AZL-109263
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-109263.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-109263
- Upstream
- Published
- 2026-10-18T16:17:09Z
- Modified
- 2026-10-19T14:17:06Z
- Summary
- CVE-2026-98568 affecting package kernel 6.6.157.1-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
vxlan: use one headroom snapshot for neighbour replies
vxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then samples it again to reserve headroom. A concurrent vxlan_changelink() can update needed_headroom between the two reads, creating a TOCTOU race. The second value can exceed the allocation and make the Ethernet header write out of bounds.
The race is reproducible on the unpatched kernel. It occurred when vxlan_na_create() generated a neighbour reply while vxlan_changelink() changed the link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte skbuff_small_head allocation.
Snapshot the headroom once and use that value for both allocation and reservation.
- References