{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64048", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.029Z", "datePublished": "2026-07-19T15:39:32.664Z", "dateUpdated": "2026-08-23T12:45:32.597Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:32.597Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot\n\nOn the SMC-D client, slot 0 of ini->ism_dev[]/ini->ism_chid[] is\nreserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt()\npopulates V2 entries starting at index 1, so when no V1 device is\nselected slot 0 is left in its kzalloc()'ed state with ism_dev[0] ==\nNULL and ism_chid[0] == 0.\n\nsmc_v2_determine_accepted_chid() then matches the peer's CHID against\nthe array starting from index 0 using the CHID alone. A malicious\npeer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches\nthe empty slot, ini->ism_selected becomes 0, and the subsequent\nism_dev[0]->lgr_lock dereference in smc_conn_create() faults at\noffsetof(struct smcd_dev, lgr_lock) == 0x68:\n\n BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0\n Write of size 4 at addr 0000000000000068 by task exploit/144\n Call Trace:\n _raw_spin_lock_bh\n smc_conn_create (net/smc/smc_core.c:1997)\n __smc_connect (net/smc/af_smc.c:1447)\n smc_connect (net/smc/af_smc.c:1720)\n __sys_connect\n __x64_sys_connect\n do_syscall_64\n\nRequire ism_dev[i] to be non-NULL before accepting a CHID match." } ], "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 - The fault is triggered while processing a malicious CLC ACCEPT message received from a remote TCP peer during the SMC-D handshake; the attacker controls the server response over the network.\nAC:L - Once a victim with SMC-Dv2 hardware initiates an SMC connection, a malicious peer can reliably send `d1.chid == 0` in the CLC ACCEPT to match the empty reserved slot 0 without races or special timing.\nPR:N - No local privileges are required on the victim host; an unauthenticated remote attacker operating a malicious SMC server can crash connecting clients, and unprivileged users can create SMC sockets without capability checks.\nUI:N - Exploitation requires only that a victim application initiate a normal outbound SMC connection to the attacker's server, which occurs automatically in enterprise middleware without per-connection user action.\nS:U - The vulnerability causes a kernel crash on the victim host but does not cross a security boundary such as VM escape or sandbox breakout.\nC:N - The bug is a null pointer dereference when taking `ism_dev[0]->lgr_lock`; it causes an immediate kernel fault with no information disclosure.\nI:N - The attempted write at address 0x68 is a spinlock operation on a NULL `smcd_dev` pointer, not a controlled or arbitrary memory modification primitive.\nA:H - A successful trigger causes a kernel null pointer dereference (KASAN-reported oops/panic), crashing the affected system or at minimum the connecting process's kernel context." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/smc/af_smc.c" ], "versions": [ { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "903f7688ffeb9b323d70652c01f554bd4ba2a3d6", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "6927cacf2b10d4fa80c1a2d407512ef9397c59c6", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "53eb7bd09aace72fa17510d80e0caf5ca058c231", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "afa9036b8c9963947b487c36e332df6a42c96fcb", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e", "status": "affected", "versionType": "git" }, { "version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7", "lessThan": "277740023def559a4a2ddc3e8e784ee37a0f16a9", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/smc/af_smc.c" ], "versions": [ { "version": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "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": "5.10", "versionEndExcluding": "5.10.266" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.217" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/903f7688ffeb9b323d70652c01f554bd4ba2a3d6" }, { "url": "https://git.kernel.org/stable/c/dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0" }, { "url": "https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6" }, { "url": "https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0" }, { "url": "https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231" }, { "url": "https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb" }, { "url": "https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e" }, { "url": "https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9" } ], "title": "net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot", "x_generator": { "engine": "bippy-1.2.0" } } } }