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CVE-2026-64113
ixgbevf: fix use-after-free in VEPA multicast source pruning
Published 2026-07-19 (3 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-2026-64113 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 | 6.1.176-1 | Update the kernel and reboot. Fixed in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
ixgbevf_clean_rx_irq() prunes frames whose source MAC matches the VF's own address (VEPA multicast workaround) by freeing the skb and continuing to the next descriptor: dev_kfree_skb_irq(skb); continue; The skb pointer is declared outside the while loop and persists across iterations. Because the continue skips the "skb = NULL" reset at the bottom of the loop, the next iteration enters the "else if (skb)" path and calls ixgbevf_add_rx_frag() on the freed skb, dereferencing skb_shinfo(skb)->nr_frags - a use-after-free in NAPI softirq context. The sibling driver iavf already handles this correctly by nulling the pointer before continuing. Apply the same pattern here. I do not have ixgbevf hardware; the bug was found by static analysis (scan_drop_continue_loops.py + semgrep drop_continue_in_loop, multi-tool corroboration with the highest score in the scan). The UAF was confirmed under KASAN by loading a test module that reproduces the exact code pattern (alloc skb, kfree_skb, then read skb_shinfo(skb)->nr_frags): BUG: KASAN: slab-use-after-free in ixgbevf_uaf_test_init+0x100/0x1000 Read of size 8 at addr 000000006163ae78 by task insmod/30 freed 208-byte region [000000006163adc0, 000000006163ae90) QEMU emulates igb (82576) but not ixgbe (82599), and the igbvf VF driver does not include the VEPA source pruning path, so a full end-to-end reproduction with emulated hardware was not possible.
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/ethernet/intel/ixgbevf/ixgbevf_main.c
- What this is
- INTEL ETHERNET DRIVERSMAINTAINERS section matched on drivers/net/ethernet/intel/*/ · intel-wired-lan@lists.osuosl.org · Maintained
- Kernel module
- ixgbevf
Check it on the machine
grep -wE 'CONFIG_ETHERNET|CONFIG_IXGBEVF|CONFIG_NET_VENDOR_INTEL' /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 ixgbevfPrints 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, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormm
- trixieMnot built on armel/rpi
- forky, sidm
- m
- a loadable module on every flavour - check lsmod, can be blacklisted
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_ETHERNET, CONFIG_IXGBEVF, CONFIG_NET_VENDOR_INTEL
- Reads as
- all on means the file is compiled; any one off means it is not.
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
- 2026-07-19 (3 months ago)source
- CVSS
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.53%, higher than 43.4% 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 |
|---|---|---|
| 3.19 | 5.10.258 | 3d931ac62411 |
| 3.19 | 5.15.209 | 6ef30384a50a |
| 3.19 | 6.1.175 | 55b3e91d62b2 |
| 3.19 | 6.6.142 | add70e2682c0 |
| 3.19 | 6.12.92 | a244395d8c56 |
| 3.19 | 6.18.34 | dfef79e09ed2 |
| 3.19 | 7.0.11 | e8768bcbe5cd |
| 3.19 | 7.1 | 5d49b568c188 |
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:NAttack vector, network
- The bug is in the ixgbevf NAPI receive path triggered by incoming Ethernet frames delivered by the VF hardware; per kernel guidance, driver bugs reachable via received packets are scored as Network.
- AC:LAttack complexity, low
- An attacker can reliably trigger the bug by sending a VEPA-reflected multicast/broadcast frame whose source MAC matches the VF address, then immediately sending a follow-on frame so the next loop iteration reuses the freed skb pointer in the same NAPI poll.
- PR:NPrivileges required, none
- Exploitation requires only the ability to inject crafted L2 frames at the VF (e.g., a co-tenant VM on the same VLAN/cloud segment); no local account or capabilities on the victim system are needed.
- UI:NUser interaction, none
- No victim user action is required; the UAF occurs automatically during softirq packet processing once the crafted frames are received.
- S:UScope, unchanged
- Impact is kernel memory corruption within the same privilege domain (guest or host kernel running the VF driver), not a cross-VM/host security-boundary escape.
- C:HConfidentiality impact, high
- The UAF reads freed slab memory via `skb_shinfo(skb)->nr_frags` in `ixgbevf_add_rx_frag()`, which KASAN confirmed and which can be leveraged for arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- The same UAF path writes into the freed skb through `skb_add_rx_frag()` (fragment metadata, lengths), enabling heap corruption and potential control-flow hijack.
- A:HAvailability impact, high
- Use-after-free in NAPI softirq context can cause kernel oops/panic during receive processing even without full exploitation.