GHSA-942P-VJP4-XM8P
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31In 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.
{
"affected": [],
"aliases": [
"CVE-2026-64048"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:45Z",
"severity": "HIGH"
},
"details": "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": "GHSA-942p-vjp4-xm8p",
"modified": "2026-07-20T15:31:57Z",
"published": "2026-07-19T18:31:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64048"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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