CVE-2026-68399bpf: Fix UAF in sock clone early bailouts

Official description

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 packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/ac855efc6bb216b262b672af68219e5b731f42a4
• https://git.kernel.org/stable/c/f6814814b3bdd6ecb6bc1fc53ba4e827e0185f01
• https://git.kernel.org/stable/c/24139461545e44442df9b80deace26b2eb3e103d
• https://git.kernel.org/stable/c/01f8a354497ba739f81b691b3702bc4c46500a4d
• https://git.kernel.org/stable/c/14b49b5ab29979552c219a09e569b424fbbf4a6e
• https://git.kernel.org/stable/c/7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f