CVE-2024-42108

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux0aeec4bb6a9fc963932bf3c929bdf27d835d44e9 < 4a41bb9f2b402469d425a1c13359d3b3ea4e6403affected
LinuxLinux271e015b91535dd87fd0f5df0cc3b906c2eddef9 < 92cbbe7759193e3418f38d0d73f8fe125312c58baffected
LinuxLinux271e015b91535dd87fd0f5df0cc3b906c2eddef9 < 9a0c28efeec6383ef22e97437616b920e7320b67affected
LinuxLinux6.8affected
LinuxLinux0 < 6.8unaffected
LinuxLinux6.9.9 <= 6.9.*unaffected
LinuxLinux6.10 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References