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CVE-2026-64113

ixgbevf: fix use-after-free in VEPA multicast source pruning

9.8 EPSS 0.5% AV:N

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

ReleaseStatus VersionWhat this means
Debian 12bookwormfixed6.1.176-1Update the kernel and reboot. Fixed in 6.1.176-1. A running kernel keeps the old code until the machine restarts.
Debian 13trixiefixed6.12.94-1Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts.
Debian 14forkyfixed7.0.12-1Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesidfixed7.0.12-1Update 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 ixgbevf

Prints 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

IntroducedFixed inCommit
3.195.10.2583d931ac62411
3.195.15.2096ef30384a50a
3.196.1.17555b3e91d62b2
3.196.6.142add70e2682c0
3.196.12.92a244395d8c56
3.196.18.34dfef79e09ed2
3.197.0.11e8768bcbe5cd
3.197.15d49b568c188

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.