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CVE-2026-80613
veth: fix NAPI leak in XDP enable error path
Published 2026-08-28 (2 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-80613 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
During XDP enablement in veth, if xdp_rxq_info_reg() or xdp_rxq_info_reg_mem_model() fails, the driver rolls back the changes. However, the rollback loop: for (i--; i >= start; i--) { decrements the loop index 'i' before the first iteration. This correctly skips unregistering the rxq for the failed index 'i' (as registration failed or was already cleaned up), but it also erroneously skips calling netif_napi_deli() for rq[i].xdp_napi. Since netif_napi_add() was already called for index 'i', this leaves a dangling napi_struct in the device's napi_list. When the veth device is later destroyed, the freed queue memory (which contains the leaked NAPI structure) can be reused. The subsequent device teardown iterates the NAPI list and corrupts the reallocated memory, leading to UAF. Fix this by explicitly deleting the NAPI association for the failed index 'i' before rolling back the successfully configured queues.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/veth.c
- What this is
- NETWORKING DRIVERSMAINTAINERS section matched on drivers/net/ · netdev@vger.kernel.org · Maintained
- Kernel module
- veth
Check it on the machine
grep -w CONFIG_VETH /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w vethPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.
- bookworm, trixie, forky, sidm
- m
- a loadable module on every flavour - check lsmod, can be blacklisted
- Build switch
- CONFIG_VETH
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-28 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.18%, higher than 6.7% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.11 | 5.15.212 | fc51373345e7 |
| 5.11 | 6.1.178 | 4559770b2a24 |
| 5.11 | 6.6.145 | 83090f5e7b54 |
| 5.11 | 6.12.97 | d3eb258ad398 |
| 5.11 | 6.18.40 | a9e6707322ef |
| 5.11 | 7.1.5 | 4bd2e5dbe623 |
| 5.11 | 7.2 | 6739027cb72d |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The bug is reached only through local veth/XDP setup syscalls (RTM_NEWLINK/RTM_SETLINK IFLA_XDP and bpf prog load/attach) that call veth_enable_xdp_range(); remote packets and network-facing services never execute this driver registration error-rollback path.
- AC:LAttack complexity, low
- An attacker in a user+network namespace controls the full create/attach/delete sequence and can repeatedly drive the XDP enable error path then RTM_DELLINK teardown; once the NAPI leak occurs, netdev_napi_exit() deterministically dereferences the freed veth_rq-embedded napi_struct.
- PR:LPrivileges required, low
- Triggering requires CAP_NET_ADMIN for veth lifecycle/XDP attach and CAP_BPF to load XDP programs; both are ns_capable() in the netns user_ns and obtainable by an unprivileged local user via unshare -Urn, not init-namespace root.
- UI:NUser interaction, none
- No victim interaction is required; the attacker performs all rtnetlink and BPF syscalls to create the veth pair, attempt XDP enablement, and delete the interface that triggers the latent UAF during netdev teardown.
- S:UScope, unchanged
- Impact is kernel heap corruption and privilege escalation within the same host security authority; it does not cross a VM, container runtime, or IOMMU boundary to affect a separate security domain.
- C:HConfidentiality impact, high
- Leaked NAPI entries leave dangling pointers into freed veth_rq slabs; netdev_napi_exit() iterates napi_list and performs list_del_rcu/gro_cleanup on reallocated memory, a classic UAF enabling arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- The teardown UAF writes through stale napi_struct fields into attacker-influenced heap objects, providing memory corruption primitives that can be developed into arbitrary kernel write and code execution.
- A:HAvailability impact, high
- UAF during free_netdev()/netdev_napi_exit() causes kernel oops/panic on veth deletion; on multi-tenant hosts allowing user namespaces this yields repeatable host-wide denial of service from a container tenant.