Description
In the Linux kernel, the following vulnerability has been resolved:
net: rswitch: Avoid use-after-free in rswitch_poll()
The use-after-free is actually in rswitch_tx_free(), which is inlined in rswitch_poll(). Since `skb` and `gq->skbs[gq->dirty]` are in fact the same pointer, the skb is first freed using dev_kfree_skb_any(), then the value in skb->len is used to update the interface statistics.
Let's move around the instructions to use skb->len before the skb is freed.
This bug is trivial to reproduce using KFENCE. It will trigger a splat every few packets. A simple ARP request or ICMP echo request is enough.
Metrics
CVSS 3.1 5.5/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 0aeec4bb6a9fc963932bf3c929bdf27d835d44e9, < 4a41bb9f2b402469d425a1c13359d3b3ea4e6403; >= 271e015b91535dd87fd0f5df0cc3b906c2eddef9, < 92cbbe7759193e3418f38d0d73f8fe125312c58b; >= 271e015b91535dd87fd0f5df0cc3b906c2eddef9, < 9a0c28efeec6383ef22e97437616b920e7320b67 |
| Linux | Linux | 6.8 |
References
- https://git.kernel.org/stable/c/4a41bb9f2b402469d425a1c13359d3b3ea4e6403Patch
- https://git.kernel.org/stable/c/92cbbe7759193e3418f38d0d73f8fe125312c58bPatch
- https://git.kernel.org/stable/c/9a0c28efeec6383ef22e97437616b920e7320b67Patch
- https://git.kernel.org/stable/c/92cbbe7759193e3418f38d0d73f8fe125312c58bPatch
- https://git.kernel.org/stable/c/9a0c28efeec6383ef22e97437616b920e7320b67Patch
Timeline
- Published
- Jul 30, 2024
- Last modified
- Aug 4, 2026
- NVD status
- Modified