CVE-2025-71133

In the Linux kernel, the following vulnerability has been resolved:

RDMA/irdma: avoid invalid read in irdma_net_event

irdma_net_event() should not dereference anything from neigh (alias ptr) until it has checked that the event is NETEVENT_NEIGH_UPDATE. Other events come with different structures pointed to by ptr and they may be smaller than struct neighbour.

Move the read of neigh->dev under the NETEVENT_NEIGH_UPDATE case.

The bug is mostly harmless, but it triggers KASAN on debug kernels:

BUG: KASAN: stack-out-of-bounds in irdma_net_event+0x32e/0x3b0 [irdma] Read of size 8 at addr ffffc900075e07f0 by task kworker/27:2/542554

CPU: 27 PID: 542554 Comm: kworker/27:2 Kdump: loaded Not tainted 5.14.0-630.el9.x86_64+debug #1 Hardware name: […] Workqueue: events rt6_probe_deferred Call Trace: dump_stack_lvl+0x60/0xb0 print_address_description.constprop.0+0x2c/0x3f0 print_report+0xb4/0x270 kasan_report+0x92/0xc0 irdma_net_event+0x32e/0x3b0 [irdma] notifier_call_chain+0x9e/0x180 atomic_notifier_call_chain+0x5c/0x110 rt6_do_redirect+0xb91/0x1080 tcp_v6_err+0xe9b/0x13e0 icmpv6_notify+0x2b2/0x630 ndisc_redirect_rcv+0x328/0x530 icmpv6_rcv+0xc16/0x1360 ip6_protocol_deliver_rcu+0xb84/0x12e0 ip6_input_finish+0x117/0x240 ip6_input+0xc4/0x370 ipv6_rcv+0x420/0x7d0 __netif_receive_skb_one_core+0x118/0x1b0 process_backlog+0xd1/0x5d0 __napi_poll.constprop.0+0xa3/0x440 net_rx_action+0x78a/0xba0 handle_softirqs+0x2d4/0x9c0 do_softirq+0xad/0xe0

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/305c02e541befe4a44ffde30ed374970f41aeb6c
• https://git.kernel.org/stable/c/6f05611728e9d0ab024832a4f1abb74a5f5d0bb0
• https://git.kernel.org/stable/c/bf197c7c79ef6458d1ee84dd7db251b51784885f
• https://git.kernel.org/stable/c/d9b9affd103f51b42322da4ed5ac025b560bc354
• https://git.kernel.org/stable/c/db93ae6fa66f1c61ae63400191195e3ee58021da
• https://git.kernel.org/stable/c/fc23d05f0b3fb4d80657e7afebae2cae686b31c8