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/ubifs/misc.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 fs/ubifs/misc.c (limited to 'fs/ubifs/misc.c') diff --git a/fs/ubifs/misc.c b/fs/ubifs/misc.c new file mode 100644 index 000000000..cd23de0f2 --- /dev/null +++ b/fs/ubifs/misc.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "ubifs.h" + +/* Normal UBIFS messages */ +void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_notice("UBIFS (ubi%d:%d): %pV\n", + c->vi.ubi_num, c->vi.vol_id, &vaf); + + va_end(args); +} \ + +/* UBIFS error messages */ +void ubifs_err(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_err("UBIFS error (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} \ + +/* UBIFS warning messages */ +void ubifs_warn(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_warn("UBIFS warning (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} + +static char *assert_names[] = { + [ASSACT_REPORT] = "report", + [ASSACT_RO] = "read-only", + [ASSACT_PANIC] = "panic", +}; + +const char *ubifs_assert_action_name(struct ubifs_info *c) +{ + return assert_names[c->assert_action]; +} -- cgit v1.3.1