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TI-2025-25594 Aliases CVE-2025-38255GHSA-3574-q5g6-f77j

lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly()

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
Partial Red Hat: 2 without a fix

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

Summary

In the Linux kernel, the following vulnerability has been resolved: lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly() While testing null_blk with configfs, echo 0 > poll_queues will trigger following panic: BUG: kernel NULL pointer dereference, address: 0000000000000010 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 27 UID: 0 PID: 920 Comm: bash Not tainted 6.15.0-02023-gadbdb95c8696-dirty #1238 PREEMPT(undef) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:__bitmap_or+0x48/0x70 Call Trace: <TASK> __group_cpus_evenly+0x822/0x8c0 group_cpus_evenly+0x2d9/0x490 blk_mq_map_queues+0x1e/0x110 null_map_queues+0xc9/0x170 [null_blk] blk_mq_update_queue_map+0xdb/0x160 blk_mq_update_nr_hw_queues+0x22b/0x560 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_poll_queues_store+0xa4/0x130 [null_blk] configfs_write_iter+0x109/0x1d0 vfs_write+0x26e/0x6f0 ksys_write+0x79/0x180 __x64_sys_write+0x1d/0x30 x64_sys_call+0x45c4/0x45f0 do_syscall_64+0xa5/0x240 entry_SYSCALL_64_after_hwframe+0x76/0x7e Root cause is that numgrps is set to 0, and ZERO_SIZE_PTR is returned from kcalloc(), and later ZERO_SIZE_PTR will be deferenced. Fix the problem by checking numgrps first in group_cpus_evenly(), and return NULL directly if numgrps is zero. [[email protected]: also fix the non-SMP version]

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00166 5th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.6.96, 6.12.36, 6.15.5 +1Red Hat: 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
LinuxLinux6.3 and later6.6.96, 6.12.36, 6.15.5, 6.16Patch availableCNA
  • Linux VendorLinux Affected 6.3 and later Fixed in 6.6.96, 6.12.36, 6.15.5, 6.16 Patch available CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*6.3 to before 6.6.96; 6.7 to before 6.12.36; 6.13 to before 6.15.5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*6.16 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*6.16 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*6.16 rc3VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.3 to before 6.6.96; 6.7 to before 6.12.36; 6.13 to before 6.15.5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* Versions 6.16 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* Versions 6.16 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* Versions 6.16 rc3 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.6.96, 6.12.36, 6.15.5, 6.16

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Not affected: 4 products
  • 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-2025-38255
  2. 2026-10-03 Alias added: GHSA-3574-q5g6-f77j
  3. 2026-10-29 Affected versions changed · Red Hat
  4. 2026-11-05 CISA SSVC decision points changed

References

Patch 4

  • 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