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 --- sound/last.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 sound/last.c (limited to 'sound/last.c') diff --git a/sound/last.c b/sound/last.c new file mode 100644 index 000000000..f0bb98780 --- /dev/null +++ b/sound/last.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Advanced Linux Sound Architecture + * Copyright (c) by Jaroslav Kysela + */ + +#include +#include + +static int __init alsa_sound_last_init(void) +{ + struct snd_card *card; + int idx, ok = 0; + + printk(KERN_INFO "ALSA device list:\n"); + for (idx = 0; idx < SNDRV_CARDS; idx++) { + card = snd_card_ref(idx); + if (card) { + printk(KERN_INFO " #%i: %s\n", idx, card->longname); + snd_card_unref(card); + ok++; + } + } + if (ok == 0) + printk(KERN_INFO " No soundcards found.\n"); + return 0; +} + +late_initcall_sync(alsa_sound_last_init); -- cgit v1.3.1