NuytsTech Security

CVE-2026-46043

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

RDMA/rxe: Validate pad and ICRC before payload_size() in rxe_rcv

rxe_rcv() currently checks only that the incoming packet is at least
header_size(pkt) bytes long before payload_size() is used.

However, payload_size() subtracts both the attacker-controlled BTH pad
field and RXE_ICRC_SIZE from pkt->paylen:

payload_size = pkt->paylen – offset[RXE_PAYLOAD] – bth_pad(pkt)
– RXE_ICRC_SIZE

This means a short packet can still make payload_size() underflow even
if it includes enough bytes for the fixed headers. Simply requiring
header_size(pkt) + RXE_ICRC_SIZE is not sufficient either, because a
packet with a forged non-zero BTH pad can still leave payload_size()
negative and pass an underflowed value to later receive-path users.

Fix this by validating pkt->paylen against the full minimum length
required by payload_size(): header_size(pkt) + bth_pad(pkt) +
RXE_ICRC_SIZE.

More information : https://git.kernel.org/stable/c/2fd4f8b749309a61c3f3f88ee8891d94f79e1240

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