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Miller" , Jakub Kicinski , Jesper Dangaard Brouer , Shuah Khan , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Stanislav Fomichev , Jiayuan Chen , Varun R Mallya , Ihor Solodrai , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH bpf-next v4 1/2] bpf, sockmap: disallow update and delete from tc, xdp, socket_filter and flow_dissector Message-ID: References: <20260630145410.3648099-1-rhkrqnwk98@gmail.com> <20260630145410.3648099-2-rhkrqnwk98@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20260630145410.3648099-2-rhkrqnwk98@gmail.com> On Tue, Jun 30, 2026 at 02:54:05PM +0000, Sechang Lim wrote: >sock_map_update_common() and __sock_map_delete() hold stab->lock and call >sock_map_unref() -> sock_map_del_link(), which takes sk_callback_lock for >write. That gives the order stab->lock -> sk_callback_lock. > >The reverse order comes from the SK_SKB stream parser. >sk_psock_strp_data_ready() holds sk_callback_lock for read, and after the >verdict tcp_bpf_strp_read_sock() acks the consumed data inline via >__tcp_cleanup_rbuf(). The ACK goes out egress, where a sched_cls program >deletes from the sockmap and takes stab->lock: > > WARNING: possible circular locking dependency detected [...] >A tc, xdp, socket_filter or flow_dissector program has no reason to >update or delete a sockmap, and redirect does not go through here. Drop >them from may_update_sockmap() so the verifier rejects it. It also >closes the matching sockhash inversion. > >Suggested-by: John Fastabend >Signed-off-by: Sechang Lim >--- Great lets get this merged and we will separately fix the sockops issue reported by the bots. Reviewed-by: John Fastabend