6.10-stable review patch. If anyone has any objections, please let me know.
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From: Chuck Lever chuck.lever@oracle.com
commit abc02e5602f7bf9bbae1e8999570a2ad5114578c upstream.
I noticed LAYOUTGET(LAYOUTIOMODE4_RW) returning NFS4ERR_ACCESS unexpectedly. The NFS client had created a file with mode 0444, and the server had returned a write delegation on the OPEN(CREATE). The client was requesting a RW layout using the write delegation stateid so that it could flush file modifications.
Creating a read-only file does not seem to be problematic for NFSv4.1 without pNFS, so I began looking at NFSD's implementation of LAYOUTGET.
The failure was because fh_verify() was doing a permission check as part of verifying the FH presented during the LAYOUTGET. It uses the loga_iomode value to specify the @accmode argument to fh_verify(). fh_verify(MAY_WRITE) on a file whose mode is 0444 fails with -EACCES.
To permit LAYOUT* operations in this case, add OWNER_OVERRIDE when checking the access permission of the incoming file handle for LAYOUTGET and LAYOUTCOMMIT.
Cc: Christoph Hellwig hch@lst.de Cc: stable@vger.kernel.org # v6.6+ Message-Id: 4E9C0D74-A06D-4DC3-A48A-73034DC40395@oracle.com Reviewed-by: Jeff Layton jlayton@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfsd/nfs4proc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2269,7 +2269,7 @@ nfsd4_layoutget(struct svc_rqst *rqstp, const struct nfsd4_layout_ops *ops; struct nfs4_layout_stateid *ls; __be32 nfserr; - int accmode = NFSD_MAY_READ_IF_EXEC; + int accmode = NFSD_MAY_READ_IF_EXEC | NFSD_MAY_OWNER_OVERRIDE;
switch (lgp->lg_seg.iomode) { case IOMODE_READ: @@ -2359,7 +2359,8 @@ nfsd4_layoutcommit(struct svc_rqst *rqst struct nfs4_layout_stateid *ls; __be32 nfserr;
- nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_WRITE); + nfserr = fh_verify(rqstp, current_fh, 0, + NFSD_MAY_WRITE | NFSD_MAY_OWNER_OVERRIDE); if (nfserr) goto out;