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 --- scripts/ssl-common.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 scripts/ssl-common.h (limited to 'scripts/ssl-common.h') diff --git a/scripts/ssl-common.h b/scripts/ssl-common.h new file mode 100644 index 000000000..2db0e1811 --- /dev/null +++ b/scripts/ssl-common.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +/* + * SSL helper functions shared by sign-file and extract-cert. + */ + +static void drain_openssl_errors(int l, int silent) +{ + const char *file; + char buf[120]; + int e, line; + + if (ERR_peek_error() == 0) + return; + if (!silent) + fprintf(stderr, "At main.c:%d:\n", l); + + while ((e = ERR_peek_error_line(&file, &line))) { + ERR_error_string(e, buf); + if (!silent) + fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line); + ERR_get_error(); + } +} + +#define ERR(cond, fmt, ...) \ + do { \ + bool __cond = (cond); \ + drain_openssl_errors(__LINE__, 0); \ + if (__cond) { \ + errx(1, fmt, ## __VA_ARGS__); \ + } \ + } while (0) -- cgit v1.3.1