CVE-2026-68399

Summary

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix UAF in sock clone early bailouts

Similar to recent commit 9b51a6155d14 ("bpf,fork: wipe ->bpf_storage before bailouts that access it"), sk_clone() performs an initial shallow copy of the socket field ->sk_bpf_storage via sock_copy() for the cloned socket newsk.

If sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior to calling bpf_sk_storage_clone(), newsk->sk_bpf_storage still points to the parent socket's BPF local storage. When newsk is subsequently freed via sk_free(), the deallocation path (__sk_destruct() -> bpf_sk_storage_free()) destroys the parent socket's BPF local storage, leading to a use-after-free (UAF) on the parent socket.

Fix this by resetting newsk->sk_bpf_storage to NULL immediately after sock_copy() in sk_clone(), and remove the now redundant initialization from bpf_sk_storage_clone().

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/14b49b5ab29979552c219a09e569b424fbbf4a6e
• https://git.kernel.org/stable/c/7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f

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