AZL-98093
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-98093.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-98093
- Upstream
- Published
- 2026-08-28T08:16:48Z
- Modified
- 2026-08-29T14:18:10.051159514Z
- Summary
- CVE-2026-80634 affecting package kernel 6.6.150.1-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag
The DEVPATHBRVLANUNTAG case post-decrements info->numencaps inside WARNONONCE(). numencaps is u8, so if it's already 0 the decrement still happens and wraps it to 255. The break only leaves the inner switch -- a later path entry can set info->indev back to a real device, and we end up returning with num_encaps == 255.
nftdevforwardpath() then walks info.encap[] (size 2) up to numencaps, which means an OOB stack read and a bogus count copied into the route descriptor.
Should only happen on a malformed bridge path stack, hence the WARN, but worth handling sanely. Move the decrement out of the WARN.
[ While at this, remove the WARNONONCE since this can only happen with a buggy bridge path stack --pablo ].
- References