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authorJ. Bruce Fields <bfields@redhat.com>2014-08-20 22:49:50 +0400
committerJ. Bruce Fields <bfields@redhat.com>2014-09-08 20:02:03 +0400
commitaee3776441461c14ba6d8ed9e2149933e65abb6e (patch)
tree3af702f6040859ed2e389218f2860407b3a3373b /fs
parent7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9 (diff)
downloadlinux-aee3776441461c14ba6d8ed9e2149933e65abb6e.tar.xz
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfs4xdr.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index f9821ce6658a..e94457c33ad6 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;