Description
In the Linux kernel, the following vulnerability has been resolved:

net: thunderbolt: Fix frags[] overflow by bounding frame_count

tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The
first frame goes into the skb linear area and every further frame is added as
a page fragment.

skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
page, hdr_size, frame_size,
TBNET_RX_PAGE_SIZE - hdr_size);

A packet of frame_count frames therefore ends up with frame_count - 1
fragments. tbnet_check_frame() only bounds the peer supplied frame_count to
TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A
peer that sends a packet of 19 or more small frames pushes nr_frags past
MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and
corrupts memory after the shared info.

Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never
produce more fragments than frags[] can hold. This matches the recent skb
frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net:
wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc
("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").
Published: 2026-08-15
Score: n/a
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

No vendor fix or workaround currently provided.

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History

Sat, 15 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: thunderbolt: Fix frags[] overflow by bounding frame_count tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment. skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, hdr_size, frame_size, TBNET_RX_PAGE_SIZE - hdr_size); A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info. Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").
Title net: thunderbolt: Fix frags[] overflow by bounding frame_count
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-15T05:53:26.718Z

Reserved: 2026-08-09T03:40:39.909Z

Link: CVE-2026-72157

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:21:33.497

Modified: 2026-08-15T06:21:33.497

Link: CVE-2026-72157

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-15T09:30:04Z

Weaknesses

No weakness.