kernel/linux.git/net/sunrpc/xdr.c, branch v6.18.41

SUNRPC: Bound-check xdr_buf_to_bvec() stores before writing

2026-07-24T14:16:59+00:00

commit 42f5b80dda6b86e424054baf1475df686c403d5c upstream. xdr_buf_to_bvec() writes a bio_vec into the caller's array before testing whether that slot is in range, and the head branch performs the store with no check at all. When the caller's budget is exactly used up, the next store lands one element past the end of the array. The overflow label returns count - 1, which masks the surplus store but cannot undo it. rq_bvec, the array passed by nfsd_vfs_write(), is allocated to exactly rq_maxpages entries with no slack. The OOB store can land in adjacent slab memory; the bv_len and bv_offset fields written there are derived from client-supplied RPC payload sizes. Move the in-range check ahead of the store in the head, page-loop, and tail branches. With the check at the top of each sequence, count is incremented only after a successful store, so the overflow label can return count directly. Reported-by: Chris Mason Fixes: 2eb2b9358181 ("SUNRPC: Convert svc_tcp_sendmsg to use bio_vecs directly") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

Merge tag 'nfs-for-6.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2025-08-09T04:20:44+00:00

Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - don't inherit NFS filesystem capabilities when crossing from one filesystem to another Bugfixes: - NFS wakeup of __nfs_lookup_revalidate() needs memory barriers - NFS improve bounds checking in nfs_fh_to_dentry() - NFS Fix allocation errors when writing to a NFS file backed loopback device - NFSv4: More listxattr fixes - SUNRPC: fix client handling of TLS alerts - pNFS block/scsi layout fix for an uninitialised pointer dereference - pNFS block/scsi layout fixes for the extent encoding, stripe mapping, and disk offset overflows - pNFS layoutcommit work around for RPC size limitations - pNFS/flexfiles avoid looping when handling fatal errors after layoutget - localio: fix various race conditions Features and cleanups: - Add NFSv4 support for retrieving the btime - NFS: Allow folio migration for the case of mode == MIGRATE_SYNC - NFS: Support using a kernel keyring to store TLS certificates - NFSv4: Speed up delegation lookup using a hash table - Assorted cleanups to remove unused variables and struct fields - Assorted new tracepoints to improve debugging" * tag 'nfs-for-6.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (44 commits) NFS/localio: nfs_uuid_put() fix the wake up after unlinking the file NFS/localio: nfs_uuid_put() fix races with nfs_open/close_local_fh() NFS/localio: nfs_close_local_fh() fix check for file closed NFSv4: Remove duplicate lookups, capability probes and fsinfo calls NFS: Fix the setting of capabilities when automounting a new filesystem sunrpc: fix client side handling of tls alerts nfs/localio: use read_seqbegin() rather than read_seqbegin_or_lock() NFS: Fixup allocation flags for nfsiod's __GFP_NORETRY NFSv4.2: another fix for listxattr NFS: Fix filehandle bounds checking in nfs_fh_to_dentry() SUNRPC: Silence warnings about parameters not being described NFS: Clean up pnfs_put_layout_hdr()/pnfs_destroy_layout_final() NFS: Fix wakeup of __nfs_lookup_revalidate() in unblock_revalidate() NFS: use a hash table for delegation lookup NFS: track active delegations per-server NFS: move the delegation_watermark module parameter NFS: cleanup nfs_inode_reclaim_delegation NFS: cleanup error handling in nfs4_server_common_setup pNFS/flexfiles: don't attempt pnfs on fatal DS errors NFS: drop __exit from nfs_exit_keyring ...

SUNRPC: Remove unused xdr functions

2025-07-14T22:20:28+00:00

Remove a bunch of unused xdr_*decode* functions: The last use of xdr_decode_netobj() was removed in 2021 by: commit 7cf96b6d0104 ("lockd: Update the NLMv4 SHARE arguments decoder to use struct xdr_stream") The last use of xdr_decode_string_inplace() was removed in 2021 by: commit 3049e974a7c7 ("lockd: Update the NLMv4 FREE_ALL arguments decoder to use struct xdr_stream") The last use of xdr_stream_decode_opaque() was removed in 2024 by: commit fed8a17c61ff ("xdrgen: typedefs should use the built-in string and opaque functions") The functions xdr_stream_decode_string() and xdr_stream_decode_opaque_dup() were both added in 2018 by the commit 0e779aa70308 ("SUNRPC: Add helpers for decoding opaque and string types") but never used. Remove them. Signed-off-by: Dr. David Alan Gilbert Link: https://lore.kernel.org/r/20250712233006.403226-1-linux@treblig.org Signed-off-by: Trond Myklebust

sunrpc: simplify xdr_init_encode_pages

2025-07-14T16:46:37+00:00

The rqst argument to xdr_init_encode_pages is set to NULL by all callers, and pages is always set to buf->pages. Remove the two arguments and hardcode the assignments. Signed-off-by: Christoph Hellwig Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

SUNRPC: Export xdr_buf_to_bvec()

2025-05-15T20:16:24+00:00

Prepare xdr_buf_to_bvec() to be invoked from upper layer protocol code. Signed-off-by: Chuck Lever

SUNRPC: Document validity guarantees of the pointer returned by reserve_space

2025-01-11T04:43:44+00:00

A subtlety of this API is that if the @nbytes region traverses a page boundary, the next __xdr_commit_encode will shift the data item in the XDR encode buffer. This makes the returned pointer point to something else, leading to unexpected behavior. There are a few cases where the caller saves the returned pointer and then later uses it to insert a computed value into an earlier part of the stream. This can be safe only if either: - the data item is guaranteed to be in the XDR buffer's head, and thus is not ever going to be near a page boundary, or - the data item is no larger than 4 octets, since XDR alignment rules require all data items to start on 4-octet boundaries But that safety is only an artifact of the current implementation. It would be less brittle if these "safe" uses were eventually replaced. Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2023-08-31T22:36:41+00:00

Pull NFS client updates from Anna Schumaker: "New Features: - Enable the NFS v4.2 READ_PLUS operation by default Stable Fixes: - NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info - NFS: Fix a potential data corruption Bugfixes: - Fix various READ_PLUS issues including: - smatch warnings - xdr size calculations - scratch buffer handling - 32bit / highmem xdr page handling - Fix checkpatch errors in file.c - Fix redundant readdir request after an EOF - Fix handling of COPY ERR_OFFLOAD_NO_REQ - Fix assignment of xprtdata.cred Cleanups: - Remove unused xprtrdma function declarations - Clean up an integer overflow check to avoid a warning - Clean up #includes in dns_resolve.c - Clean up nfs4_get_device_info so we don't pass a NULL pointer to __free_page() - Clean up sunrpc TCP socket timeout configuration - Guard against READDIR loops when entry names are too long - Use EXCHID4_FLAG_USE_PNFS_DS for DS servers" * tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (22 commits) pNFS: Fix assignment of xprtdata.cred NFSv4.2: fix handling of COPY ERR_OFFLOAD_NO_REQ NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt() SUNRPC: Allow specification of TCP client connect timeout at setup SUNRPC: Refactor and simplify connect timeout SUNRPC: Set the TCP_SYNCNT to match the socket timeout NFS: Fix a potential data corruption nfs: fix redundant readdir request after get eof nfs/blocklayout: Use the passed in gfp flags filemap: Fix errors in file.c NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info NFS: Move common includes outside ifdef SUNRPC: clean up integer overflow check xprtrdma: Remove unused function declaration rpcrdma_bc_post_recv() NFS: Enable the READ_PLUS operation by default SUNRPC: kmap() the xdr pages during decode NFSv4.2: Rework scratch handling for READ_PLUS (again) ...

SUNRPC: Convert svc_tcp_sendmsg to use bio_vecs directly

2023-08-29T21:45:22+00:00

Add a helper to convert a whole xdr_buf directly into an array of bio_vecs, then send this array instead of iterating piecemeal over the xdr_buf containing the outbound RPC message. Reviewed-by: David Howells Signed-off-by: Chuck Lever

SUNRPC: kmap() the xdr pages during decode

2023-08-23T19:58:47+00:00

If the pages are in HIGHMEM then we need to make sure they're mapped before trying to read data off of them, otherwise we could end up with a NULL pointer dereference. The downside to this is that we need an extra cleanup step at the end of decode to kunmap() the last page. I introduced an xdr_finish_decode() function to do this. Right now this function only calls the unmap_current_page() function, but other generic cleanup steps could be added in the future if we come across anything else. Reported-by: Krzysztof Kozlowski Signed-off-by: Anna Schumaker

NFSD: Hoist rq_vec preparation into nfsd_read() [step two]

2023-06-11T20:37:46+00:00

Now that the preparation of an rq_vec has been removed from the generic read path, nfsd_splice_read() no longer needs to reset rq_next_page. nfsd4_encode_read() calls nfsd_splice_read() directly. As far as I can ascertain, resetting rq_next_page for NFSv4 splice reads is unnecessary because rq_next_page is already set correctly. Moreover, resetting it might even be incorrect if previous operations in the COMPOUND have already consumed at least a page of the send buffer. I would expect that the result would be encoding the READ payload over previously-encoded results. Signed-off-by: Chuck Lever