [ 9.692155] ---[ end trace 7621f966afbf0a29 ]--- [ 9.697385] Kernel panic - not syncing: Fatal exception [ 9.702599] SMP: stopping secondary CPUs [ 9.706549] Kernel Offset: 0x1c03600000 from 0xffffffc010000000 [ 9.712456] PHYS_OFFSET: 0xfffffff440000000 [ 9.716625] CPU features: 0x080026,2a80aa18 [ 9.720795] Memory Limit: none

Frequently asked questions

What is CVE-2021-47027?: In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix kernel crash when the firmware fails to download Fix kernel crash when the firmware is missing or fails to download. [ 9.444758] kernel BUG at drivers/pci/msi.c:375! [ 9.449363] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 9.501033] pstate: a0400009 (NzCv daif +PAN -UAO) [ 9.505814] pc : free_msi_irqs+0x180/0x184 [ 9.509897] lr : free_msi_irqs+0x40/0x184 [ 9.513893] sp : ffffffc015193870 [ 9.517194] x29: ffffffc015193870 x28: 00000000f0e94fa2 [ 9.522492] x27: 0000000000000acd x26: 000000000000009a [ 9.527790] x25: ffffffc0152cee58 x24: ffffffdbb383e0d8 [ 9.533087] x23: ffffffdbb38628d0 x22: 0000000000040200 [ 9.538384] x21: ffffff8cf7de7318 x20: ffffff8cd65a2480 [ 9.543681] x19: ffffff8cf7de7000 x18: 0000000000000000 [ 9.548979] x17: ffffff8cf9ca03b4 x16: ffffffdc13ad9a34 [ 9.554277] x15: 0000000000000000 x14: 0000000000080800 [ 9.559575] x13: ffffff8cd65a2980 x12: 0000000000000000 [ 9.564873] x11: ffffff8cfa45d820 x10: ffffff8cfa45d6d0 [ 9.570171] x9 : 0000000000000040 x8 : ffffff8ccef1b780 [ 9.575469] x7 : aaaaaaaaaaaaaaaa x6 : 0000000000000000 [ 9.580766] x5 : ffffffdc13824900 x4 : ffffff8ccefe0000 [ 9.586063] x3 : 0000000000000000 x2 : 0000000000000000 [ 9.591362] x1 : 0000000000000125 x0 : ffffff8ccefe0000 [ 9.596660] Call trace: [ 9.599095] free_msi_irqs+0x180/0x184 [ 9.602831] pci_disable_msi+0x100/0x130 [ 9.606740] pci_free_irq_vectors+0x24/0x30 [ 9.610915] mt7921_pci_probe+0xbc/0x250 [mt7921e] [ 9.615693] pci_device_probe+0xd4/0x14c [ 9.619604] really_probe+0x134/0x2ec [ 9.623252] driver_probe_device+0x64/0xfc [ 9.627335] device_driver_attach+0x4c/0x6c [ 9.631506] __driver_attach+0xac/0xc0 [ 9.635243] bus_for_each_dev+0x8c/0xd4 [ 9.639066] driver_attach+0x2c/0x38 [ 9.642628] bus_add_driver+0xfc/0x1d0 [ 9.646365] driver_register+0x64/0xf8 [ 9.650101] __pci_register_driver+0x6c/0x7c [ 9.654360] init_module+0x28/0xfdc [mt7921e] [ 9.658704] do_one_initcall+0x13c/0x2d0 [ 9.662615] do_init_module+0x58/0x1e8 [ 9.666351] load_module+0xd80/0xeb4 [ 9.669912] __arm64_sys_finit_module+0xa8/0xe0 [ 9.674430] el0_svc_common+0xa4/0x16c [ 9.678168] el0_svc_compat_handler+0x2c/0x40 [ 9.682511] el0_svc_compat+0x8/0x10 [ 9.686076] Code: a94257f6 f9400bf7 a8c47bfd d65f03c0 (d4210000) [ 9.692155] ---[ end trace 7621f966afbf0a29 ]--- [ 9.697385] Kernel panic - not syncing: Fatal exception [ 9.702599] SMP: stopping secondary CPUs [ 9.706549] Kernel Offset: 0x1c03600000 from 0xffffffc010000000 [ 9.712456] PHYS_OFFSET: 0xfffffff440000000 [ 9.716625] CPU features: 0x080026,2a80aa18 [ 9.720795] Memory Limit: none
How severe is CVE-2021-47027?: CVE-2021-47027 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47027 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47027?: CVE-2021-47027 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47027?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47027 have an EU (EUVD) identifier?: Yes. CVE-2021-47027 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33675.
When was CVE-2021-47027 published?: CVE-2021-47027 was published on 2024-02-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

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