Bug 2464393 (CVE-2026-43039)

Summary: CVE-2026-43039 kernel: net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's `icssg-prueth` network driver. This vulnerability allows for information disclosure, where uninitialized kernel memory contents can be exposed to user applications. This occurs because the driver fails to properly copy received packet data into a network buffer before passing it up the system's network stack. This could allow a local user to access sensitive system information.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-05-01 15:04:13 UTC 
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().
Comment 1 Keith Grant 2026-05-01 18:00:31 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050103-CVE-2026-43039-ff5c@gregkh/T