{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31698", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.131Z", "datePublished": "2026-05-01T13:55:58.854Z", "dateUpdated": "2026-08-05T12:24:35.659Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:35.659Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed\n\nWhen retrieving the PDH cert, don't attempt to copy the blobs to userspace\nif the firmware command failed. If the failure was due to an invalid\nlength, i.e. the userspace buffer+length was too small, copying the number\nof bytes _firmware_ requires will overflow the kernel-allocated buffer and\nleak data to userspace.\n\n BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]\n BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]\n BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26\n Read of size 2084 at addr ffff8885c4ab8aa0 by task syz.0.186/21033\n\n CPU: 51 UID: 0 PID: 21033 Comm: syz.0.186 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY\n Tainted: [U]=USER, [O]=OOT_MODULE\n Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.84.12-0 11/17/2025\n Call Trace:\n \n dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120\n print_address_description ../mm/kasan/report.c:378 [inline]\n print_report+0xbc/0x260 ../mm/kasan/report.c:482\n kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595\n check_region_inline ../mm/kasan/generic.c:-1 [inline]\n kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200\n instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]\n _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]\n _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26\n copy_to_user ../include/linux/uaccess.h:236 [inline]\n sev_ioctl_do_pdh_export+0x3d3/0x7c0 ../drivers/crypto/ccp/sev-dev.c:2347\n sev_ioctl+0x2a2/0x490 ../drivers/crypto/ccp/sev-dev.c:2568\n vfs_ioctl ../fs/ioctl.c:51 [inline]\n __do_sys_ioctl ../fs/ioctl.c:597 [inline]\n __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583\n do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n \n\nWARN if the driver says the command succeeded, but the firmware error code\nsays otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any\nfirwmware error." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached through the local `/dev/sev` misc device via the `SEV_ISSUE_CMD` ioctl and `SEV_PDH_CERT_EXPORT` command, not by network or adjacent packets.\nAC:L - An attacker who can access `/dev/sev` can supply undersized nonzero certificate buffers and reliably make firmware return the required larger lengths; no race or hard-to-influence condition is required.\nPR:L - The kernel path has no capability check, and although `/dev/sev` is often root-restricted by default, SEV-capable hosts commonly delegate access to non-root virtualization users or groups; using the higher-severity reasonable case makes this low privileges.\nUI:N - No victim action is required after the attacker has local access to the device; the ioctl directly triggers the vulnerable path.\nS:U - The bug leaks or crashes kernel memory in the same host kernel security authority; it is not a VM escape or other cross-scope boundary violation by itself.\nC:H - The failed firmware command overwrites the returned lengths with larger required sizes, and the vulnerable code copies that many bytes from smaller kernel heap buffers to userspace, producing an out-of-bounds kernel memory disclosure.\nI:N - The bug is an out-of-bounds read during `copy_to_user`, with no direct write, memory corruption, or control-flow modification primitive.\nA:H - The same out-of-bounds usercopy is reported as a KASAN slab-out-of-bounds read and can also trip hardened usercopy BUG/oops paths on hardened kernels, making a kernel crash a defensible impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/crypto/ccp/sev-dev.c" ], "versions": [ { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "af67d35da744b6b678c7a0296d9c679658779829", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "854d7846e1d29f32f1bbeb2e869e794df12067f6", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "25d9b3446001185484209cf57951f3368462b631", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "b5c14bd4da1f376f385722fe1da993f1edab6472", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "051e51aa55fd4cdc3e8283cf4476aeeb5f563274", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "50808c13452dae43a2c90b1bbbf9daa16501ce70", "status": "affected", "versionType": "git" }, { "version": "76a2b524a4b1d6dc0f2421f9854a01d55d5e5436", "lessThan": "e76239fed3cffd6d304d8ca3ce23984fd24f57d3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/crypto/ccp/sev-dev.c" ], "versions": [ { "version": "4.16", "status": "affected" }, { "version": "0", "lessThan": "4.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.136", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.84", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.25", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.2", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.6.136" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.12.84" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.18.25" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.0.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/af67d35da744b6b678c7a0296d9c679658779829" }, { "url": "https://git.kernel.org/stable/c/854d7846e1d29f32f1bbeb2e869e794df12067f6" }, { "url": "https://git.kernel.org/stable/c/25d9b3446001185484209cf57951f3368462b631" }, { "url": "https://git.kernel.org/stable/c/b5c14bd4da1f376f385722fe1da993f1edab6472" }, { "url": "https://git.kernel.org/stable/c/78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf" }, { "url": "https://git.kernel.org/stable/c/051e51aa55fd4cdc3e8283cf4476aeeb5f563274" }, { "url": "https://git.kernel.org/stable/c/50808c13452dae43a2c90b1bbbf9daa16501ce70" }, { "url": "https://git.kernel.org/stable/c/e76239fed3cffd6d304d8ca3ce23984fd24f57d3" } ], "title": "crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed", "x_generator": { "engine": "bippy-1.2.0" } } } }