{"id":"CVE-2025-40051","state":"PUBLISHED","title":"vhost: vringh: Modify the return value check","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost: vringh: Modify the return value check\n\nThe return value of copy_from_iter and copy_to_iter can't be negative,\ncheck whether the copied lengths are equal.","publishedAt":"2025-10-28T11:48:27.279Z","updatedAt":"2026-10-15T22:02:36.974Z","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":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"db042925a5ab7a550b710addeadbf6f72e3a8a4b","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"78dc7362662fedaa1928fb8e4f27401c8322905d","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"baa37b1c7e29546f79c39bef0d18c4edc9f39bb1","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"cfa0654402c06d086201a9ff167eb95da5844fc3","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"82a8d0fda55b35361ee7f35b54fa2b66d7847d2b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vringh.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.156","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.112","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.53","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.3","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vringh.c"]}],"references":["https://git.kernel.org/stable/c/db042925a5ab7a550b710addeadbf6f72e3a8a4b","https://git.kernel.org/stable/c/78dc7362662fedaa1928fb8e4f27401c8322905d","https://git.kernel.org/stable/c/baa37b1c7e29546f79c39bef0d18c4edc9f39bb1","https://git.kernel.org/stable/c/cfa0654402c06d086201a9ff167eb95da5844fc3","https://git.kernel.org/stable/c/82a8d0fda55b35361ee7f35b54fa2b66d7847d2b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40051.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40051","state":"PUBLISHED","datePublished":"2025-10-28T11:48:27.279Z","dateUpdated":"2026-10-15T22:02:36.974Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.157Z"},"containers":{"cna":{"title":"vhost: vringh: Modify the return value check","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost: vringh: Modify the return value check\n\nThe return value of copy_from_iter and copy_to_iter can't be negative,\ncheck whether the copied lengths are equal."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"db042925a5ab7a550b710addeadbf6f72e3a8a4b","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"78dc7362662fedaa1928fb8e4f27401c8322905d","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"baa37b1c7e29546f79c39bef0d18c4edc9f39bb1","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"cfa0654402c06d086201a9ff167eb95da5844fc3","versionType":"git"},{"version":"309bba39c945ac8ab8083ac05cd6cfe5822968e0","status":"affected","lessThan":"82a8d0fda55b35361ee7f35b54fa2b66d7847d2b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vringh.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.156","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.112","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.53","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.3","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vringh.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/db042925a5ab7a550b710addeadbf6f72e3a8a4b"},{"url":"https://git.kernel.org/stable/c/78dc7362662fedaa1928fb8e4f27401c8322905d"},{"url":"https://git.kernel.org/stable/c/baa37b1c7e29546f79c39bef0d18c4edc9f39bb1"},{"url":"https://git.kernel.org/stable/c/cfa0654402c06d086201a9ff167eb95da5844fc3"},{"url":"https://git.kernel.org/stable/c/82a8d0fda55b35361ee7f35b54fa2b66d7847d2b"}],"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 vulnerable vringh IOTLB copy path is driven entirely through local ioctls on the `/dev/vhost-vdpa-N` character device (VHOST_IOTLB_UPDATE, vring setup, kick), with no network-facing consumer. A malicious guest cannot trigger it because it cannot unmap the host-side VA backing, so the attacker must be a local process.\nAC:L - The attacker deterministically forces the short copy by registering an IOTLB mapping over a shared file mapping and then truncating/unmapping it, so `copy_from_user` faults at a chosen offset every time — no race or unpredictable state is involved. The stale-stack values feeding `hdr.sector` and `struct vring_desc` are groomable with ordinary syscalls.\nPR:L - `vhost_vdpa_open()` and the vhost-vdpa ioctl handlers contain no `capable()`/`CAP_*` checks, so any user holding the device node can drive the full path, and in standard virtualization deployments that node is granted to an unprivileged VMM process. Only device *creation* needs admin, which is the normal host configuration, not an attacker step.\nUI:N - The attacker performs every step itself — map, truncate, kick the virtqueue — within its own process. No victim action or interaction is required.\nS:U - The corruption and disclosure occur in the host kernel that already governs the attacking process; this is standard local kernel compromise. No IOMMU, VM, or sandbox authority boundary is crossed by the bug itself.\nC:H - A silently-swallowed short pull causes `vdpasim_net_work()` to push a full PAGE_SIZE of the non-zeroed `kvmalloc` buffer `net->buffer` into the attacker's RX ring, directly disclosing stale kernel heap. Additionally the uninitialized `hdr.sector` drives `vringh_iov_push_iotlb(..., blk->buffer + offset, ...)` past the wrapped `VDPASIM_BLK_CAPACITY - start_sector` guard, giving an out-of-bounds kernel heap read echoed back to the attacker.\nI:H - In `vdpasim_blk_handle_req()` the uninitialized stack `hdr.sector` becomes the destination offset for `vringh_iov_pull_iotlb(..., blk->buffer + (sector << SECTOR_SHIFT), to_pull)`, an out-of-bounds kernel heap write of attacker-supplied data at a groomable offset. `__vringh_iov()` likewise builds iov entries whose `iov_base`/`iov_len` come from uninitialized kernel stack, giving further attacker-influenced memory corruption.\nA:H - Descriptors and request headers fabricated from uninitialized kernel stack yield bogus IOVAs and lengths up to 4 GB, and the resulting out-of-bounds heap accesses and invalid `pfn_to_page()`/page translations cause kernel oops or panic. The condition is repeatable at will from a single unprivileged process."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:07:22.761Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.156"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.17.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-40051","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:56:30.680415Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T22:02:36.974Z"}}]}}}