{"id":"DEBIAN-CVE-2024-35981","details":"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 eth0  hfunc 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-\u003erss_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-\u003ebroken = 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-\u003ecvq, &tmp) && \t     !virtqueue_is_broken(vi-\u003ecvq)) \t      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-\u003ebroken`, 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.","modified":"2026-09-15T09:03:14.042592746Z","published":"2024-05-20T10:15:12.617Z","upstream":["CVE-2024-35981"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2024-35981"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.90-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35981.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.8.9-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35981.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.8.9-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35981.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}