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().
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
References 7
https://git.kernel.org/stable/c/2400c4b05d58834b994500a9eec90a37db44187c
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5c3ae5f6c7c6de73ea9b6a75154fe4ed343e1bac
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9092e15defbe6c7bc241c306093ca9d358a578e7
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b3d835407846134b0d54637c0281b39bebef831d
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f7f45ceb855d9ba1cba594fb3f383255f7013fad
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/67d6b00a54446c008f52cf70fc0c2ad0c712f85d
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/fb080b6f54835d5d4d11ce3122800e6f0f6689e6
416baaa9-dc9f-4396-8d5f-8c081fb06d67