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/xdr.h | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 fs/nfsd/xdr.h (limited to 'fs/nfsd/xdr.h') diff --git a/fs/nfsd/xdr.h b/fs/nfsd/xdr.h new file mode 100644 index 000000000..852f71580 --- /dev/null +++ b/fs/nfsd/xdr.h @@ -0,0 +1,177 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* XDR types for nfsd. This is mainly a typing exercise. */ + +#ifndef LINUX_NFSD_H +#define LINUX_NFSD_H + +#include +#include "nfsd.h" +#include "nfsfh.h" + +struct nfsd_fhandle { + struct svc_fh fh; +}; + +struct nfsd_sattrargs { + struct svc_fh fh; + struct iattr attrs; +}; + +struct nfsd_diropargs { + struct svc_fh fh; + char * name; + unsigned int len; +}; + +struct nfsd_readargs { + struct svc_fh fh; + __u32 offset; + __u32 count; +}; + +struct nfsd_writeargs { + svc_fh fh; + __u32 offset; + __u32 len; + struct xdr_buf payload; +}; + +struct nfsd_createargs { + struct svc_fh fh; + char * name; + unsigned int len; + struct iattr attrs; +}; + +struct nfsd_renameargs { + struct svc_fh ffh; + char * fname; + unsigned int flen; + struct svc_fh tfh; + char * tname; + unsigned int tlen; +}; + +struct nfsd_linkargs { + struct svc_fh ffh; + struct svc_fh tfh; + char * tname; + unsigned int tlen; +}; + +struct nfsd_symlinkargs { + struct svc_fh ffh; + char * fname; + unsigned int flen; + char * tname; + unsigned int tlen; + struct iattr attrs; + struct kvec first; +}; + +struct nfsd_readdirargs { + struct svc_fh fh; + __u32 cookie; + __u32 count; +}; + +struct nfsd_stat { + __be32 status; +}; + +struct nfsd_attrstat { + __be32 status; + struct svc_fh fh; + struct kstat stat; +}; + +struct nfsd_diropres { + __be32 status; + struct svc_fh fh; + struct kstat stat; +}; + +struct nfsd_readlinkres { + __be32 status; + int len; + struct page *page; +}; + +struct nfsd_readres { + __be32 status; + struct svc_fh fh; + unsigned long count; + struct kstat stat; + struct page **pages; +}; + +struct nfsd_readdirres { + /* Components of the reply */ + __be32 status; + + int count; + + /* Used to encode the reply's entry list */ + struct xdr_stream xdr; + struct xdr_buf dirlist; + struct readdir_cd common; + unsigned int cookie_offset; +}; + +struct nfsd_statfsres { + __be32 status; + struct kstatfs stats; +}; + +/* + * Storage requirements for XDR arguments and results. + */ +union nfsd_xdrstore { + struct nfsd_sattrargs sattr; + struct nfsd_diropargs dirop; + struct nfsd_readargs read; + struct nfsd_writeargs write; + struct nfsd_createargs create; + struct nfsd_renameargs rename; + struct nfsd_linkargs link; + struct nfsd_symlinkargs symlink; + struct nfsd_readdirargs readdir; +}; + +#define NFS2_SVC_XDRSIZE sizeof(union nfsd_xdrstore) + + +bool nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr); + +bool nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr); +bool nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr); + +void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset); +int nfssvc_encode_entry(void *data, const char *name, int namlen, + loff_t offset, u64 ino, unsigned int d_type); + +void nfssvc_release_attrstat(struct svc_rqst *rqstp); +void nfssvc_release_diropres(struct svc_rqst *rqstp); +void nfssvc_release_readres(struct svc_rqst *rqstp); + +/* Helper functions for NFSv2 ACL code */ +bool svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp); +bool svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status); +bool svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, + const struct svc_fh *fhp, const struct kstat *stat); + +#endif /* LINUX_NFSD_H */ -- cgit v1.3.1