FKIE_CVE-2026-64048
Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot
On the SMC-D client, slot 0 of ini->ism_dev[]/ini->ism_chid[] is
reserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt()
populates V2 entries starting at index 1, so when no V1 device is
selected slot 0 is left in its kzalloc()'ed state with ism_dev[0] ==
NULL and ism_chid[0] == 0.
smc_v2_determine_accepted_chid() then matches the peer's CHID against
the array starting from index 0 using the CHID alone. A malicious
peer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches
the empty slot, ini->ism_selected becomes 0, and the subsequent
ism_dev[0]->lgr_lock dereference in smc_conn_create() faults at
offsetof(struct smcd_dev, lgr_lock) == 0x68:
BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0
Write of size 4 at addr 0000000000000068 by task exploit/144
Call Trace:
_raw_spin_lock_bh
smc_conn_create (net/smc/smc_core.c:1997)
__smc_connect (net/smc/af_smc.c:1447)
smc_connect (net/smc/af_smc.c:1720)
__sys_connect
__x64_sys_connect
do_syscall_64
Require ism_dev[i] to be non-NULL before accepting a CHID match.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/smc/af_smc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "6927cacf2b10d4fa80c1a2d407512ef9397c59c6",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
},
{
"lessThan": "d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
},
{
"lessThan": "53eb7bd09aace72fa17510d80e0caf5ca058c231",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
},
{
"lessThan": "afa9036b8c9963947b487c36e332df6a42c96fcb",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
},
{
"lessThan": "65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
},
{
"lessThan": "277740023def559a4a2ddc3e8e784ee37a0f16a9",
"status": "affected",
"version": "a7c9c5f4af7f6098da68705fc5d86565d0728ef7",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/smc/af_smc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.10"
},
{
"lessThan": "5.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.142",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.92",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\u003eism_dev[]/ini-\u003eism_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()\u0027ed state with ism_dev[0] ==\nNULL and ism_chid[0] == 0.\n\nsmc_v2_determine_accepted_chid() then matches the peer\u0027s 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-\u003eism_selected becomes 0, and the subsequent\nism_dev[0]-\u003elgr_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."
}
],
"id": "CVE-2026-64048",
"lastModified": "2026-07-20T15:17:05.553",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-19T16:17:45.190",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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