CVE-2026-31616

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_phonet: fix skb frags[] overflow in pn_rx_complete() A broken/bored/mean USB host can overflow the skb_shared_info->frags[] array on a Linux gadget exposing a Phonet function by sending an unbounded sequence of full-page OUT transfers. pn_rx_complete() finalizes the skb only when req->actual < req->length, where req->length is set to PAGE_SIZE by the gadget. If the host always sends exactly PAGE_SIZE bytes per transfer, fp->rx.skb will never be reset and each completion will add another fragment via skb_add_rx_frag(). Once nr_frags exceeds MAX_SKB_FRAGS (default 17), subsequent frag stores overwrite memory adjacent to the shinfo on the heap. Drop the skb and account a length error when the frag limit is reached, matching the fix applied in t7xx by commit f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path").

PUBLISHED Reserved 2026-03-09 | Published 2026-04-24 | Updated 2026-04-27 | Assigner Linux

Product status

References

git.kernel.org/...c/9ceff1251904901b0b4e5fe6350fcaffa368ce83

git.kernel.org/...c/c9315ce9da3632c591666a29de82d3e92d46bec1

git.kernel.org/...c/4e476c25bfcab0535ba7c76a903ae77ca8747711

git.kernel.org/...c/bd44ce09b9b569f49ed13e2d87d23d853fc7d6a7

git.kernel.org/...c/66f7471c4042e4eb300e30b5b9d87d1406862673

git.kernel.org/...c/c088d5dd2fffb4de1fb8e7f57751c8b82942180a

cve.org (CVE-2026-31616)

nvd.nist.gov (CVE-2026-31616)

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