CVE-2026-74476 (GCVE-0-2026-74476)
Vulnerability from cvelistv5
Published
2026-08-15 12:27
Modified
2026-10-16 19:05
Severity ?
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: veth: convert frag_list skbs before running XDP A frag_list skb can reach veth with data_len set but nr_frags zero. veth_convert_skb_to_xdp_buff() only converts skbs that are shared, locked, have frags[], or do not have enough headroom. It later uses skb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and xdp_frags_size. That exposes frag_list data to XDP as if it were stored in frags[], but frags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment metadata, walk an empty fragment entry, and crash in memcpy() from __xsk_rcv(). Route non-linear skbs through skb_pp_cow_data() before exposing them to XDP, and only advertise XDP frags when the resulting skb has frags[]. skb_copy_bits() already handles frag_list input, and skb_pp_cow_data() builds frags[] output with skb_add_rx_frag(), which is the representation XDP multi-buffer expects.
References
Impacted products
Vendor Product Version
Linux Linux Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
Version: 718a18a0c8a67f97781e40bdef7cdd055c430996
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