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TI-2021-22207 Aliases CVE-2021-47559

net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()

Priority LOW 33CWE-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: 4 fixed, 2 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: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk() Coverity reports a possible NULL dereferencing problem: in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) { Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00468 40th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.83, 5.15.6, 5.16Red Hat: 2 advisoriesRed Hat: 4 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.18 and later5.10.83, 5.15.6, 5.16Patch availableCNA
  • Linux VendorLinux Affected 4.18 and later Fixed in 5.10.83, 5.15.6, 5.16 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.18 to before 5.10.83; 5.11 to before 5.15.6VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.18 to before 5.10.83; 5.11 to before 5.15.6 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.83, 5.15.6, 5.16

Red Hat 2 advisories

  • RHSA-2024:6991 Released 2024-09-24 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) kernel-debug-devel-5.14.0-70.117.1.el9_0, kernel-debug-devel-matched-5.14.0-70.117.1.el9_0, kernel-devel-5.14.0-70.117.1.el9_0 +5
    • Red Hat Enterprise Linux BaseOS E4S (v.9.0) bpftool-5.14.0-70.117.1.el9_0, kernel-5.14.0-70.117.1.el9_0, kernel-abi-stablelists-5.14.0-70.117.1.el9_0 +14
  • RHSA-2024:6990 Released 2024-09-24 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt-5.14.0-70.117.1.rt21.189.el9_0, kernel-rt-core-5.14.0-70.117.1.rt21.189.el9_0, kernel-rt-debug-5.14.0-70.117.1.rt21.189.el9_0 +9
    • Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt-5.14.0-70.117.1.rt21.189.el9_0, kernel-rt-core-5.14.0-70.117.1.rt21.189.el9_0, kernel-rt-debug-5.14.0-70.117.1.rt21.189.el9_0 +7

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2024:6991
Red Hat Enterprise Linux BaseOS E4S (v.9.0)Fixed RHSA-2024:6991
Red Hat Enterprise Linux NFV E4S (v.9.0)Fixed RHSA-2024:6990
Red Hat Enterprise Linux Real Time E4S (v.9.0)Fixed RHSA-2024:6990
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47559

References

Patch 3

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences