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TI-2026-45981 Aliases CVE-2026-64417GHSA-fmww-fwc4-2q32

mm: shrinker: fix NULL pointer dereference in debugfs

Priority LOW 24CWE-476Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.

Summary

In the Linux kernel, the following vulnerability has been resolved: mm: shrinker: fix NULL pointer dereference in debugfs shrinker_debugfs_add() creates both "count" and "scan" debugfs files unconditionally. That assumes every shrinker implements both count_objects() and scan_objects(), which is not guaranteed. For example, the xen-backend shrinker sets count_objects() but leaves scan_objects() NULL, so writing to its scan file calls through a NULL function pointer and panics the kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. Call Trace: <TASK> shrinker_debugfs_scan_write+0x12e/0x270 full_proxy_write+0x5f/0x90 vfs_write+0xde/0x420 ? filp_flush+0x75/0x90 ? filp_close+0x1d/0x30 ? do_dup2+0xb8/0x120 ksys_write+0x68/0xf0 ? filp_flush+0x75/0x90 do_syscall_64+0xb3/0x5b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The count path has the same issue in principle if a shrinker omits count_objects(). To fix it, only create "count" and "scan" debugfs files when the corresponding callbacks are present.

Why it matters now

EPSS 0.00123 2nd percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.1.178, 6.6.145, 6.12.96 +3

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.0 and later6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.0 and later Fixed in 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*6.0 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*7.2 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*7.2 rc2VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.0 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:* Versions 7.2 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:* Versions 7.2 rc2 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2

Vendor assessments

Red Hat

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

Not affected: 5 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64417
  2. 2026-10-03 Alias added: GHSA-fmww-fwc4-2q32

References

Patch 6

  • 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