xfrm: xfrm_alloc_spi shouldn't use 0 as SPI
In the Linux kernel, the following vulnerability has been resolved: xfrm: xfrm_alloc_spi shouldn't use 0 as SPI x->id.spi == 0 means "no SPI assigned", but since commit 94f39804d891 ("xfrm: Duplicate SPI Handling"), we now create states and add them to the byspi list with this value. __xfrm_state_delete doesn't remove those states from the byspi list, since they shouldn't be there, and this shows up as a UAF the next time we go through the byspi list.
02 / AFFECTED SOFTWARE
Affected packages
898 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: xfrm: xfrm_alloc_spi shouldn't use 0 as SPI x->id.spi == 0 means "no SPI assigned", but since commit 94f39804d891 ("xfrm: Duplicate SPI Handling"), we now create states and add them to the byspi list with this value. __xfrm_state_delete doesn't remove those states from the byspi list, since they shouldn't be there, and this shows up as a UAF the next time we go through the byspi list.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/0baf92d0b1590b903c1f4ead75e61715e50e8146
- https://git.kernel.org/stable/c/9fcedabaae0096f712bbb4ccca6a8538af1cd1c8
- https://git.kernel.org/stable/c/a78e55776522373c446f18d5002a8de4b09e6bf7
- https://git.kernel.org/stable/c/cd8ae32e4e4652db55bce6b9c79267d8946765a9
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39965.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-39965