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/nfsd/blocklayoutxdr.h | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 fs/nfsd/blocklayoutxdr.h (limited to 'fs/nfsd/blocklayoutxdr.h') diff --git a/fs/nfsd/blocklayoutxdr.h b/fs/nfsd/blocklayoutxdr.h new file mode 100644 index 000000000..2e0c6c7d2 --- /dev/null +++ b/fs/nfsd/blocklayoutxdr.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NFSD_BLOCKLAYOUTXDR_H +#define _NFSD_BLOCKLAYOUTXDR_H 1 + +#include +#include "xdr4.h" + +struct iomap; +struct xdr_stream; + +/* On the wire size of the layout4 struct with zero number of extents */ +#define PNFS_BLOCK_LAYOUT4_SIZE \ + (sizeof(__be32) * 2 + /* offset4 */ \ + sizeof(__be32) * 2 + /* length4 */ \ + sizeof(__be32) + /* layoutiomode4 */ \ + sizeof(__be32) + /* layouttype4 */ \ + sizeof(__be32) + /* number of bytes */ \ + sizeof(__be32)) /* number of extents */ + +struct pnfs_block_extent { + struct nfsd4_deviceid vol_id; + u64 foff; + u64 len; + u64 soff; + enum pnfs_block_extent_state es; +}; + +struct pnfs_block_range { + u64 foff; + u64 len; +}; + +struct pnfs_block_layout { + u32 nr_extents; + struct pnfs_block_extent extents[] __counted_by(nr_extents); +}; + +/* + * Random upper cap for the uuid length to avoid unbounded allocation. + * Not actually limited by the protocol. + */ +#define PNFS_BLOCK_UUID_LEN 128 + +struct pnfs_block_volume { + enum pnfs_block_volume_type type; + union { + struct { + u64 offset; + u32 sig_len; + u8 sig[PNFS_BLOCK_UUID_LEN]; + } simple; + struct { + enum scsi_code_set code_set; + enum scsi_designator_type designator_type; + int designator_len; + u8 designator[256]; + u64 pr_key; + } scsi; + }; +}; + +struct pnfs_block_deviceaddr { + u32 nr_volumes; + struct pnfs_block_volume volumes[] __counted_by(nr_volumes); +}; + +__be32 nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr, + const struct nfsd4_getdeviceinfo *gdp); +__be32 nfsd4_block_encode_layoutget(struct xdr_stream *xdr, + const struct nfsd4_layoutget *lgp); +__be32 nfsd4_block_decode_layoutupdate(struct xdr_stream *xdr, + struct iomap **iomapp, int *nr_iomapsp, u32 block_size); +__be32 nfsd4_scsi_decode_layoutupdate(struct xdr_stream *xdr, + struct iomap **iomapp, int *nr_iomapsp, u32 block_size); + +#endif /* _NFSD_BLOCKLAYOUTXDR_H */ -- cgit v1.3.1