FKIE_CVE-2026-64210
Vulnerability from fkie_nvd - Published: 2026-07-24 16:16 - Updated: 2026-07-30 15:00
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: xsk: Fix unlocked writing to ICOSQ
During napi poll, when the affinity changes and there's still XSK work
to be done, we trigger an ICOSQ interrupt on the new CPU. However, this
triggering on the ICOSQ is done unprotected.
There are 2 such races:
A) mlx5e_trigger_irq() is called while mlx5e_xsk_alloc_rx_mpwqe() is
running from a different CPU due to affinity change. This can happen
because IRQ triggering is done after napi_complete_done(). At this point
the NAPI can be scheduled on a different CPU. Like this:
CPU A (old affinity, NAPI tail) CPU B (new affinity, fresh NAPI)
------------------------------- --------------------------------
napi_complete_done() clears SCHED
mlx5e_cq_arm(...)
napi_schedule_prep() sets SCHED
mlx5e_napi_poll()
mlx5e_xsk_alloc_rx_mpwqe()
mlx5e_icosq_sync_lock() // noop
memcpy 640 B UMR body
advance sq->pc by 10
mlx5e_trigger_irq(&c->icosq)
wqe_info[pi] = {NOP, 1}
mlx5e_post_nop() advances sq->pc
B) mlx5e_trigger_irq() is called on the ICOSQ when
mlx5e_trigger_napi_icosq() is running.
The obvious fix would be to lock the ICOSQ. But ICOSQ has an optimized
locking scheme that doesn't work for this scenario. Kick the async ICOSQ
instead which is always locked.
This issue was noticed in the wild with the following splat:
netdevice: ge-0-0-1: Bad OP in ICOSQ CQE: 0xd
WARNING: drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:826 [...]
[...]
Call Trace:
<IRQ>
mlx5e_napi_poll+0x11d/0x7f0 [mlx5_core]
__napi_poll+0x30/0x200
? skb_defer_free_flush+0x9c/0xc0
net_rx_action+0x2fe/0x3f0
handle_softirqs+0xd8/0x340
__irq_exit_rcu+0xbc/0xe0
common_interrupt+0x85/0xa0
</IRQ>
<TASK>
asm_common_interrupt+0x26/0x40
[...]
---[ end trace 0000000000000000 ]---
mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2022, qn 0x8f4,
opcode 0xd, syndrome 0x2, vendor syndrome 0x68
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 01 00 68 02 01 00 08 f4 de 14 59 d2
WQE DUMP: WQ size 16384 WQ cur size 0, WQE index 0x1e14, len: 64
00000000: 00 00 00 01 d9 ed 80 02 00 00 00 01 d9 ed 90 02
00000010: 00 00 00 01 d9 ed a0 02 00 00 00 01 d9 ed b0 02
00000020: 00 00 00 01 d9 ed c0 02 00 00 00 01 d9 ed d0 02
00000030: 00 00 00 01 d9 ed e0 02 00 00 00 01 d9 ed f0 02
mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2023, qn 0x8f4,
opcode 0xd, syndrome 0x5, vendor syndrome 0xf9
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 01 00 f9 05 01 00 08 f4 de 15 cf d2
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "8d3b91e7d81000d295cd914d4d9d6f860252e2bf",
"status": "affected",
"version": "db05815b36cbd486c86fd002dfa81c9af6245e25",
"versionType": "git"
},
{
"lessThan": "c326f9c68921e2f14dfcecb2f6b4216313d50248",
"status": "affected",
"version": "db05815b36cbd486c86fd002dfa81c9af6245e25",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"lessThan": "5.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: xsk: Fix unlocked writing to ICOSQ\n\nDuring napi poll, when the affinity changes and there\u0027s still XSK work\nto be done, we trigger an ICOSQ interrupt on the new CPU. However, this\ntriggering on the ICOSQ is done unprotected.\n\nThere are 2 such races:\n\nA) mlx5e_trigger_irq() is called while mlx5e_xsk_alloc_rx_mpwqe() is\nrunning from a different CPU due to affinity change. This can happen\nbecause IRQ triggering is done after napi_complete_done(). At this point\nthe NAPI can be scheduled on a different CPU. Like this:\n\n CPU A (old affinity, NAPI tail) CPU B (new affinity, fresh NAPI)\n ------------------------------- --------------------------------\n napi_complete_done() clears SCHED\n mlx5e_cq_arm(...)\n napi_schedule_prep() sets SCHED\n mlx5e_napi_poll()\n mlx5e_xsk_alloc_rx_mpwqe()\n mlx5e_icosq_sync_lock() // noop\n memcpy 640 B UMR body\n advance sq-\u003epc by 10\n mlx5e_trigger_irq(\u0026c-\u003eicosq)\n wqe_info[pi] = {NOP, 1}\n mlx5e_post_nop() advances sq-\u003epc\n\nB) mlx5e_trigger_irq() is called on the ICOSQ when\nmlx5e_trigger_napi_icosq() is running.\n\nThe obvious fix would be to lock the ICOSQ. But ICOSQ has an optimized\nlocking scheme that doesn\u0027t work for this scenario. Kick the async ICOSQ\ninstead which is always locked.\n\nThis issue was noticed in the wild with the following splat:\n\n netdevice: ge-0-0-1: Bad OP in ICOSQ CQE: 0xd\n WARNING: drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:826 [...]\n [...]\n Call Trace:\n \u003cIRQ\u003e\n mlx5e_napi_poll+0x11d/0x7f0 [mlx5_core]\n __napi_poll+0x30/0x200\n ? skb_defer_free_flush+0x9c/0xc0\n net_rx_action+0x2fe/0x3f0\n handle_softirqs+0xd8/0x340\n __irq_exit_rcu+0xbc/0xe0\n common_interrupt+0x85/0xa0\n \u003c/IRQ\u003e\n \u003cTASK\u003e\n asm_common_interrupt+0x26/0x40\n [...]\n ---[ end trace 0000000000000000 ]---\n mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2022, qn 0x8f4,\n opcode 0xd, syndrome 0x2, vendor syndrome 0x68\n 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000030: 00 00 00 00 01 00 68 02 01 00 08 f4 de 14 59 d2\n WQE DUMP: WQ size 16384 WQ cur size 0, WQE index 0x1e14, len: 64\n 00000000: 00 00 00 01 d9 ed 80 02 00 00 00 01 d9 ed 90 02\n 00000010: 00 00 00 01 d9 ed a0 02 00 00 00 01 d9 ed b0 02\n 00000020: 00 00 00 01 d9 ed c0 02 00 00 00 01 d9 ed d0 02\n 00000030: 00 00 00 01 d9 ed e0 02 00 00 00 01 d9 ed f0 02\n mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2023, qn 0x8f4,\n opcode 0xd, syndrome 0x5, vendor syndrome 0xf9\n 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n 00000030: 00 00 00 00 01 00 f9 05 01 00 08 f4 de 15 cf d2"
}
],
"id": "CVE-2026-64210",
"lastModified": "2026-07-30T15:00:27.343",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-24T16:16:48.623",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/8d3b91e7d81000d295cd914d4d9d6f860252e2bf"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c326f9c68921e2f14dfcecb2f6b4216313d50248"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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