CVE-2026-72057: net/sched: act_ct: preserve tc_skb_cb across defragmentation

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled. Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments().

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

0d76daf2013ce1da20eab5e26bd81d983e1c18fb to < fb080b6f54835d5d4d11ce3122800e6f0f6689e6affected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < 67d6b00a54446c008f52cf70fc0c2ad0c712f85daffected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < 2400c4b05d58834b994500a9eec90a37db44187caffected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < 5c3ae5f6c7c6de73ea9b6a75154fe4ed343e1bacaffected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < b3d835407846134b0d54637c0281b39bebef831daffected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < f7f45ceb855d9ba1cba594fb3f383255f7013fadaffected
ec624fe740b416fb68d536b37fb8eef46f90b5c2 to < 9092e15defbe6c7bc241c306093ca9d358a578e7affected
5.15.13 to < 5.15.217affected

Linux Linux

Default version status: affected

5.16affected
0 to < 5.16unaffected
5.15.217 to ≤ 5.15.*unaffected
6.1.184 to ≤ 6.1.*unaffected
6.6.145 to ≤ 6.6.*unaffected
6.12.97 to ≤ 6.12.*unaffected
6.18.40 to ≤ 6.18.*unaffected
7.1.5 to ≤ 7.1.*unaffected
7.2 to ≤ *unaffected

CVE-2026-72057

net/sched: act_ct: preserve tc_skb_cb across defragmentation

Description

Affected products

Linux Linux

Linux Linux

References