CVE-2025-39848
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ax25: properly unshare skbs in ax25_kiss_rcv() Bernard Pidoux reported a regression apparently caused by commit c353e8983e0d ("net: introduce per netns packet chains"). skb->dev becomes NULL and we crash in __netif_receive_skb_core(). Before above commit, different kind of bugs or corruptions could happen without a major crash. But the root cause is that ax25_kiss_rcv() can queue/mangle input skb without checking if this skb is shared or not. Many thanks to Bernard Pidoux for his help, diagnosis and tests. We had a similar issue years ago fixed with commit 7aaed57c5c28 ("phonet: properly unshare skbs in phonet_rcv()").
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-09-19 16:15:43.640000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-09-19T16:15:43.640",
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nax25: properly unshare skbs in ax25_kiss_rcv()\n\nBernard Pidoux reported a regression apparently caused by commit\nc353e8983e0d (\"net: introduce per netns packet chains\").\n\nskb->dev becomes NULL and we crash in __netif_receive_skb_core().\n\nBefore above commit, different kind of bugs or corruptions could happen\nwithout a major crash.\n\nBut the root cause is that ax25_kiss_rcv() can queue/mangle input skb\nwithout checking if this skb is shared or not.\n\nMany thanks to Bernard Pidoux for his help, diagnosis and tests.\n\nWe had a similar issue years ago fixed with commit 7aaed57c5c28\n(\"phonet: properly unshare skbs in phonet_rcv()\")."
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"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nax25: descompartir correctamente los skbs en ax25_kiss_rcv()\n\nBernard Pidoux informó de una regresión aparentemente causada por el commit\nc353e8983e0d ('net: introduce per netns packet chains').\n\nskb->dev se vuelve NULL y nos caemos en __netif_receive_skb_core().\n\nAntes del commit anterior, diferentes tipos de errores o corrupciones podían ocurrir\nsin un bloqueo importante.\n\nPero la causa raíz es que ax25_kiss_rcv() puede encolar/manipular el skb de entrada\nsin verificar si este skb está compartido o no.\n\nMuchas gracias a Bernard Pidoux por su ayuda, diagnóstico y pruebas.\n\nTuvimos un problema similar hace años solucionado con el commit 7aaed57c5c28\n('phonet: properly unshare skbs in phonet_rcv()')."
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