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/adfs/dir_fplus.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 fs/adfs/dir_fplus.h (limited to 'fs/adfs/dir_fplus.h') diff --git a/fs/adfs/dir_fplus.h b/fs/adfs/dir_fplus.h new file mode 100644 index 000000000..d729b1591 --- /dev/null +++ b/fs/adfs/dir_fplus.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/fs/adfs/dir_fplus.h + * + * Copyright (C) 1999 Russell King + * + * Structures of directories on the F+ format disk + */ + +#define ADFS_FPLUS_NAME_LEN 255 + +#define BIGDIRSTARTNAME ('S' | 'B' << 8 | 'P' << 16 | 'r' << 24) +#define BIGDIRENDNAME ('o' | 'v' << 8 | 'e' << 16 | 'n' << 24) + +struct adfs_bigdirheader { + __u8 startmasseq; + __u8 bigdirversion[3]; + __le32 bigdirstartname; + __le32 bigdirnamelen; + __le32 bigdirsize; + __le32 bigdirentries; + __le32 bigdirnamesize; + __le32 bigdirparent; + char bigdirname[1]; +} __attribute__((packed, aligned(4))); + +struct adfs_bigdirentry { + __le32 bigdirload; + __le32 bigdirexec; + __le32 bigdirlen; + __le32 bigdirindaddr; + __le32 bigdirattr; + __le32 bigdirobnamelen; + __le32 bigdirobnameptr; +} __attribute__((packed, aligned(4))); + +struct adfs_bigdirtail { + __le32 bigdirendname; + __u8 bigdirendmasseq; + __u8 reserved[2]; + __u8 bigdircheckbyte; +} __attribute__((packed, aligned(4))); -- cgit v1.3.1