The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a648fdeb7c0e17177a2280344d015dba3fbe3314 Mon Sep 17 00:00:00 2001 From: Chuck Lever chuck.lever@oracle.com Date: Tue, 25 Jan 2022 15:59:57 -0500 Subject: [PATCH] NFSD: Fix NFSv3 SETATTR/CREATE's handling of large file sizes

iattr::ia_size is a loff_t, so these NFSv3 procedures must be careful to deal with incoming client size values that are larger than s64_max without corrupting the value.

Silently capping the value results in storing a different value than the client passed in which is unexpected behavior, so remove the min_t() check in decode_sattr3().

Note that RFC 1813 permits only the WRITE procedure to return NFS3ERR_FBIG. We believe that NFSv3 reference implementations also return NFS3ERR_FBIG when ia_size is too large.

Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 7c45ba4db61b..2e47a07029f1 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -254,7 +254,7 @@ svcxdr_decode_sattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr, if (xdr_stream_decode_u64(xdr, &newsize) < 0) return false; iap->ia_valid |= ATTR_SIZE; - iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX); + iap->ia_size = newsize; } if (xdr_stream_decode_u32(xdr, &set_it) < 0) return false;