net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot
Priority LOW 39CWE-476Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 16 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-476.
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00501 43rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.266, 5.15.217, 6.1.175 +5Red Hat: 4 advisoriesRed Hat: 16 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.10 and later | 5.10.266, 5.15.217, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 5.10 and later Fixed in 5.10.266, 5.15.217, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.10 to before 5.10.266; 5.11 to before 5.15.217; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.10 to before 5.10.266; 5.11 to before 5.15.217; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.266, 5.15.217, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1
Red Hat 4 advisories
- RHSA-2026:88477 Released 2026-10-23 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- 10Base-SMTV kernel-modules-internal-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.68.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.68.1.el10_2, kernel-64k-devel-6.12.0-211.68.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.68.1.el10_2, kernel-64k-6.12.0-211.68.1.el10_2, kernel-64k-core-6.12.0-211.68.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.68.1.el10_2, libperf-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-64k-6.12.0-211.68.1.el10_2, kernel-rt-64k-core-6.12.0-211.68.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-core-6.12.0-211.68.1.el10_2, kernel-rt-debug-6.12.0-211.68.1.el10_2 +9
- RHSA-2026:57252 Released 2026-08-20 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.41.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.41.1.el9_8, kernel-64k-devel-5.14.0-687.41.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.41.1.el9_8, kernel-64k-5.14.0-687.41.1.el9_8, kernel-64k-core-5.14.0-687.41.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.41.1.el9_8, libperf-5.14.0-687.41.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.41.1.el9_8, kernel-rt-64k-5.14.0-687.41.1.el9_8, kernel-rt-64k-core-5.14.0-687.41.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.41.1.el9_8, kernel-rt-core-5.14.0-687.41.1.el9_8, kernel-rt-debug-5.14.0-687.41.1.el9_8 +9
- RHSA-2026:57253 Released 2026-08-20 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.157.1.el8_10, kernel-4.18.0-553.157.1.el8_10, kernel-abi-stablelists-4.18.0-553.157.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.157.1.el8_10
Show 1 more Red Hat advisories
- RHSA-2026:57254 Released 2026-08-20 · Red Hat rating Importantkernel-rt security, bug fix, and enhancement update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.157.1.rt7.498.el8_10, kernel-rt-core-4.18.0-553.157.1.rt7.498.el8_10, kernel-rt-debug-4.18.0-553.157.1.rt7.498.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.157.1.rt7.498.el8_10, kernel-rt-core-4.18.0-553.157.1.rt7.498.el8_10, kernel-rt-debug-4.18.0-553.157.1.rt7.498.el8_10 +7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| 10Base-SMTV | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:57253 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:57253 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux Hidden (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:57254 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:57254 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:57252 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64048
- 2026-10-03 Alias added: GHSA-942p-vjp4-xm8p
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-23 Fix available: RHSA-2026:88477 · Red Hat
- 2026-10-23 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · Red Hat
- 2026-10-27 CVSS score changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/903f7688ffeb9b323d70652c01f554bd4ba2a3d6
- https://git.kernel.org/stable/c/dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0
- https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6
- https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0
- https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231
- https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb
- https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e
- https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9
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Sources
- CVE-2026-64048 · CVE Program
- CVE-2026-64048 · NVD
- FIRST EPSS
- GHSA-942p-vjp4-xm8p · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64048 · Red Hat security data · CC BY 4.0
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