{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72310", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.918Z", "datePublished": "2026-08-15T05:55:26.539Z", "dateUpdated": "2026-08-17T05:42:38.636Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:42:38.636Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix overflow in passthrough ioctl bounds check\n\nsmb2_ioctl_query_info() validates the PASSTHRU_FSCTL response payload\nbefore copying it to userspace.\n\nThe payload offset and length both come from 32-bit fields. The bounds\ncheck currently adds OutputOffset and qi.input_buffer_length directly, so\nthe addition can wrap in 32-bit arithmetic before the result is compared\nagainst the response buffer length.\n\nA malicious server can use a large OutputOffset and a small OutputCount\nto make the wrapped sum pass the bounds check. The later copy_to_user()\nthen reads from io_rsp + OutputOffset, outside the response buffer.\n\nUse size_add() for the offset plus length check so overflow is treated as\nout of bounds." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 8.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - Exploitation requires processing a crafted SMB2 IOCTL response from a malicious SMB/CIFS server over TCP; the bug is in client-side parsing of attacker-controlled network protocol fields, not in a purely local code path.\nAC:L - A malicious server can reliably supply OutputOffset and OutputCount values that wrap the 32-bit bounds check and pass validation, deterministically triggering the out-of-bounds copy_to_user() without races or special victim state.\nPR:L - The PASSTHRU_FSCTL ioctl path requires CAP_SYS_ADMIN, which an unprivileged local user can obtain inside a user namespace and use to mount CIFS and issue CIFS_QUERY_INFO against an attacker-controlled server.\nUI:N - In the highest-impact scenario the attacker controls the full chain (user-namespace mount plus ioctl) and needs no separate victim action beyond their own exploitation steps.\nS:U - Impact is disclosure of kernel heap memory to the calling userspace process within the same kernel security authority; it does not cross VM, IOMMU, or sandbox boundaries.\nC:H - The integer overflow bypasses bounds checking so copy_to_user() reads qi.input_buffer_length bytes from io_rsp plus attacker-chosen OutputOffset outside the SMB response buffer, leaking adjacent kernel memory to userspace.\nI:N - The flaw is an out-of-bounds kernel read copied to userspace; it does not modify kernel memory, corrupt metadata, or provide a write or code-execution primitive.\nA:H - Reading far outside the allocated SMB response buffer can access unmapped kernel pages during copy_to_user(), causing a kernel fault, oops, or panic in addition to information disclosure." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/smb2ops.c" ], "versions": [ { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "175357ee0c596cb82054650dfa32fda51ad35aaa", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "dbd126539c098dba3159ce7d34b10b2daddcbd0f", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "63feb687e89a3a52a31e6e01764117cc500f1974", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "160045fc943f6c46b227644261252c8a22b8a87a", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "b30771b69eafae750afb7385fbcc3d77ed3f3670", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "1627e7d5c9b09721a141d07cedb178882f1ded67", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "1a638c55f2db6cb2296e5e3138015dd8fd9d4aa9", "status": "affected", "versionType": "git" }, { "version": "2b1116bbe898aefdf584838448c6869f69851e0f", "lessThan": "a4f27ad055392fa164f5649e89a3637b033c5fcc", "status": "affected", "versionType": "git" }, { "version": "2005c32ec99ee2490e8131b3953f3f212009ffea", "status": "affected", "versionType": "git" }, { "version": "5.4.69", "lessThan": "5.5", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/smb2ops.c" ], "versions": [ { "version": "5.5", "status": "affected" }, { "version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "5.5", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.69" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/175357ee0c596cb82054650dfa32fda51ad35aaa" }, { "url": "https://git.kernel.org/stable/c/dbd126539c098dba3159ce7d34b10b2daddcbd0f" }, { "url": "https://git.kernel.org/stable/c/63feb687e89a3a52a31e6e01764117cc500f1974" }, { "url": "https://git.kernel.org/stable/c/160045fc943f6c46b227644261252c8a22b8a87a" }, { "url": "https://git.kernel.org/stable/c/b30771b69eafae750afb7385fbcc3d77ed3f3670" }, { "url": "https://git.kernel.org/stable/c/1627e7d5c9b09721a141d07cedb178882f1ded67" }, { "url": "https://git.kernel.org/stable/c/1a638c55f2db6cb2296e5e3138015dd8fd9d4aa9" }, { "url": "https://git.kernel.org/stable/c/a4f27ad055392fa164f5649e89a3637b033c5fcc" } ], "title": "smb: client: fix overflow in passthrough ioctl bounds check", "x_generator": { "engine": "bippy-1.2.0" } } } }