CVE-2026-43039 net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch
A missing data copy in the TI ICSSG PRUETH driver leaks uninitialized kernel heap memory to userspace, allowing attackers to read sensitive kernel data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43039?
CVE-2026-43039 is a critical vulnerability in Linux kernel, published on 1 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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
emac_dispatch_skb_zc() allocates a new skb via napi_alloc_skb() 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 skb_copy_to_linear_data().
Additionally, remove the skb_mark_for_recycle() call since the skb is backed by the NAPI page frag allocator, not page_pool. Marking a non-page_pool skb for recycle causes the free path to return pages to a page_pool that does not own them, corrupting page_pool state.
The non-ZC path (emac_rx_packet) does not have these issues because it uses napi_build_skb() to wrap the existing page_pool page directly, requiring no copy, and correctly marks for recycle since the page comes from page_pool_dev_alloc_pages().
Which versions are affected by CVE-2026-43039?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43039?
Apply the vendor's patch.
Is CVE-2026-43039 being exploited?
There is no known exploitation of CVE-2026-43039 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-43039, GHSA-958g-8q2h-mvmg, UBUNTU-CVE-2026-43039.