FKIE_CVE-2026-31616
Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-04-24 17:51
Severity ?
Summary
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").
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_phonet: fix skb frags[] overflow in pn_rx_complete()\n\nA broken/bored/mean USB host can overflow the skb_shared_info-\u003efrags[]\narray on a Linux gadget exposing a Phonet function by sending an\nunbounded sequence of full-page OUT transfers.\n\npn_rx_complete() finalizes the skb only when req-\u003eactual \u003c req-\u003elength,\nwhere req-\u003elength is set to PAGE_SIZE by the gadget. If the host always\nsends exactly PAGE_SIZE bytes per transfer, fp-\u003erx.skb will never be\nreset and each completion will add another fragment via\nskb_add_rx_frag(). Once nr_frags exceeds MAX_SKB_FRAGS (default 17),\nsubsequent frag stores overwrite memory adjacent to the shinfo on the\nheap.\n\nDrop the skb and account a length error when the frag limit is reached,\nmatching the fix applied in t7xx by commit f0813bcd2d9d (\"net: wwan:\nt7xx: fix potential skb-\u003efrags overflow in RX path\")."
}
],
"id": "CVE-2026-31616",
"lastModified": "2026-04-24T17:51:40.810",
"metrics": {},
"published": "2026-04-24T15:16:40.870",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4e476c25bfcab0535ba7c76a903ae77ca8747711"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/66f7471c4042e4eb300e30b5b9d87d1406862673"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bd44ce09b9b569f49ed13e2d87d23d853fc7d6a7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c9315ce9da3632c591666a29de82d3e92d46bec1"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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