CVE-2025-21692

Published Feb 10, 2025

Last updated 22 days ago

CVSS high 7.8
Linux Kernel

Overview

AI description

Automated description summarized from trusted sources.

CVE-2025-21692 is an out-of-bounds indexing vulnerability within the Enhanced Transmission Selection (ETS) scheduler component of the Linux kernel. Discovered by Haowei Yan, the vulnerability occurs in the `etsclassfrom_arg()` function when it receives a class ID (clid) of 0, leading to an array-index-out-of-bounds error. The vulnerability affects Linux kernel versions from 5.6 through 6.13-rc7. The vulnerability exists in the `net/sched/sch_ets.c` file, where the `etsclassfromarg()` function can index an out-of-bounds class when passed a clid of 0. This can potentially allow a local attacker to escalate their privileges and gain unauthorized access to sensitive system resources.

Description
In the Linux kernel, the following vulnerability has been resolved: net: sched: fix ets qdisc OOB Indexing Haowei Yan <g1042620637@gmail.com> found that ets_class_from_arg() can index an Out-Of-Bound class in ets_class_from_arg() when passed clid of 0. The overflow may cause local privilege escalation. [ 18.852298] ------------[ cut here ]------------ [ 18.853271] UBSAN: array-index-out-of-bounds in net/sched/sch_ets.c:93:20 [ 18.853743] index 18446744073709551615 is out of range for type 'ets_class [16]' [ 18.854254] CPU: 0 UID: 0 PID: 1275 Comm: poc Not tainted 6.12.6-dirty #17 [ 18.854821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 18.856532] Call Trace: [ 18.857441] <TASK> [ 18.858227] dump_stack_lvl+0xc2/0xf0 [ 18.859607] dump_stack+0x10/0x20 [ 18.860908] __ubsan_handle_out_of_bounds+0xa7/0xf0 [ 18.864022] ets_class_change+0x3d6/0x3f0 [ 18.864322] tc_ctl_tclass+0x251/0x910 [ 18.864587] ? lock_acquire+0x5e/0x140 [ 18.865113] ? __mutex_lock+0x9c/0xe70 [ 18.866009] ? __mutex_lock+0xa34/0xe70 [ 18.866401] rtnetlink_rcv_msg+0x170/0x6f0 [ 18.866806] ? __lock_acquire+0x578/0xc10 [ 18.867184] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 18.867503] netlink_rcv_skb+0x59/0x110 [ 18.867776] rtnetlink_rcv+0x15/0x30 [ 18.868159] netlink_unicast+0x1c3/0x2b0 [ 18.868440] netlink_sendmsg+0x239/0x4b0 [ 18.868721] ____sys_sendmsg+0x3e2/0x410 [ 18.869012] ___sys_sendmsg+0x88/0xe0 [ 18.869276] ? rseq_ip_fixup+0x198/0x260 [ 18.869563] ? rseq_update_cpu_node_id+0x10a/0x190 [ 18.869900] ? trace_hardirqs_off+0x5a/0xd0 [ 18.870196] ? syscall_exit_to_user_mode+0xcc/0x220 [ 18.870547] ? do_syscall_64+0x93/0x150 [ 18.870821] ? __memcg_slab_free_hook+0x69/0x290 [ 18.871157] __sys_sendmsg+0x69/0xd0 [ 18.871416] __x64_sys_sendmsg+0x1d/0x30 [ 18.871699] x64_sys_call+0x9e2/0x2670 [ 18.871979] do_syscall_64+0x87/0x150 [ 18.873280] ? do_syscall_64+0x93/0x150 [ 18.874742] ? lock_release+0x7b/0x160 [ 18.876157] ? do_user_addr_fault+0x5ce/0x8f0 [ 18.877833] ? irqentry_exit_to_user_mode+0xc2/0x210 [ 18.879608] ? irqentry_exit+0x77/0xb0 [ 18.879808] ? clear_bhb_loop+0x15/0x70 [ 18.880023] ? clear_bhb_loop+0x15/0x70 [ 18.880223] ? clear_bhb_loop+0x15/0x70 [ 18.880426] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 18.880683] RIP: 0033:0x44a957 [ 18.880851] Code: ff ff e8 fc 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 8974 24 10 [ 18.881766] RSP: 002b:00007ffcdd00fad8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 18.882149] RAX: ffffffffffffffda RBX: 00007ffcdd010db8 RCX: 000000000044a957 [ 18.882507] RDX: 0000000000000000 RSI: 00007ffcdd00fb70 RDI: 0000000000000003 [ 18.885037] RBP: 00007ffcdd010bc0 R08: 000000000703c770 R09: 000000000703c7c0 [ 18.887203] R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000001 [ 18.888026] R13: 00007ffcdd010da8 R14: 00000000004ca7d0 R15: 0000000000000001 [ 18.888395] </TASK> [ 18.888610] ---[ end trace ]---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-129
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-129

Social media

Hype score
Not currently trending
  1. Linux kernel just got another dangerous patch - CVE-2025-21692 (CVSS3.1 7.8); if you run kernels 5.6 - 6.13 rc, patch now or assume compromise. ๐Ÿงต Here's what happened... https://t.co/WrURejLrkc

    @dispatchy_ai

    3 Oct 2025

    27 Impressions

    0 Retweets

    2 Likes

    0 Bookmarks

    1 Reply

    0 Quotes

  2. ๐Ÿšจ #CVE-2025-21692: The VSOCK Vulnerability Unlocking #Linux Kernel Privileges https://t.co/FdJsZ8rpHH Educational Purposes!

    @UndercodeUpdate

    29 Sept 2025

    70 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  3. Linuxใ‚ซใƒผใƒใƒซใฎEnhanced Transmission Selection (ETS)ใซใŠใ‘ใ‚‹ใ€้ ้š”ใ‚ณใƒผใƒ‰ๅฎŸ่กŒใŒๅฏ่ƒฝใช่„†ๅผฑๆ€งCVE-2025-21692ใซใคใ„ใฆใ€‚ใƒญใ‚ธใƒƒใ‚ฏไธๅ‚™ใ€‚ใ‚ฏใƒฉใ‚นIDใŒ0ใซใชใ‚‹ใ“ใจใŒใ‚ใ‚Šๅพ—ใ‚‹ใ“ใจใฎ่ฆ‹่ฝใจใ—ใซใ‚ˆใ‚‹ๅขƒ็•Œๅค–ใƒกใƒขใƒช่ชญใฟ่พผใฟใ€‚ https:/

    @__kokumoto

    18 Sept 2025

    968 Impressions

    1 Retweet

    7 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  4. CRITICAL VULNERABILITY ALERT A new RCE flaw (CVE-2025-21692) in the Linux kernel allows for full host compromise. Patches are availableโ€”act now! https://t.co/cgIMRZlzhe https://t.co/n0M2u0zTOT

    @cyberbivash

    18 Sept 2025

    1 Impression

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  5. Ello, I recently wrote a writeup for CVE-2025-21692, an out of bounds access in the ETS qdisc, https://t.co/wmO4pudZrR. Was curious to see any corrections or feedback ppl may have as im not tremendously well versed in kernel exploitation and would love some pointers. Tq

    @movx64

    16 Sept 2025

    49 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  6. Proof of concept source code and misc files for my CVE-2025-21692 exploit, kernel version 6.6.75 https://t.co/YVN6i3JqmR

    @Dinosn

    16 Sept 2025

    3973 Impressions

    16 Retweets

    60 Likes

    28 Bookmarks

    0 Replies

    0 Quotes

  7. GitHub - volticks/CVE-2025-21692-poc: Proof of concept source code and misc files for my CVE-2025-21692 exploit, kernel version 6.6.75 https://t.co/9Miq0vbr4b

    @akaclandestine

    15 Sept 2025

    2746 Impressions

    9 Retweets

    26 Likes

    18 Bookmarks

    0 Replies

    0 Quotes

  8. GitHub - volticks/CVE-2025-21692-poc: Proof of concept source code and misc files for my CVE-2025-21692 exploit, kernel version 6.6.75 - https://t.co/IFkx3bUHKG

    @piedpiper1616

    15 Sept 2025

    4387 Impressions

    22 Retweets

    66 Likes

    29 Bookmarks

    0 Replies

    0 Quotes

  9. ๐Ÿšจ CVE-2025-21692 โ“ ๐Ÿข Linux - Linux ๐Ÿ—๏ธ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 ๐Ÿ”— https://t.co/f7C2dL0HV4 ๐Ÿ”— https://t.co/KbXcTRx3IZ ๐Ÿ”— https://t.co/npfS0ArzRW ๐Ÿ”— https://t.co/ossSsM5XQg ๐Ÿ”— https://t.co/Ja49ZI0wWy ๐Ÿ”— https://t.co/ROGuvOA9mx #CyberCron #VulnAlert https://t.co/

    @cybercronai

    13 Feb 2025

    23 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  10. ๐Ÿšจ CVE-2025-21692 โ“ ๐Ÿข Linux - Linux ๐Ÿ—๏ธ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 ๐Ÿ”— https://t.co/f7C2dL0HV4 ๐Ÿ”— https://t.co/KbXcTRx3IZ ๐Ÿ”— https://t.co/npfS0ArzRW ๐Ÿ”— https://t.co/ossSsM5XQg ๐Ÿ”— https://t.co/Ja49ZI0wWy ๐Ÿ”— https://t.co/ROGuvOA9mx #CyberCron #VulnAlert https://t.co/p

    @cybercronai

    10 Feb 2025

    19 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT This resolves the follow splat and lock-up when running with PREEMPT_RT enabled on Hyper-V: [ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002 [ 415.140822] INFO: lockdep is turned off. [ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery pmt_class intel_pmc_ssram_telemetry intel_vsec ghash_clmulni_intel aesni_intel rapl binfmt_misc nls_ascii nls_cp437 vfat fat snd_pcm hyperv_drm snd_timer drm_client_lib drm_shmem_helper snd sg soundcore drm_kms_helper pcspkr hv_balloon hv_utils evdev joydev drm configfs efi_pstore nfnetlink vsock_loopback vmw_vsock_virtio_transport_common hv_sock vmw_vsock_vmci_transport vsock vmw_vmci efivarfs autofs4 ext4 crc16 mbcache jbd2 sr_mod sd_mod cdrom hv_storvsc serio_raw hid_generic scsi_transport_fc hid_hyperv scsi_mod hid hv_netvsc hyperv_keyboard scsi_common [ 415.140846] Preemption disabled at: [ 415.140847] [<ffffffffc0656171>] storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc] [ 415.140854] CPU: 8 UID: 0 PID: 1048 Comm: stress-ng-iomix Not tainted 6.19.0-rc7 #30 PREEMPT_{RT,(full)} [ 415.140856] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/04/2024 [ 415.140857] Call Trace: [ 415.140861] <TASK> [ 415.140861] ? storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc] [ 415.140863] dump_stack_lvl+0x91/0xb0 [ 415.140870] __schedule_bug+0x9c/0xc0 [ 415.140875] __schedule+0xdf6/0x1300 [ 415.140877] ? rtlock_slowlock_locked+0x56c/0x1980 [ 415.140879] ? rcu_is_watching+0x12/0x60 [ 415.140883] schedule_rtlock+0x21/0x40 [ 415.140885] rtlock_slowlock_locked+0x502/0x1980 [ 415.140891] rt_spin_lock+0x89/0x1e0 [ 415.140893] hv_ringbuffer_write+0x87/0x2a0 [ 415.140899] vmbus_sendpacket_mpb_desc+0xb6/0xe0 [ 415.140900] ? rcu_is_watching+0x12/0x60 [ 415.140902] storvsc_queuecommand+0x669/0xbe0 [hv_storvsc] [ 415.140904] ? HARDIRQ_verbose+0x10/0x10 [ 415.140908] ? __rq_qos_issue+0x28/0x40 [ 415.140911] scsi_queue_rq+0x760/0xd80 [scsi_mod] [ 415.140926] __blk_mq_issue_directly+0x4a/0xc0 [ 415.140928] blk_mq_issue_direct+0x87/0x2b0 [ 415.140931] blk_mq_dispatch_queue_requests+0x120/0x440 [ 415.140933] blk_mq_flush_plug_list+0x7a/0x1a0 [ 415.140935] __blk_flush_plug+0xf4/0x150 [ 415.140940] __submit_bio+0x2b2/0x5c0 [ 415.140944] ? submit_bio_noacct_nocheck+0x272/0x360 [ 415.140946] submit_bio_noacct_nocheck+0x272/0x360 [ 415.140951] ext4_read_bh_lock+0x3e/0x60 [ext4] [ 415.140995] ext4_block_write_begin+0x396/0x650 [ext4] [ 415.141018] ? __pfx_ext4_da_get_block_prep+0x10/0x10 [ext4] [ 415.141038] ext4_da_write_begin+0x1c4/0x350 [ext4] [ 415.141060] generic_perform_write+0x14e/0x2c0 [ 415.141065] ext4_buffered_write_iter+0x6b/0x120 [ext4] [ 415.141083] vfs_write+0x2ca/0x570 [ 415.141087] ksys_write+0x76/0xf0 [ 415.141089] do_syscall_64+0x99/0x1490 [ 415.141093] ? rcu_is_watching+0x12/0x60 [ 415.141095] ? finish_task_switch.isra.0+0xdf/0x3d0 [ 415.141097] ? rcu_is_watching+0x12/0x60 [ 415.141098] ? lock_release+0x1f0/0x2a0 [ 415.141100] ? rcu_is_watching+0x12/0x60 [ 415.141101] ? finish_task_switch.isra.0+0xe4/0x3d0 [ 415.141103] ? rcu_is_watching+0x12/0x60 [ 415.141104] ? __schedule+0xb34/0x1300 [ 415.141106] ? hrtimer_try_to_cancel+0x1d/0x170 [ 415.141109] ? do_nanosleep+0x8b/0x160 [ 415.141111] ? hrtimer_nanosleep+0x89/0x100 [ 415.141114] ? __pfx_hrtimer_wakeup+0x10/0x10 [ 415.141116] ? xfd_validate_state+0x26/0x90 [ 415.141118] ? rcu_is_watching+0x12/0x60 [ 415.141120] ? do_syscall_64+0x1e0/0x1490 [ 415.141121] ? do_syscall_64+0x1e0/0x1490 [ 415.141123] ? rcu_is_watching+0x12/0x60 [ 415.141124] ? do_syscall_64+0x1e0/0x1490 [ 415.141125] ? do_syscall_64+0x1e0/0x1490 [ 415.141127] ? irqentry_exit+0x140/0 ---truncated---โ€ขCVE-2026-43475