发布于3月6日3月6日 Members SUSE: CVE-2024-35981: SUSE Linux Security Advisory Severity 5 CVSS (AV:L/AC:L/Au:S/C:N/I:N/A:C) Published 05/20/2024 Created 06/24/2024 Added 06/24/2024 Modified 01/28/2025 Description In the Linux kernel, the following vulnerability has been resolved: virtio_net: Do not send RSS key if it is not supported There is a bug when setting the RSS options in virtio_net that can break the whole machine, getting the kernel into an infinite loop. Running the following command in any QEMU virtual machine with virtionet will reproduce this problem: # ethtool -X eth0hfunc toeplitz This is how the problem happens: 1) ethtool_set_rxfh() calls virtnet_set_rxfh() 2) virtnet_set_rxfh() calls virtnet_commit_rss_command() 3) virtnet_commit_rss_command() populates 4 entries for the rss scatter-gather 4) Since the command above does not have a key, then the last scatter-gatter entry will be zeroed, since rss_key_size == 0. sg_buf_size = vi->rss_key_size; 5) This buffer is passed to qemu, but qemu is not happy with a buffer with zero length, and do the following in virtqueue_map_desc() (QEMU function): if (!sz) { virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 6) virtio_error() (also QEMU function) set the device as broken vdev->broken = true; 7) Qemu bails out, and do not repond this crazy kernel. 8) The kernel is waiting for the response to come back (function virtnet_send_command()) 9) The kernel is waiting doing the following : while (!virtqueue_get_buf(vi->cvq, &tmp) && !virtqueue_is_broken(vi->cvq)) cpu_relax(); 10) None of the following functions above is true, thus, the kernel loops here forever. Keeping in mind that virtqueue_is_broken() does not look at the qemu `vdev->broken`, so, it never realizes that the vitio is broken at QEMU side. Fix it by not sending RSS commands if the feature is not available in the device. Solution(s) suse-upgrade-cluster-md-kmp-64kb suse-upgrade-cluster-md-kmp-azure suse-upgrade-cluster-md-kmp-default suse-upgrade-cluster-md-kmp-rt suse-upgrade-dlm-kmp-64kb suse-upgrade-dlm-kmp-azure suse-upgrade-dlm-kmp-default suse-upgrade-dlm-kmp-rt suse-upgrade-dtb-allwinner suse-upgrade-dtb-altera suse-upgrade-dtb-amazon suse-upgrade-dtb-amd suse-upgrade-dtb-amlogic suse-upgrade-dtb-apm suse-upgrade-dtb-apple suse-upgrade-dtb-arm suse-upgrade-dtb-broadcom suse-upgrade-dtb-cavium suse-upgrade-dtb-exynos suse-upgrade-dtb-freescale suse-upgrade-dtb-hisilicon suse-upgrade-dtb-lg suse-upgrade-dtb-marvell suse-upgrade-dtb-mediatek suse-upgrade-dtb-nvidia suse-upgrade-dtb-qcom suse-upgrade-dtb-renesas suse-upgrade-dtb-rockchip suse-upgrade-dtb-socionext suse-upgrade-dtb-sprd suse-upgrade-dtb-xilinx suse-upgrade-gfs2-kmp-64kb suse-upgrade-gfs2-kmp-azure suse-upgrade-gfs2-kmp-default suse-upgrade-gfs2-kmp-rt suse-upgrade-kernel-64kb suse-upgrade-kernel-64kb-devel suse-upgrade-kernel-64kb-extra suse-upgrade-kernel-64kb-livepatch-devel suse-upgrade-kernel-64kb-optional suse-upgrade-kernel-azure suse-upgrade-kernel-azure-devel suse-upgrade-kernel-azure-extra suse-upgrade-kernel-azure-livepatch-devel suse-upgrade-kernel-azure-optional suse-upgrade-kernel-azure-vdso suse-upgrade-kernel-debug suse-upgrade-kernel-debug-devel suse-upgrade-kernel-debug-livepatch-devel suse-upgrade-kernel-debug-vdso suse-upgrade-kernel-default suse-upgrade-kernel-default-base suse-upgrade-kernel-default-base-rebuild suse-upgrade-kernel-default-devel suse-upgrade-kernel-default-extra suse-upgrade-kernel-default-livepatch suse-upgrade-kernel-default-livepatch-devel suse-upgrade-kernel-default-optional suse-upgrade-kernel-default-vdso suse-upgrade-kernel-devel suse-upgrade-kernel-devel-azure suse-upgrade-kernel-devel-rt suse-upgrade-kernel-docs suse-upgrade-kernel-docs-html suse-upgrade-kernel-kvmsmall suse-upgrade-kernel-kvmsmall-devel suse-upgrade-kernel-kvmsmall-livepatch-devel suse-upgrade-kernel-kvmsmall-vdso suse-upgrade-kernel-macros suse-upgrade-kernel-obs-build suse-upgrade-kernel-obs-qa suse-upgrade-kernel-rt suse-upgrade-kernel-rt-devel suse-upgrade-kernel-rt-extra suse-upgrade-kernel-rt-livepatch-devel suse-upgrade-kernel-rt-optional suse-upgrade-kernel-rt-vdso suse-upgrade-kernel-rt_debug suse-upgrade-kernel-rt_debug-devel suse-upgrade-kernel-rt_debug-livepatch-devel suse-upgrade-kernel-rt_debug-vdso suse-upgrade-kernel-source suse-upgrade-kernel-source-azure suse-upgrade-kernel-source-rt suse-upgrade-kernel-source-vanilla suse-upgrade-kernel-syms suse-upgrade-kernel-syms-azure suse-upgrade-kernel-syms-rt suse-upgrade-kernel-zfcpdump suse-upgrade-kselftests-kmp-64kb suse-upgrade-kselftests-kmp-azure suse-upgrade-kselftests-kmp-default suse-upgrade-kselftests-kmp-rt suse-upgrade-ocfs2-kmp-64kb suse-upgrade-ocfs2-kmp-azure suse-upgrade-ocfs2-kmp-default suse-upgrade-ocfs2-kmp-rt suse-upgrade-reiserfs-kmp-64kb suse-upgrade-reiserfs-kmp-azure suse-upgrade-reiserfs-kmp-default suse-upgrade-reiserfs-kmp-rt References https://attackerkb.com/topics/cve-2024-35981 CVE - 2024-35981
