Bug 2502541 (CVE-2026-64113)

Summary: CVE-2026-64113 kernel: ixgbevf: fix use-after-free in VEPA multicast source pruning
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedCC: kgrant, rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's ixgbevf network driver. This vulnerability, a use-after-free, occurs when the driver attempts to process network packets for a specific multicast workaround. An attacker could potentially exploit this by sending specially crafted network traffic, which may lead to a system crash, resulting in a denial of service, or in some cases, could allow for arbitrary code execution.
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Description OSIDB Bzimport 2026-07-19 17:05:10 UTC
In the Linux kernel, the following vulnerability has been resolved:

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

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.

Comment 4 errata-xmlrpc 2026-09-08 11:35:20 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:65334 https://access.redhat.com/errata/RHSA-2026:65334

Comment 5 errata-xmlrpc 2026-09-10 05:18:41 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:66324 https://access.redhat.com/errata/RHSA-2026:66324

Comment 6 errata-xmlrpc 2026-09-10 05:40:00 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:66325 https://access.redhat.com/errata/RHSA-2026:66325

Comment 7 Jon Orris 2026-09-14 13:36:31 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:67150 https://access.redhat.com/errata/RHSA-2026:67150