CVE-2026-80986
In the Linux kernel, the following vulnerability has been resolved:
net/smc: bound the peer rkey counts in SMC-Rv2 LLC messages
On a link whose device has max_recv_sge == 1 there is no shared v2 receive buffer, and smc_llc_save_add_link_rkeys() takes the v2 extension from 44 bytes past the start of the queue entry's inline message:
The entry is a 72-byte allocation and the extension starts at offset 68, so ext->num_rkeys at offset 94 is already past it. This happens on every SMC-Rv2 link addition, whatever the peer sends:
Detalles técnicos trazas, registros y código del informe original
ext = (struct smc_llc_msg_add_link_v2_ext *)(llc_msg + SMC_WR_TX_SIZE); [ 2.490065] BUG: KASAN: slab-out-of-bounds in smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490431] Read of size 2 at addr ffff8880056406de by task smctest/106 [ 2.490709] [ 2.490792] CPU: 0 UID: 0 PID: 106 Comm: smctest Not tainted 7.2.0-rc5-p1-g77a5d9d9c99f #32 PREEMPT(lazy) [ 2.490795] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 2.490798] Call Trace: [ 2.490803] <TASK> [ 2.490805] dump_stack_lvl+0x53/0x70 [ 2.490810] print_report+0xd0/0x630 [ 2.490828] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 2.490832] ? smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490834] kasan_report+0xce/0x100 [ 2.490836] ? smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490837] smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490839] ? smcr_buf_map_lgr+0x1bf/0x2b0 [ 2.490844] smc_llc_cli_add_link+0xca7/0x1e80 [ 2.490848] ? smc_llc_wait+0x355/0x810 [ 2.490850] ? __pfx_smc_llc_wait+0x10/0x10 [ 2.490851] ? __pfx_smc_llc_cli_add_link+0x10/0x10 [ 2.490853] ? __pfx_autoremove_wake_function+0x10/0x10 [ 2.490863] __smc_connect+0x3f5c/0x4980 [ 2.490873] ? __pfx_kernel_connect+0x10/0x10 [ 2.490888] ? __pfx___smc_connect+0x10/0x10 [ 2.490891] ? release_sock+0x148/0x1d0 [ 2.490894] smc_connect+0x42c/0x580 [ 2.490896] __sys_connect+0xfc/0x130 [ 2.490898] ? __pfx___sys_connect+0x10/0x10 [ 2.490900] ? handle_mm_fault+0x1a1/0x430 [ 2.490908] __x64_sys_connect+0x6d/0xb0 [ 2.490909] ? fpregs_assert_state_consistent+0x56/0xe0 [ 2.490917] do_syscall_64+0xf9/0x540 [ 2.490921] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 2.490924] RIP: 0033:0x421bb4 [ 2.490927] Code: ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d ad 34 09 00 00 74 13 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 55 [ 2.490929] RSP: 002b:00007ffd473b01a8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a [ 2.490935] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000421bb4 [ 2.490936] RDX: 0000000000000010 RSI: 00007ffd473b01d0 RDI: 0000000000000003 [ 2.490937] RBP: 0000000000003930 R08: 0000000000000004 R09: 0000000000000000 [ 2.490938] R10: 00007ffd473b0f98 R11: 0000000000000202 R12: 0000000000000006 [ 2.490939] R13: 00007ffd473b0f87 R14: 0000000000000003 R15: 00007ffd473b0f90 [ 2.490940] </TASK> [ 2.490941] [ 2.499545] Allocated by task 44: [ 2.499693] kasan_save_stack+0x33/0x60 [ 2.499860] kasan_save_track+0x14/0x30 [ 2.500026] __kasan_kmalloc+0x8f/0xa0 [ 2.500190] __kmalloc_cache_noprof+0x158/0x370 [ 2.500393] smc_llc_enqueue+0x72/0x560 [ 2.500559] smc_wr_rx_tasklet_fn+0x474/0xa80 [ 2.500747] tasklet_action_common+0x20f/0x8a0 [ 2.500945] handle_softirqs+0x18e/0x590 [ 2.501115] do_softirq+0x3b/0x60 [ 2.501266] __local_bh_enable_ip+0x61/0x70 [ 2.501446] __alloc_skb+0x732/0x890 [ 2.501604] rxe_init_packet+0x16b/0x4f0 [ 2.501783] prepare_ack_packet+0xb8/0x830 [ 2.501962] rxe_receiver+0x495/0x96e0 [ 2.502125] do_work+0x144/0x470 [ 2.502269] process_one_work+0x633/0x1030 [ 2.502450] worker_thread+0x45b/0xd10 [ 2.50261 ---truncated---
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.65%
- Percentil entre todas las CVEs puntuadas: 49
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access75 % - Impacto principal
T1499.004Application or System Exploitationimpact65 % - Impacto secundario
T1068Exploitation for Privilege Escalationprivilege escalation55 %
Vulnerabilidad de desbordamiento de búfer (slab-out-of-bounds) en el kernel de Linux accesible remotamente mediante mensajes SMC-Rv2 (AV:N, PR:N, UI:N). Causa DoS y potencial escalada de privilegios en el contexto del kernel.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-80986",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "27ef6a9981fe74191849966a6d5e0400a4008ab8",
"lessThan": "486c699a8cde82c1d9b4f443eeab4ddf86358cb0",
"versionType": "git"
},
{
"status": "affected",
"version": "27ef6a9981fe74191849966a6d5e0400a4008ab8",
"lessThan": "5e5d9e6df677d30a2203d257b5fd8b99814fa607",
"versionType": "git"
},
{
"status": "affected",
"version": "27ef6a9981fe74191849966a6d5e0400a4008ab8",
"lessThan": "2d1e7c5aaa3326e95e2058457f172ca99a9a4577",
"versionType": "git"
}
],
"programFiles": [
"net/smc/smc_llc.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/smc/smc_llc.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-11T20:19:05.180",
"references": [
{
"url": "https://git.kernel.org/stable/c/2d1e7c5aaa3326e95e2058457f172ca99a9a4577",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/486c699a8cde82c1d9b4f443eeab4ddf86358cb0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5e5d9e6df677d30a2203d257b5fd8b99814fa607",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: bound the peer rkey counts in SMC-Rv2 LLC messages\n\nOn a link whose device has max_recv_sge == 1 there is no shared v2 receive\nbuffer, and smc_llc_save_add_link_rkeys() takes the v2 extension from 44\nbytes past the start of the queue entry's inline message:\n\n ext = (struct smc_llc_msg_add_link_v2_ext *)(llc_msg + SMC_WR_TX_SIZE);\n\nThe entry is a 72-byte allocation and the extension starts at offset 68, so\next->num_rkeys at offset 94 is already past it. This happens on every\nSMC-Rv2 link addition, whatever the peer sends:\n\n [ 2.490065] BUG: KASAN: slab-out-of-bounds in smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.490431] Read of size 2 at addr ffff8880056406de by task smctest/106\n [ 2.490709]\n [ 2.490792] CPU: 0 UID: 0 PID: 106 Comm: smctest Not tainted 7.2.0-rc5-p1-g77a5d9d9c99f #32 PREEMPT(lazy)\n [ 2.490795] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n [ 2.490798] Call Trace:\n [ 2.490803] <TASK>\n [ 2.490805] dump_stack_lvl+0x53/0x70\n [ 2.490810] print_report+0xd0/0x630\n [ 2.490828] ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n [ 2.490832] ? smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.490834] kasan_report+0xce/0x100\n [ 2.490836] ? smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.490837] smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.490839] ? smcr_buf_map_lgr+0x1bf/0x2b0\n [ 2.490844] smc_llc_cli_add_link+0xca7/0x1e80\n [ 2.490848] ? smc_llc_wait+0x355/0x810\n [ 2.490850] ? __pfx_smc_llc_wait+0x10/0x10\n [ 2.490851] ? __pfx_smc_llc_cli_add_link+0x10/0x10\n [ 2.490853] ? __pfx_autoremove_wake_function+0x10/0x10\n [ 2.490863] __smc_connect+0x3f5c/0x4980\n [ 2.490873] ? __pfx_kernel_connect+0x10/0x10\n [ 2.490888] ? __pfx___smc_connect+0x10/0x10\n [ 2.490891] ? release_sock+0x148/0x1d0\n [ 2.490894] smc_connect+0x42c/0x580\n [ 2.490896] __sys_connect+0xfc/0x130\n [ 2.490898] ? __pfx___sys_connect+0x10/0x10\n [ 2.490900] ? handle_mm_fault+0x1a1/0x430\n [ 2.490908] __x64_sys_connect+0x6d/0xb0\n [ 2.490909] ? fpregs_assert_state_consistent+0x56/0xe0\n [ 2.490917] do_syscall_64+0xf9/0x540\n [ 2.490921] entry_SYSCALL_64_after_hwframe+0x77/0x7f\n [ 2.490924] RIP: 0033:0x421bb4\n [ 2.490927] Code: ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d ad 34 09 00 00 74 13 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 55\n [ 2.490929] RSP: 002b:00007ffd473b01a8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a\n [ 2.490935] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000421bb4\n [ 2.490936] RDX: 0000000000000010 RSI: 00007ffd473b01d0 RDI: 0000000000000003\n [ 2.490937] RBP: 0000000000003930 R08: 0000000000000004 R09: 0000000000000000\n [ 2.490938] R10: 00007ffd473b0f98 R11: 0000000000000202 R12: 0000000000000006\n [ 2.490939] R13: 00007ffd473b0f87 R14: 0000000000000003 R15: 00007ffd473b0f90\n [ 2.490940] </TASK>\n [ 2.490941]\n [ 2.499545] Allocated by task 44:\n [ 2.499693] kasan_save_stack+0x33/0x60\n [ 2.499860] kasan_save_track+0x14/0x30\n [ 2.500026] __kasan_kmalloc+0x8f/0xa0\n [ 2.500190] __kmalloc_cache_noprof+0x158/0x370\n [ 2.500393] smc_llc_enqueue+0x72/0x560\n [ 2.500559] smc_wr_rx_tasklet_fn+0x474/0xa80\n [ 2.500747] tasklet_action_common+0x20f/0x8a0\n [ 2.500945] handle_softirqs+0x18e/0x590\n [ 2.501115] do_softirq+0x3b/0x60\n [ 2.501266] __local_bh_enable_ip+0x61/0x70\n [ 2.501446] __alloc_skb+0x732/0x890\n [ 2.501604] rxe_init_packet+0x16b/0x4f0\n [ 2.501783] prepare_ack_packet+0xb8/0x830\n [ 2.501962] rxe_receiver+0x495/0x96e0\n [ 2.502125] do_work+0x144/0x470\n [ 2.502269] process_one_work+0x633/0x1030\n [ 2.502450] worker_thread+0x45b/0xd10\n [ 2.50261\n---truncated---"
}
],
"lastModified": "2026-09-13T07:17:05.417",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}