CVE-2026-64048net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot
- 7.5HighCVSS base score
- 0.50%Exploitation in 30 daysEPSS · top 56% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.50% · top 56% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < 903f7688ffeb9b323d70652c01f554bd4ba2a3d6
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < 6927cacf2b10d4fa80c1a2d407512ef9397c59c6
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < 53eb7bd09aace72fa17510d80e0caf5ca058c231
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < afa9036b8c9963947b487c36e332df6a42c96fcb
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < 65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e
- affected a7c9c5f4af7f6098da68705fc5d86565d0728ef7 – < 277740023def559a4a2ddc3e8e784ee37a0f16a9
- affected 5.10
- unaffected < 5.10
- unaffected 5.10.266 – ≤ 5.10.*
- unaffected 5.15.217 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.142 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References8
- https://git.kernel.org/stable/c/903f7688ffeb9b323d70652c01f554bd4ba2a3d6 (opens in a new tab)
- https://git.kernel.org/stable/c/dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0 (opens in a new tab)
- https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6 (opens in a new tab)
- https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0 (opens in a new tab)
- https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231 (opens in a new tab)
- https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb (opens in a new tab)
- https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e (opens in a new tab)
- https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45621 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-64048)Record last updated .