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/trace/misc/fsnotify.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/trace/misc/fsnotify.h (limited to 'include/trace/misc/fsnotify.h') diff --git a/include/trace/misc/fsnotify.h b/include/trace/misc/fsnotify.h new file mode 100644 index 000000000..a201e1bd6 --- /dev/null +++ b/include/trace/misc/fsnotify.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Display helpers for fsnotify events + */ + +#include + +#define show_fsnotify_mask(mask) \ + __print_flags(mask, "|", \ + { FS_ACCESS, "ACCESS" }, \ + { FS_MODIFY, "MODIFY" }, \ + { FS_ATTRIB, "ATTRIB" }, \ + { FS_CLOSE_WRITE, "CLOSE_WRITE" }, \ + { FS_CLOSE_NOWRITE, "CLOSE_NOWRITE" }, \ + { FS_OPEN, "OPEN" }, \ + { FS_MOVED_FROM, "MOVED_FROM" }, \ + { FS_MOVED_TO, "MOVED_TO" }, \ + { FS_CREATE, "CREATE" }, \ + { FS_DELETE, "DELETE" }, \ + { FS_DELETE_SELF, "DELETE_SELF" }, \ + { FS_MOVE_SELF, "MOVE_SELF" }, \ + { FS_OPEN_EXEC, "OPEN_EXEC" }, \ + { FS_UNMOUNT, "UNMOUNT" }, \ + { FS_Q_OVERFLOW, "Q_OVERFLOW" }, \ + { FS_ERROR, "ERROR" }, \ + { FS_OPEN_PERM, "OPEN_PERM" }, \ + { FS_ACCESS_PERM, "ACCESS_PERM" }, \ + { FS_OPEN_EXEC_PERM, "OPEN_EXEC_PERM" }, \ + { FS_PRE_ACCESS, "PRE_ACCESS" }, \ + { FS_MNT_ATTACH, "MNT_ATTACH" }, \ + { FS_MNT_DETACH, "MNT_DETACH" }, \ + { FS_EVENT_ON_CHILD, "EVENT_ON_CHILD" }, \ + { FS_RENAME, "RENAME" }, \ + { FS_DN_MULTISHOT, "DN_MULTISHOT" }, \ + { FS_ISDIR, "ISDIR" }) -- cgit v1.3.1