Linux kernel crypto/ccp SEV PDH export out-of-bounds read information leak
CVE-2026-31698 is a vulnerability in the Linux kernel crypto/ccp SEV driver, specifically in the PDH certificate export path handled by sev_ioctl_do_pdh_export() in drivers/crypto/ccp/sev-dev.c. When retrieving the PDH certificate, the kernel could attempt to copy PDH certificate blobs to userspace even if the underlying PSP firmware command failed. In the failure case where the user-supplied buffer length was too small, firmware could report a larger required size than the kernel originally allocated. The kernel then used that firmware-reported length during copy_to_user(), causing a slab out-of-bounds read from the kernel-allocated buffer. KASAN reports show the issue manifesting as a slab-out-of-bounds read in instrument_copy_to_user/_copy_to_user on the sev_ioctl_do_pdh_export() path. The upstream fix prevents copying PDH certificate data to userspace when the PSP command fails and adds a warning for inconsistent success/error reporting from the firmware command path.
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Impact
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Mitigation
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Exploits
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Recent activity
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Linux kernel vulnerability in crypto ccp PDH certificate copy handling after PSP command failure.
A Linux kernel vulnerability in the crypto CCP component involving copying a PDH certificate to userspace after a failed PSP command.
A Linux kernel information disclosure vulnerability in the crypto/ccp SEV PDH certificate export path, where a failed PSP firmware command can still lead to copying more data than allocated to userspace, causing a slab out-of-bounds read and kernel memory leak.
Linux kernel vulnerability in crypto ccp where failed PSP commands could still trigger copying PDH certificate data to userspace.
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Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
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Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.