CVE-2025-39936

CVE-2025-39936 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. The underlying weakness is classified as CWE-476.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Always pass in an error pointer to __sev_platform_shutdown_locked() When 9770b428b1a2 ("crypto: ccp - Move dev_info/err messages for SEV/SNP init and shutdown") moved the error messages dumping so that they don't need to be issued by the callers, it missed the case where __sev_firmware_shutdown() calls __sev_platform_shutdown_locked() with a NULL argument which leads to a NULL ptr deref on the shutdown path, during suspend to disk: #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 983 Comm: hib.sh Not tainted 6.17.0-rc4+ #1 PREEMPT(voluntary) Hardware name: Supermicro Super Server/H12SSL-i, BIOS 2.5 09/08/2022 RIP: 0010:__sev_platform_shutdown_locked.cold+0x0/0x21 [ccp] That rIP is: 00000000000006fd <__sev_platform_shutdown_locked.cold>: 6fd: 8b 13 mov (%rbx),%edx 6ff: 48 8b 7d 00 mov 0x0(%rbp),%rdi 703: 89 c1 mov %eax,%ecx Code: 74 05 31 ff 41 89 3f 49 8b 3e 89 ea 48 c7 c6 a0 8e 54 a0 41 bf 92 ff ff ff e8 e5 2e 09 e1 c6 05 2a d4 38 00 01 e9 26 af ff ff <8b> 13 48 8b 7d 00 89 c1 48 c7 c6 18 90 54 a0 89 44 24 04 e8 c1 2e RSP: 0018:ffffc90005467d00 EFLAGS: 00010282 RAX: 00000000ffffff92 RBX: 0000000000000000 RCX: 0000000000000000 ^^^^^^^^^^^^^^^^ and %rbx is nice and clean. Call Trace: <TASK> __sev_firmware_shutdown.isra.0 sev_dev_destroy psp_dev_destroy sp_destroy pci_device_shutdown device_shutdown kernel_power_off hibernate.cold state_store kernfs_fop_write_iter vfs_write ksys_write do_syscall_64 entry_SYSCALL_64_after_hwframe Pass in a pointer to the function-local error var in the caller. With that addressed, suspending the ccp shows the error properly at least: ccp 0000:47:00.1: sev command 0x2 timed out, disabling PSP ccp 0000:47:00.1: SEV: failed to SHUTDOWN error 0x0, rc -110 SEV-SNP: Leaking PFN range 0x146800-0x146a00 SEV-SNP: PFN 0x146800 unassigned, dumping non-zero entries in 2M PFN region: [0x146800 - 0x146a00] ... ccp 0000:47:00.1: SEV-SNP firmware shutdown failed, rc -16, error 0x0 ACPI: PM: Preparing to enter system sleep state S5 kvm: exiting hardware virtualization reboot: Power down Btw, this driver is crying to be cleaned up to pass in a proper I/O struct which can be used to store information between the different functions, otherwise stuff like that will happen in the future again.

Frequently asked questions

What is CVE-2025-39936?
In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Always pass in an error pointer to __sev_platform_shutdown_locked() When 9770b428b1a2 ("crypto: ccp - Move dev_info/err messages for SEV/SNP init and shutdown") moved the error messages dumping so that they don't need to be issued by the callers, it missed the case where __sev_firmware_shutdown() calls __sev_platform_shutdown_locked() with a NULL argument which leads to a NULL ptr deref on the shutdown path, during suspend to disk: #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 983 Comm: hib.sh Not tainted 6.17.0-rc4+ #1 PREEMPT(voluntary) Hardware name: Supermicro Super Server/H12SSL-i, BIOS 2.5 09/08/2022 RIP: 0010:__sev_platform_shutdown_locked.cold+0x0/0x21 [ccp] That rIP is: 00000000000006fd <__sev_platform_shutdown_locked.cold>: 6fd: 8b 13 mov (%rbx),%edx 6ff: 48 8b 7d 00 mov 0x0(%rbp),%rdi 703: 89 c1 mov %eax,%ecx Code: 74 05 31 ff 41 89 3f 49 8b 3e 89 ea 48 c7 c6 a0 8e 54 a0 41 bf 92 ff ff ff e8 e5 2e 09 e1 c6 05 2a d4 38 00 01 e9 26 af ff ff <8b> 13 48 8b 7d 00 89 c1 48 c7 c6 18 90 54 a0 89 44 24 04 e8 c1 2e RSP: 0018:ffffc90005467d00 EFLAGS: 00010282 RAX: 00000000ffffff92 RBX: 0000000000000000 RCX: 0000000000000000 ^^^^^^^^^^^^^^^^ and %rbx is nice and clean. Call Trace: <TASK> __sev_firmware_shutdown.isra.0 sev_dev_destroy psp_dev_destroy sp_destroy pci_device_shutdown device_shutdown kernel_power_off hibernate.cold state_store kernfs_fop_write_iter vfs_write ksys_write do_syscall_64 entry_SYSCALL_64_after_hwframe Pass in a pointer to the function-local error var in the caller. With that addressed, suspending the ccp shows the error properly at least: ccp 0000:47:00.1: sev command 0x2 timed out, disabling PSP ccp 0000:47:00.1: SEV: failed to SHUTDOWN error 0x0, rc -110 SEV-SNP: Leaking PFN range 0x146800-0x146a00 SEV-SNP: PFN 0x146800 unassigned, dumping non-zero entries in 2M PFN region: [0x146800 - 0x146a00] ... ccp 0000:47:00.1: SEV-SNP firmware shutdown failed, rc -16, error 0x0 ACPI: PM: Preparing to enter system sleep state S5 kvm: exiting hardware virtualization reboot: Power down Btw, this driver is crying to be cleaned up to pass in a proper I/O struct which can be used to store information between the different functions, otherwise stuff like that will happen in the future again.
How severe is CVE-2025-39936?
CVE-2025-39936 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-2025-39936 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39936?
CVE-2025-39936 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39936?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-39936 have an EU (EUVD) identifier?
Yes. CVE-2025-39936 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-32401.
When was CVE-2025-39936 published?
CVE-2025-39936 was published on 2025-10-04 and last updated on 2026-06-17.

References

Affected products (7)

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