CVE-2026-43039: net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch
In the Linux kernel, the following vulnerability has been resolved:
net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch
emacdispatchskbzc() allocates a new skb via napiallocskb() but never copies the packet data from the XDP buffer into it. The skb is passed up the stack containing uninitialized heap memory instead of the actual received packet, leaking kernel heap contents to userspace.
Copy the received packet data from the XDP buffer into the skb using skbcopytolineardata().
Additionally, remove the skbmarkforrecycle() call since the skb is backed by the NAPI page frag allocator, not pagepool. Marking a non-pagepool skb for recycle causes the free path to return pages to a pagepool that does not own them, corrupting pagepool state.
The non-ZC path (emacrxpacket) does not have these issues because it uses napibuildskb() to wrap the existing pagepool page directly, requiring no copy, and correctly marks for recycle since the page comes from pagepooldevallocpages().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
In the ZC RX dispatch path (emac_dispatch_skb_zc()), remove the skb_mark_for_recycle() call because the skb is backed by the NAPI page frag allocator (not page_pool).
Linux kernel networking driver (net: ti: icssg-prueth) emac_dispatch_skb_zc() / ZC RX dispatch logic = Remove skb_mark_for_recycle() call
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43039?
CVE-2026-43039 is categorized with a medium severity level.
How do I fix CVE-2026-43039?
To fix CVE-2026-43039, update to the latest version of the Linux kernel that includes the patch for this vulnerability.
What type of vulnerability is CVE-2026-43039?
CVE-2026-43039 is a vulnerability related to missing data copy and improper recycling in zero-copy receive dispatch in the Linux kernel.
Which software versions are affected by CVE-2026-43039?
CVE-2026-43039 affects certain versions of the Linux kernel, particularly those using the net: ti: icssg-prueth driver.
What impact does CVE-2026-43039 have on system security?
The impact of CVE-2026-43039 may lead to data corruption or denial of service in network communications.