4.9-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
commit fc40724fc6731d90cc7fb6d62d66135f85a33dd2 upstream.
The correct behaviour for NFSv4 sequence IDs is to wrap around to the value 0 after 0xffffffff. See https://tools.ietf.org/html/rfc5661#section-2.10.6.1
Fixes: 5f83d86cf531d ("NFSv4.x: Fix wraparound issues when validing...") Cc: stable@vger.kernel.org # 4.6+ Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/nfs/callback_proc.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
--- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -402,11 +402,8 @@ validate_seqid(const struct nfs4_slot_ta return htonl(NFS4ERR_SEQ_FALSE_RETRY); }
- /* Wraparound */ - if (unlikely(slot->seq_nr == 0xFFFFFFFFU)) { - if (args->csa_sequenceid == 1) - return htonl(NFS4_OK); - } else if (likely(args->csa_sequenceid == slot->seq_nr + 1)) + /* Note: wraparound relies on seq_nr being of type u32 */ + if (likely(args->csa_sequenceid == slot->seq_nr + 1)) return htonl(NFS4_OK);
/* Misordered request */