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").
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Linux kernel Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | 6.6.136 |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.85-1 |
| sid | Fixed | 6.19.14-1 |
| forky | Fixed | 6.19.14-1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
References
- https://git.kernel.org/stable/c/4e476c25bfcab0535ba7c76a903ae77ca8747711
- https://git.kernel.org/stable/c/66f7471c4042e4eb300e30b5b9d87d1406862673
- https://git.kernel.org/stable/c/9ceff1251904901b0b4e5fe6350fcaffa368ce83
- https://git.kernel.org/stable/c/bd44ce09b9b569f49ed13e2d87d23d853fc7d6a7
- https://git.kernel.org/stable/c/c088d5dd2fffb4de1fb8e7f57751c8b82942180a
- https://git.kernel.org/stable/c/c9315ce9da3632c591666a29de82d3e92d46bec1
- https://www.suse.com/security/cve/CVE-2026-31616.html
- https://security-tracker.debian.org/tracker/CVE-2026-31616
- https://git.kernel.org/stable/c/3d7f7e0c842242878c24b2facff8d6eda23ee1e9
- https://git.kernel.org/stable/c/7424f0287da73d3d8c5fa5e9d25d26fce762708e
- https://git.kernel.org/stable/c/b5ec49fa198bd08967a3102bd41f53ccadce72c9
CWEs
CWE-401
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.