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 --- fs/dlm/util.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 fs/dlm/util.c (limited to 'fs/dlm/util.c') diff --git a/fs/dlm/util.c b/fs/dlm/util.c new file mode 100644 index 000000000..f2bc401f3 --- /dev/null +++ b/fs/dlm/util.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-only +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved. +** +** +******************************************************************************* +******************************************************************************/ + +#include "dlm_internal.h" +#include "rcom.h" +#include "util.h" + +#define DLM_ERRNO_EDEADLK 35 +#define DLM_ERRNO_EBADR 53 +#define DLM_ERRNO_EBADSLT 57 +#define DLM_ERRNO_EPROTO 71 +#define DLM_ERRNO_EOPNOTSUPP 95 +#define DLM_ERRNO_ETIMEDOUT 110 +#define DLM_ERRNO_EINPROGRESS 115 + +/* higher errno values are inconsistent across architectures, so select + one set of values for on the wire */ + +int to_dlm_errno(int err) +{ + switch (err) { + case -EDEADLK: + return -DLM_ERRNO_EDEADLK; + case -EBADR: + return -DLM_ERRNO_EBADR; + case -EBADSLT: + return -DLM_ERRNO_EBADSLT; + case -EPROTO: + return -DLM_ERRNO_EPROTO; + case -EOPNOTSUPP: + return -DLM_ERRNO_EOPNOTSUPP; + case -ETIMEDOUT: + return -DLM_ERRNO_ETIMEDOUT; + case -EINPROGRESS: + return -DLM_ERRNO_EINPROGRESS; + } + return err; +} + +int from_dlm_errno(int err) +{ + switch (err) { + case -DLM_ERRNO_EDEADLK: + return -EDEADLK; + case -DLM_ERRNO_EBADR: + return -EBADR; + case -DLM_ERRNO_EBADSLT: + return -EBADSLT; + case -DLM_ERRNO_EPROTO: + return -EPROTO; + case -DLM_ERRNO_EOPNOTSUPP: + return -EOPNOTSUPP; + case -DLM_ERRNO_ETIMEDOUT: + return -ETIMEDOUT; + case -DLM_ERRNO_EINPROGRESS: + return -EINPROGRESS; + } + return err; +} -- cgit v1.3.1