In the Linux kernel, the following vulnerability has been resolved:
RDMA/cma: Allow UD qp_type to join multicast only
As for multicast: - The SIDR is the only mode that makes sense; - Besides PS_UDP, other port spaces like PS_IB is also allowed, as it is UD compatible. In this case qkey also needs to be set [1].
This patch allows only UD qp_type to join multicast, and set qkey to default if it's not set, to fix an uninit-value error: the ib->rec.qkey field is accessed without being initialized.
===================================================== BUG: KMSAN: uninit-value in cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] BUG: KMSAN: uninit-value in cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 cma_iboe_join_multicast drivers/infiniband/core/cma.c:4782 [inline] rdma_join_multicast+0x2b83/0x30a0 drivers/infiniband/core/cma.c:4814 ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479 ucma_join_multicast+0x1e3/0x250 drivers/infiniband/core/ucma.c:1546 ucma_write+0x639/0x6d0 drivers/infiniband/core/ucma.c:1732 vfs_write+0x8ce/0x2030 fs/read_write.c:588 ksys_write+0x28c/0x520 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __ia32_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline] __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
Local variable ib.i created at: cma_iboe_join_multicast drivers/infiniband/core/cma.c:4737 [inline] rdma_join_multicast+0x586/0x30a0 drivers/infiniband/core/cma.c:4814 ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479
CPU: 0 PID: 29874 Comm: syz-executor.3 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 =====================================================
[1] https://lore.kernel.org/linux-rdma/[email protected]/
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade bpftoolUpgrade kernelUpgrade kernel-develUpgrade kernel-tools-develUpgrade kernel-debuginfo-common-aarch64Upgrade perfUpgrade perf-debuginfoUpgrade bpftool-debuginfoUpgrade python-perfUpgrade kernel-headersUpgrade kernel-livepatch-5.15.108-65.141Upgrade python-perf-debuginfoUpgrade kernel-debuginfoUpgrade kernel-toolsUpgrade kernel-tools-debuginfoUpgrade kernel-livepatch-5.10.178-162.673Upgrade kernel-debuginfo-common-x86_64 | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade perfUpgrade perf-debuginfoUpgrade kernel-develUpgrade kernel-libbpfUpgrade kernel-tools-debuginfoUpgrade python3-perfUpgrade kernelUpgrade python3-perf-debuginfoUpgrade bpftoolUpgrade kernel-libbpf-develUpgrade kernel-tools-develUpgrade kernel-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-libbpf-staticUpgrade kernel-headersUpgrade kernel-toolsUpgrade kernel-debuginfo-common-x86_64Upgrade bpftool-debuginfoUpgrade kernel-livepatch-6.1.25-37.47 | Oct 16, 2025 | Oct 1, 2025 |
| Debian | — | Upgrade linux | Oct 3, 2025 | Oct 3, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade kernel-toolsUpgrade kernel-tools-libsUpgrade kernelUpgrade bpftoolUpgrade python3-perfUpgrade kernel-abi-stablelists | Mar 10, 2026 | Mar 10, 2026 |
| Redhat_linux | — | Upgrade kernel-rtNo solution existsUpgrade kernel | Nov 14, 2025 | Oct 1, 2025 |
| Ubuntu | — | Upgrade linux-kvmUpgrade linux-oracleUpgrade linux-intel-iotgUpgrade linux-oracle-5.15Upgrade linux-xilinx-zynqmpUpgrade linux-gkeopUpgrade linux-intel-iotg-5.15Upgrade linux-nvidiaUpgrade linux-gkeUpgrade linux-lowlatencyUpgrade linux-hwe-5.15Upgrade linux-ibmUpgrade linux-riscv-5.15Upgrade linux-azureUpgrade linux-nvidia-tegra-igxUpgrade linux-gcp-5.15Upgrade linux-azure-5.15Upgrade linux-ibm-5.15Upgrade linux-raspiUpgrade linux-intel-iot-realtimeUpgrade linux-aws-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-nvidia-tegraUpgrade linuxUpgrade linux-gcpUpgrade linux-bluefieldUpgrade linux-realtimeUpgrade linux-nvidia-tegra-5.15Upgrade linux-aws | Oct 10, 2025 | Oct 1, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 15, 2025 | Oct 1, 2025 |
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