CVE-2026-64113

In the Linux kernel, the following vulnerability has been resolved:

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

ixgbevfcleanrx_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:

    devkfreeskb_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 ixgbevfaddrx_frag() on the freed skb, dereferencing

skbshinfo(skb)->nrfrags - 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

(scandropcontinueloops.py + semgrep dropcontinueinloop, 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, kfreeskb, then read skbshinfo(skb)->nr_frags):

  BUG: KASAN: slab-use-after-free in ixgbevfuaftest_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.