On 8/11/26 11:55 AM, Yuqi Xu wrote:
> Packet processing uses CT limit state under RCU, while netns teardown
> frees that state under ovs_mutex. The CT limit pointer was neither removed
> from readers nor protected by a grace period, allowing packet processing to
> dereference the freed state.
>
> An unprivileged user can trigger this bug from a user and network
> namespace, causing a slab-use-after-free in ovs_ct_execute() when the
> netns is torn down.
>
> Publish the CT limit pointer through RCU, remove it before teardown, and
> wait for readers before freeing its contents. Keep ovs_mutex around
> individual CT limit updates, and use the RCU read-side lock while GET
> traverses the RCU-protected limit lists.
>
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Cc: [email protected]
> Reported-by: Vega <[email protected]>
> Link: https://lore.kernel.org/all/[email protected]
> Assisted-by: Codex:GPT-5.4
> Co-developed-by: Nan Li <[email protected]>
> Signed-off-by: Nan Li <[email protected]>
> Signed-off-by: Yuqi Xu <[email protected]>
> Reviewed-by: Ren Wei <[email protected]>
> ---
> Changes in v5:
>
> - Remove unreachable command-path NULL handling because netlink sockets
> keep their network namespaces alive while requests are processed.
Please, add a note to the commit message on why the NULL checks are not
necessary for the code invoked from netlink handlers. Otherwise, LGTM.
Best regards, Ilya Maximets.
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