CVE-2021-47076

/// Technical description

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

RDMA/rxe: Return CQE error if invalid lkey was supplied

RXE is missing update of WQE status in LOCAL_WRITE failures. This caused

the following kernel panic if someone sent an atomic operation with an

explicitly wrong lkey.

[leonro@vm ~]$ mkt test

test_atomic_invalid_lkey (tests.test_atomic.AtomicTest) ...

WARNING: CPU: 5 PID: 263 at drivers/infiniband/sw/rxe/rxe_comp.c:740 rxe_completer+0x1a6d/0x2e30 [rdma_rxe]

Modules linked in: crc32_generic rdma_rxe ip6_udp_tunnel udp_tunnel rdma_ucm rdma_cm ib_umad ib_ipoib iw_cm ib_cm mlx5_ib ib_uverbs ib_core mlx5_core ptp pps_core

CPU: 5 PID: 263 Comm: python3 Not tainted 5.13.0-rc1+ #2936

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014

RIP: 0010:rxe_completer+0x1a6d/0x2e30 [rdma_rxe]

Code: 03 0f 8e 65 0e 00 00 3b 93 10 06 00 00 0f 84 82 0a 00 00 4c 89 ff 4c 89 44 24 38 e8 2d 74 a9 e1 4c 8b 44 24 38 e9 1c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References