CVE-2024-35981
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2024-35981
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-35981.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-35981
- Downstream
- Related
- Published
- 2024-05-20T09:42:05Z
- Modified
- 2025-10-17T06:25:39.059945Z
- Summary
- virtio_net: Do not send RSS key if it is not supported
- 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 toeplitzThis is how the problem happens:
1) ethtoolsetrxfh() calls virtnetsetrxfh()
2) virtnetsetrxfh() calls virtnetcommitrss_command()
3) virtnetcommitrss_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 rsskeysize == 0. sgbufsize = vi->rsskeysize;
5) This buffer is passed to qemu, but qemu is not happy with a buffer with zero length, and do the following in virtqueuemapdesc() (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 virtnetsendcommand())
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 virtqueueisbroken() 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.
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/059a49aa2e25c58f90b50151f109dd3c4cdb3a47
- https://git.kernel.org/stable/c/28e9a64638cd16bc1ecac9ff74ffeacb9fb652de
- https://git.kernel.org/stable/c/43a71c1b4b3a6d4db857b1435d271540279fc7de
- https://git.kernel.org/stable/c/539a2b995a4ed93125cb0efae0f793b00ab2158b
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedc7114b1249fa3b5f3a434606ba4cc89c4a27d618Fixed539a2b995a4ed93125cb0efae0f793b00ab2158b
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedc7114b1249fa3b5f3a434606ba4cc89c4a27d618Fixed43a71c1b4b3a6d4db857b1435d271540279fc7de
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedc7114b1249fa3b5f3a434606ba4cc89c4a27d618Fixed28e9a64638cd16bc1ecac9ff74ffeacb9fb652de
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedc7114b1249fa3b5f3a434606ba4cc89c4a27d618Fixed059a49aa2e25c58f90b50151f109dd3c4cdb3a47