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/jffs2/writev.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 fs/jffs2/writev.c (limited to 'fs/jffs2/writev.c') diff --git a/fs/jffs2/writev.c b/fs/jffs2/writev.c new file mode 100644 index 000000000..a1bda9dab --- /dev/null +++ b/fs/jffs2/writev.c @@ -0,0 +1,51 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * + * Created by David Woodhouse + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include +#include +#include "nodelist.h" + +int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs, + unsigned long count, loff_t to, size_t *retlen) +{ + if (!jffs2_is_writebuffered(c)) { + if (jffs2_sum_active()) { + int res; + res = jffs2_sum_add_kvec(c, vecs, count, (uint32_t) to); + if (res) { + return res; + } + } + } + + return mtd_writev(c->mtd, vecs, count, to, retlen); +} + +int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, + size_t *retlen, const u_char *buf) +{ + int ret; + ret = mtd_write(c->mtd, ofs, len, retlen, buf); + + if (jffs2_sum_active()) { + struct kvec vecs[1]; + int res; + + vecs[0].iov_base = (unsigned char *) buf; + vecs[0].iov_len = len; + + res = jffs2_sum_add_kvec(c, vecs, 1, (uint32_t) ofs); + if (res) { + return res; + } + } + return ret; +} -- cgit v1.3.1