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| author | J. Bruce Fields <bfields@redhat.com> | 2014-08-20 14:49:50 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2014-09-08 12:02:03 -0400 |
| commit | aee3776441461c14ba6d8ed9e2149933e65abb6e (patch) | |
| tree | 3af702f6040859ed2e389218f2860407b3a3373b | |
| parent | 7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9 (diff) | |
| download | kgraft-aee3776441461c14ba6d8ed9e2149933e65abb6e.tar.gz | |
nfsd4: fix rd_dircount enforcement
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.
Cc: stable@vger.kernel.org
Fixes: 3b299709091b "nfsd4: enforce rd_dircount"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index f9821ce6658a4b..e94457c33ad630 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2657,6 +2657,7 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen, 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; @@ -2718,7 +2719,14 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen, 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; @@ -3321,6 +3329,10 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 } 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; |