According to RFC5661, 18.36.3,
"if the client selects a value for ca_maxresponsesize such that
a replier on a channel could never send a response,the server
SHOULD return NFS4ERR_TOOSMALL in the CREATE_SESSION reply."
This patch let server error out when client sets maxreq_sz less than
SEQUENCE request size, and maxresp_sz less than a SEQUENCE reply size.
v3:
use constant for min request size and min response size,
add two function for channel attrs checking(back channel checking
not be implement),
move size check from xdr create_session to nfsd4_create_session,
Signed-off-by: Mi Jinlong <mijinlong@xxxxxxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 33 +++++++++++++++++++++++++++++++++
1 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e98f3c2..e30bf37 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1507,6 +1507,34 @@ nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses,
return slot->sl_status;
}
+#define NFSD_MIN_REQ_HDR_SEQ_SZ ((\
+ 2 * 2 + /* credential,verifier: AUTH_NULL, length 0 */ \
+ 1 + /* MIN tag is length with zero, only length */ \
+ 3 + /* version, opcount, opcode */ \
+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+ /* seqid, slotID, slotID, cache */ \
+ 4 ) * sizeof(__be32))
+
+#define NFSD_MIN_RESP_HDR_SEQ_SZ ((\
+ 2 + /* verifier: AUTH_NULL, length 0 */\
+ 1 + /* status */ \
+ 1 + /* MIN tag is length with zero, only length */ \
+ 3 + /* opcount, opcode, opstatus*/ \
+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+ /* seqid, slotID, slotID, slotID, status */ \
+ 5 ) * sizeof(__be32))
+
+static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs fchannel)
+{
+ return fchannel.maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ
+ || fchannel.maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ;
+}
+
+static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs bchannel)
+{
+ return 0;
+}
+
__be32
nfsd4_create_session(struct svc_rqst *rqstp,
struct nfsd4_compound_state *cstate,
@@ -1575,6 +1603,11 @@ nfsd4_create_session(struct svc_rqst *rqstp,
cr_ses->flags &= ~SESSION4_PERSIST;
cr_ses->flags &= ~SESSION4_RDMA;
+ status = nfserr_toosmall;
+ if (check_forechannel_attrs(cr_ses->fore_channel)
+ || check_backchannel_attrs(cr_ses->back_channel))
+ goto out;
+
status = nfserr_jukebox;
new = alloc_init_session(rqstp, conf, cr_ses);
if (!new)
--
1.7.5.4
--
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