flow_dissector: do not dissect PPPoE PFC frames

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-46306
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-08 17:16:49 UTC
Updated2026-06-08 17:16:49 UTC
DescriptionIn 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/[email protected]

Risk And Classification

EPSS: 0.000240000 probability, percentile 0.072370000 (date 2026-06-09)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 10f665b52a75df6eb26ddebbbc072ee264183731 e7c811ca372d53c2be7d01a1614e71fae1054836 git Not specified
CNA Linux Linux affected d7e541e86122d21f71eb71c5dfa7fb1eb6623fe8 abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 db104b0d8a7856397c0469d83a4289adf7c54863 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 6044392d9cace3a3672b02c8bc7d38b502e51734 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 0d00b9015069712944934bab09eaa6c542143049 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 7c93f353eab4ea911e394630f07d72e040a729d8 git Not specified
CNA Linux Linux affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 git Not specified
CNA Linux Linux affected 6.0 Not specified
CNA Linux Linux unaffected 6.0 semver Not specified
CNA Linux Linux unaffected 6.1.175 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.140 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.88 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.30 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.7 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1-rc1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report