Linux Kernel: ixgbevf UAF in VEPA Multicast Source Pruning
CVE-2026-64113 Published on July 19, 2026
ixgbevf: fix use-after-free in VEPA multicast source pruning
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.
Products Associated with CVE-2026-64113
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Affected Versions
Linux:- Version bad17234ba702a50aeec50ab04724ee58af89607 and below 3d931ac62411a7e43b85dba5fe45e1a4a91bd5cb is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below 6ef30384a50a50e4a484cddf341bc27de31aa3de is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below 55b3e91d62b2f7a24109b2d7c9f4c66d2e3b1ec1 is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below add70e2682c0ad3be2a5810bcf1bc13963ba4df9 is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below a244395d8c563ed1bb26c3ef708db6aeeaa08084 is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below dfef79e09ed2f5df975c98547f97f5d7f8982a24 is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below e8768bcbe5cd30c4ea36a22022c9ffaa66903693 is affected.
- Version bad17234ba702a50aeec50ab04724ee58af89607 and below 5d49b568c188dc77199d8d2b959c91da8cc27cf1 is affected.
- Version 3.19 is affected.
- Before 3.19 is unaffected.
- Version 5.10.258, <= 5.10.* is unaffected.
- Version 5.15.209, <= 5.15.* is unaffected.
- Version 6.1.175, <= 6.1.* is unaffected.
- Version 6.6.142, <= 6.6.* is unaffected.
- Version 6.12.92, <= 6.12.* is unaffected.
- Version 6.18.34, <= 6.18.* is unaffected.
- Version 7.0.11, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.