CVE-2026-46306 (GCVE-0-2026-46306)
Vulnerability from cvelistv5
Published
2026-06-08 15:46
Modified
2026-06-08 15:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
flow_dissector: do not dissect PPPoE PFC frames
RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT
RECOMMENDED for PPPoE. In practice, pppd does not support negotiating
PFC for PPPoE sessions, and the flow dissector driver has assumed an
uncompressed frame until the blamed commit.
During the review process of that commit [1], support for PFC is
suggested. However, having a compressed (1-byte) protocol field means
the subsequent PPP payload is shifted by one byte, causing 4-byte
misalignment for the network header and an unaligned access exception
on some architectures.
The exception can be reproduced by sending a PPPoE PFC frame to an
ethernet interface of a MIPS board, with RPS enabled, even if no PPPoE
session is active on that interface:
$ 0 : 00000000 80c40000 00000000 85144817
$ 4 : 00000008 00000100 80a75758 81dc9bb8
$ 8 : 00000010 8087ae2c 0000003d 00000000
$12 : 000000e0 00000039 00000000 00000000
$16 : 85043240 80a75758 81dc9bb8 00006488
$20 : 0000002f 00000007 85144810 80a70000
$24 : 81d1bda0 00000000
$28 : 81dc8000 81dc9aa8 00000000 805ead08
Hi : 00009d51
Lo : 2163358a
epc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50
ra : 805ead08 __skb_get_hash_net+0x74/0x12c
Status: 11000403 KERNEL EXL IE
Cause : 40800010 (ExcCode 04)
BadVA : 85144817
PrId : 0001992f (MIPS 1004Kc)
Call Trace:
[<805e91f0>] __skb_flow_dissect+0x1b0/0x1b50
[<805ead08>] __skb_get_hash_net+0x74/0x12c
[<805ef330>] get_rps_cpu+0x1b8/0x3fc
[<805fca70>] netif_receive_skb_list_internal+0x324/0x364
[<805fd120>] napi_complete_done+0x68/0x2a4
[<8058de5c>] mtk_napi_rx+0x228/0xfec
[<805fd398>] __napi_poll+0x3c/0x1c4
[<805fd754>] napi_threaded_poll_loop+0x234/0x29c
[<805fd848>] napi_threaded_poll+0x8c/0xb0
[<80053544>] kthread+0x104/0x12c
[<80002bd8>] ret_from_kernel_thread+0x14/0x1c
Code: 02d51821 1060045b 00000000 <8c640000> 3084000f 2c820005 144001a2 00042080 8e220000
To reduce the attack surface and maintain performance, do not process
PPPoE PFC frames.
[1] https://lore.kernel.org/r/20220630231016.GA392@debian.home
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 10f665b52a75df6eb26ddebbbc072ee264183731 Version: d7e541e86122d21f71eb71c5dfa7fb1eb6623fe8 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 Version: 46126db9c86110e5fc1e369b9bb89735ddefdae4 |
||
{
"containers": {
"cna": {
"affected": [
{
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"product": "Linux",
"programFiles": [
"net/core/flow_dissector.c"
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],
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"vendor": "Linux",
"versions": [
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"version": "6.0"
},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "6.6.140",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.88",
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},
{
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"status": "unaffected",
"version": "6.18.30",
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},
{
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"status": "unaffected",
"version": "7.0.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
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},
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}
],
"negate": false,
"operator": "OR"
}
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}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nflow_dissector: do not dissect PPPoE PFC frames\n\nRFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT\nRECOMMENDED for PPPoE. In practice, pppd does not support negotiating\nPFC for PPPoE sessions, and the flow dissector driver has assumed an\nuncompressed frame until the blamed commit.\n\nDuring the review process of that commit [1], support for PFC is\nsuggested. However, having a compressed (1-byte) protocol field means\nthe subsequent PPP payload is shifted by one byte, causing 4-byte\nmisalignment for the network header and an unaligned access exception\non some architectures.\n\nThe exception can be reproduced by sending a PPPoE PFC frame to an\nethernet interface of a MIPS board, with RPS enabled, even if no PPPoE\nsession is active on that interface:\n\n$ 0 : 00000000 80c40000 00000000 85144817\n$ 4 : 00000008 00000100 80a75758 81dc9bb8\n$ 8 : 00000010 8087ae2c 0000003d 00000000\n$12 : 000000e0 00000039 00000000 00000000\n$16 : 85043240 80a75758 81dc9bb8 00006488\n$20 : 0000002f 00000007 85144810 80a70000\n$24 : 81d1bda0 00000000\n$28 : 81dc8000 81dc9aa8 00000000 805ead08\nHi : 00009d51\nLo : 2163358a\nepc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50\nra : 805ead08 __skb_get_hash_net+0x74/0x12c\nStatus: 11000403 KERNEL EXL IE\nCause : 40800010 (ExcCode 04)\nBadVA : 85144817\nPrId : 0001992f (MIPS 1004Kc)\nCall Trace:\n[\u003c805e91f0\u003e] __skb_flow_dissect+0x1b0/0x1b50\n[\u003c805ead08\u003e] __skb_get_hash_net+0x74/0x12c\n[\u003c805ef330\u003e] get_rps_cpu+0x1b8/0x3fc\n[\u003c805fca70\u003e] netif_receive_skb_list_internal+0x324/0x364\n[\u003c805fd120\u003e] napi_complete_done+0x68/0x2a4\n[\u003c8058de5c\u003e] mtk_napi_rx+0x228/0xfec\n[\u003c805fd398\u003e] __napi_poll+0x3c/0x1c4\n[\u003c805fd754\u003e] napi_threaded_poll_loop+0x234/0x29c\n[\u003c805fd848\u003e] napi_threaded_poll+0x8c/0xb0\n[\u003c80053544\u003e] kthread+0x104/0x12c\n[\u003c80002bd8\u003e] ret_from_kernel_thread+0x14/0x1c\n\nCode: 02d51821 1060045b 00000000 \u003c8c640000\u003e 3084000f 2c820005 144001a2 00042080 8e220000\n\nTo reduce the attack surface and maintain performance, do not process\nPPPoE PFC frames.\n\n[1] https://lore.kernel.org/r/20220630231016.GA392@debian.home"
}
],
"providerMetadata": {
"dateUpdated": "2026-06-08T15:46:33.936Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836"
},
{
"url": "https://git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200"
},
{
"url": "https://git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3"
},
{
"url": "https://git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863"
},
{
"url": "https://git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734"
},
{
"url": "https://git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049"
},
{
"url": "https://git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8"
},
{
"url": "https://git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473"
}
],
"title": "flow_dissector: do not dissect PPPoE PFC frames",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-46306",
"datePublished": "2026-06-08T15:46:33.936Z",
"dateReserved": "2026-05-13T15:03:33.111Z",
"dateUpdated": "2026-06-08T15:46:33.936Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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