From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/net/af_unix.h | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 include/net/af_unix.h (limited to 'include/net/af_unix.h') diff --git a/include/net/af_unix.h b/include/net/af_unix.h new file mode 100644 index 000000000..bb1b3dee0 --- /dev/null +++ b/include/net/af_unix.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_NET_AFUNIX_H +#define __LINUX_NET_AFUNIX_H + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if IS_ENABLED(CONFIG_UNIX) +struct unix_sock *unix_get_socket(struct file *filp); +#else +static inline struct unix_sock *unix_get_socket(struct file *filp) +{ + return NULL; +} +#endif + +struct unix_address { + refcount_t refcnt; + int len; + struct sockaddr_un name[]; +}; + +struct scm_stat { + atomic_t nr_fds; + unsigned long nr_unix_fds; +}; + +/* The AF_UNIX socket */ +struct unix_sock { + /* WARNING: sk has to be the first member */ + struct sock sk; + struct unix_address *addr; + struct path path; + struct mutex iolock, bindlock; + struct sock *peer; + struct sock *listener; + struct unix_vertex *vertex; + spinlock_t lock; + struct socket_wq peer_wq; +#define peer_wait peer_wq.wait + wait_queue_entry_t peer_wake; + struct scm_stat scm_stat; + int inq_len; + bool recvmsg_inq; + bool scm_rights_notrunc; +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + struct sk_buff *oob_skb; +#endif +}; + +#define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk) +#define unix_peer(sk) (unix_sk(sk)->peer) + +#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock) +#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock) + +#endif -- cgit v1.3.1