nfsd4: enforce rd_dircount

As long as we're here, let's enforce the protocol's limit on the number
of directory entries to return in a readdir.

I don't think anyone's ever noticed our lack of enforcement, but maybe
there's more of a chance they will now that we allow larger readdirs.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2014-03-20 21:20:26 -04:00
parent 561f0ed498
commit 3b29970909

View File

@ -1033,7 +1033,7 @@ nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *read
READ_BUF(24);
READ64(readdir->rd_cookie);
COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
READ32(readdir->rd_dircount); /* just in case you needed a useless field... */
READ32(readdir->rd_dircount);
READ32(readdir->rd_maxcount);
if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
goto out;
@ -2720,6 +2720,9 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
if (entry_bytes > cd->rd_maxcount)
goto fail;
cd->rd_maxcount -= entry_bytes;
if (!cd->rd_dircount)
goto fail;
cd->rd_dircount--;
cd->cookie_offset = cookie_offset;
skip_entry:
cd->common.err = nfs_ok;