{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64141", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.037Z", "datePublished": "2026-07-19T15:40:33.890Z", "dateUpdated": "2026-08-05T12:39:41.570Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:41.570Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix null pointer dereference in compare_guid_key()\n\nsession_fd_check() walks the per-inode m_op_list during durable-handle\nsession teardown and sets op->conn = NULL for every opinfo whose conn\nmatched the closing session's connection. The matching opinfo, however,\nstays linked in its per-ClientGuid lease_table_list entry's lb->lease_list\nbecause destroy_lease_table() only runs on full TCP-connection teardown,\nnot on SESSION_LOGOFF.\n\nIf the same TCP connection then negotiates a fresh session with the\nsame ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and\nis unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a\nlease context on a different inode, find_same_lease_key() walks\nlb->lease_list, reaches the stale opinfo, and calls compare_guid_key(),\nwhich unconditionally dereferences opinfo->conn->ClientGUID. The conn\npointer is NULL and the kernel panics.\n\nReproducer requires only a successful SMB2 SESSION_SETUP and a share\nconfigured with 'durable handles = yes'. KASAN report on mainline\n70390501d194:\n\n general protection fault, probably for non-canonical address\n 0xdffffc0000000069: 0000 [#1] SMP KASAN PTI\n KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f]\n Workqueue: ksmbd-io handle_ksmbd_work\n RIP: 0010:bcmp+0x5b/0x230\n Call Trace:\n compare_guid_key+0x4b/0xd0\n find_same_lease_key+0x324/0x690\n smb2_open+0x6aea/0x8e60\n handle_ksmbd_work+0x796/0xee0\n ...\n\nFaulting address 0x348 is the offset of ClientGUID within struct\nksmbd_conn, confirming opinfo->conn was NULL.\n\nRead opinfo->conn once and bail out if it has been cleared by a\nconcurrent session_fd_check(). A half-detached opinfo cannot be the\nowner of an active lease, so returning 0 is the correct match result." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - ksmbd is an in-kernel SMB server on TCP/445; the crash is triggered by remote SMB2 packets processed in `handle_ksmbd_work()` without local access.\nAC:L - The attacker fully controls the deterministic sequence (durable CREATE with lease, SESSION_LOGOFF, SESSION_SETUP on the same TCP connection, CREATE with lease on another file); no race or timing dependency beyond attacker-driven requests.\nPR:N - Exploitation requires only network reachability to ksmbd and completion of SMB2 SESSION_SETUP (including guest/anonymous where permitted); no prior Linux OS privileges or capabilities are needed on the host.\nUI:N - No victim user action is required beyond the attacker sending crafted SMB2 protocol messages to the server.\nS:U - Impact is a kernel oops/panic within the ksmbd server context; it does not cross a security boundary such as guest-to-host escape or sandbox breakout.\nC:N - The fault is a NULL pointer dereference in `bcmp()` at offset 0x348 into `struct ksmbd_conn`; the invalid read faults before any data is returned to the attacker.\nI:N - There is no memory corruption or write primitive—only a read through a NULL `opinfo->conn` pointer that immediately triggers a kernel fault.\nA:H - A remotely triggerable NULL dereference in kernel workqueue context causes a general protection fault/kernel oops, enabling repeatable denial of service against the host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/oplock.c" ], "versions": [ { "version": "8df4bcdb0a4232192b2445256c39b787d58ef14d", "lessThan": "e43cb36d4d7827710cfcd48e95e29a507f0d87be", "status": "affected", "versionType": "git" }, { "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "0836081b394ca074d1b910f2b990ff7b4b4404c7", "status": "affected", "versionType": "git" }, { "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad", "status": "affected", "versionType": "git" }, { "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "af86896ca3239e25a6bd7d352213371265073d38", "status": "affected", "versionType": "git" }, { "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "4b83cbc4c15f09b000cc06f033f64b0824b6dc87", "status": "affected", "versionType": "git" }, { "version": "6.6.32", "lessThan": "6.6.142", "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/server/oplock.c" ], "versions": [ { "version": "6.9", "status": "affected" }, { "version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "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": "6.6.32", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e43cb36d4d7827710cfcd48e95e29a507f0d87be" }, { "url": "https://git.kernel.org/stable/c/0836081b394ca074d1b910f2b990ff7b4b4404c7" }, { "url": "https://git.kernel.org/stable/c/cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad" }, { "url": "https://git.kernel.org/stable/c/af86896ca3239e25a6bd7d352213371265073d38" }, { "url": "https://git.kernel.org/stable/c/4b83cbc4c15f09b000cc06f033f64b0824b6dc87" } ], "title": "ksmbd: fix null pointer dereference in compare_guid_key()", "x_generator": { "engine": "bippy-1.2.0" } } } }