Bug 2482047 (CVE-2026-45929)

Summary: CVE-2026-45929 kernel: ovpn: fix possible use-after-free in ovpn_net_xmit
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `ovpn` module. A use-after-free vulnerability exists in the `ovpn_net_xmit` function where a freed `skb` (socket buffer) pointer can be used for subsequent operations. This can occur when `skb_share_check` frees the original `skb` if it is shared, leading to a stale pointer being used. This flaw could potentially lead to system instability, denial of service, or other unspecified impacts.
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Description OSIDB Bzimport 2026-05-27 15:08:42 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ovpn: fix possible use-after-free in ovpn_net_xmit

When building the skb_list in ovpn_net_xmit, skb_share_check will free
the original skb if it is shared. The current implementation continues
to use the stale skb pointer for subsequent operations:
- peer lookup,
- skb_dst_drop (even though all segments produced by skb_gso_segment
  will have a dst attached),
- ovpn_peer_stats_increment_tx.

Fix this by moving the peer lookup and skb_dst_drop before segmentation
so that the original skb is still valid when used. Return early if all
segments fail skb_share_check and the list ends up empty.
Also switch ovpn_peer_stats_increment_tx to use skb_list.next; the next
patch fixes the stats logic.
Comment 1 Keith Grant 2026-05-28 00:52:38 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052726-CVE-2026-45929-609a@gregkh/T