{"id":"CVE-2026-74403","state":"PUBLISHED","title":"crypto: ccp - Check for page allocation failure correctly in TIO","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Check for page allocation failure correctly in TIO\n\nSashiko notes:\n\n> if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it\n> safe to pass it directly to page_address()?\n>\n> On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might\n> compute a deterministic but invalid, non-zero virtual address. The\n> subsequent if (tio_status) check would then evaluate to true, and\n> sev_tsm_init_locked() would dereference the invalid pointer.\n\nIndeed, page_address(NULL) will return non-NULL garbage here. Fix this by\nchecking the page allocation itself for NULL, not the resulting virtual\naddress.","publishedAt":"2026-08-15T05:59:13.399Z","updatedAt":"2026-08-17T05:46:45.328Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4be423572da1f4c11f45168e3fafda870ddac9f8","status":"affected","lessThan":"17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69","versionType":"git"},{"version":"4be423572da1f4c11f45168e3fafda870ddac9f8","status":"affected","lessThan":"a8d5370eef00eca132a292b1901c9914c817e385","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]}],"references":["https://git.kernel.org/stable/c/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69","https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74403.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74403","state":"PUBLISHED","datePublished":"2026-08-15T05:59:13.399Z","dateUpdated":"2026-08-17T05:46:45.328Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.892Z"},"containers":{"cna":{"title":"crypto: ccp - Check for page allocation failure correctly in TIO","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Check for page allocation failure correctly in TIO\n\nSashiko notes:\n\n> if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it\n> safe to pass it directly to page_address()?\n>\n> On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might\n> compute a deterministic but invalid, non-zero virtual address. The\n> subsequent if (tio_status) check would then evaluate to true, and\n> sev_tsm_init_locked() would dereference the invalid pointer.\n\nIndeed, page_address(NULL) will return non-NULL garbage here. Fix this by\nchecking the page allocation itself for NULL, not the resulting virtual\naddress."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4be423572da1f4c11f45168e3fafda870ddac9f8","status":"affected","lessThan":"17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69","versionType":"git"},{"version":"4be423572da1f4c11f45168e3fafda870ddac9f8","status":"affected","lessThan":"a8d5370eef00eca132a292b1901c9914c817e385","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69"},{"url":"https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is in __sev_snp_init_locked() reached only through sev_platform_init() via KVM_SEV_INIT/KVM_SEV_INIT2 ioctls on /dev/kvm or kernel boot init; SEV-TIO platform setup has no network-facing entry point.\nAC:L - An attacker who can trigger first-time SNP init (e.g. psp_init_on_probe=0) can concurrently exhaust host memory to force __snp_alloc_firmware_pages() to return NULL and reliably reach the faulty page_address(NULL) path.\nPR:L - Reaching this code requires opening /dev/kvm and issuing KVM SNP initialization ioctls, which needs CAP_SYS_ADMIN obtainable by an unprivileged user inside a user namespace.\nUI:N - Exploitation needs only attacker-initiated KVM ioctls or boot-time SNP initialization; no action by another user or victim is required.\nS:U - Impact is confined to the host kernel during SNP-TIO initialization (oops, memory corruption); it does not cross a VM, container, or IOMMU security boundary.\nC:H - page_address(NULL) yields a non-NULL direct-map pointer, so sev_tio_init_locked() dereferences invalid memory and passes a bogus physical address to PSP firmware via SEV_CMD_TIO_STATUS, enabling kernel memory disclosure.\nI:H - The invalid pointer causes unchecked reads/writes in sev_tio_init_locked() and may direct PSP firmware to write TIO status data to an unintended physical page, enabling exploitable memory corruption.\nA:H - Dereferencing the bogus page_address(NULL) result in sev_tsm_init_locked()/sev_tio_init_locked() can trigger a kernel oops or panic, crashing the host during SNP-TIO initialization."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:46:45.328Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}