High · published September 19, 2025
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()").
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 2.6.12.1, < 5.4.299 | 5.4.299 |
| linux/linux_kernel | ≥ 5.5, < 5.10.243 | 5.10.243 |
| linux/linux_kernel | ≥ 5.11, < 5.15.192 | 5.15.192 |
| linux/linux_kernel | ≥ 5.16, < 6.1.151 | 6.1.151 |
| linux/linux_kernel | ≥ 6.2, < 6.6.105 | 6.6.105 |
| linux/linux_kernel | ≥ 6.7, < 6.12.46 | 6.12.46 |
| linux/linux_kernel | ≥ 6.13, < 6.16.6 | 6.16.6 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| debian/debian_linux | all versions | — |