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 --- drivers/md/md-cluster.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 drivers/md/md-cluster.h (limited to 'drivers/md/md-cluster.h') diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h new file mode 100644 index 000000000..8fb06d853 --- /dev/null +++ b/drivers/md/md-cluster.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + + +#ifndef _MD_CLUSTER_H +#define _MD_CLUSTER_H + +#include "md.h" + +struct mddev; +struct md_rdev; + +struct md_cluster_operations { + struct md_submodule_head head; + + int (*join)(struct mddev *mddev, int nodes); + int (*leave)(struct mddev *mddev); + int (*slot_number)(struct mddev *mddev); + int (*resync_info_update)(struct mddev *mddev, sector_t lo, sector_t hi); + int (*resync_start_notify)(struct mddev *mddev); + int (*resync_status_get)(struct mddev *mddev); + void (*resync_info_get)(struct mddev *mddev, sector_t *lo, sector_t *hi); + int (*metadata_update_start)(struct mddev *mddev); + int (*metadata_update_finish)(struct mddev *mddev); + void (*metadata_update_cancel)(struct mddev *mddev); + int (*resync_start)(struct mddev *mddev); + int (*resync_finish)(struct mddev *mddev); + int (*area_resyncing)(struct mddev *mddev, int direction, sector_t lo, sector_t hi); + int (*add_new_disk)(struct mddev *mddev, struct md_rdev *rdev); + void (*add_new_disk_cancel)(struct mddev *mddev); + int (*new_disk_ack)(struct mddev *mddev, bool ack); + int (*remove_disk)(struct mddev *mddev, struct md_rdev *rdev); + void (*load_bitmaps)(struct mddev *mddev, int total_slots); + int (*gather_bitmaps)(struct md_rdev *rdev); + int (*resize_bitmaps)(struct mddev *mddev, sector_t newsize, sector_t oldsize); + int (*lock_all_bitmaps)(struct mddev *mddev); + void (*unlock_all_bitmaps)(struct mddev *mddev); + void (*update_size)(struct mddev *mddev, sector_t old_dev_sectors); +}; + +extern int md_setup_cluster(struct mddev *mddev, int nodes); +extern void md_cluster_stop(struct mddev *mddev); +extern void md_reload_sb(struct mddev *mddev, int raid_disk); + +#endif /* _MD_CLUSTER_H */ -- cgit v1.3.1