| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.16 155/357] nfsd4: fix rd_dircount enforcement | Date | Fri, 3 Oct 2014 14:29:01 -0700 |
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3.16-stable review patch. If anyone has any objections, please let me know.
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From: "J. Bruce Fields" <bfields@redhat.com>
commit aee3776441461c14ba6d8ed9e2149933e65abb6e upstream.
Commit 3b299709091b "nfsd4: enforce rd_dircount" totally misunderstood rd_dircount; it refers to total non-attribute bytes returned, not number of directory entries returned.
Bring the code into agreement with RFC 3530 section 14.2.24.
Fixes: 3b299709091b "nfsd4: enforce rd_dircount" Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/nfsd/nfs4xdr.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
--- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2662,6 +2662,7 @@ nfsd4_encode_dirent(void *ccdv, const ch struct xdr_stream *xdr = cd->xdr; int start_offset = xdr->buf->len; int cookie_offset; + u32 name_and_cookie; int entry_bytes; __be32 nfserr = nfserr_toosmall; __be64 wire_offset; @@ -2723,7 +2724,14 @@ nfsd4_encode_dirent(void *ccdv, const ch cd->rd_maxcount -= entry_bytes; if (!cd->rd_dircount) goto fail; - cd->rd_dircount--; + /* + * RFC 3530 14.2.24 describes rd_dircount as only a "hint", so + * let's always let through the first entry, at least: + */ + name_and_cookie = 4 * XDR_QUADLEN(namlen) + 8; + if (name_and_cookie > cd->rd_dircount && cd->cookie_offset) + goto fail; + cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie); cd->cookie_offset = cookie_offset; skip_entry: cd->common.err = nfs_ok; @@ -3333,6 +3341,10 @@ nfsd4_encode_readdir(struct nfsd4_compou } maxcount = min_t(int, maxcount-16, bytes_left); + /* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */ + if (!readdir->rd_dircount) + readdir->rd_dircount = INT_MAX; + readdir->xdr = xdr; readdir->rd_maxcount = maxcount; readdir->common.err = 0;
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