NFSv4: Sanity check the parameters in nfs41_update_target_slotid()

Ensure that the values supplied by the server do not exceed the size of
the largest allowed slot table.

Reported-by: <rtm@csail.mit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
index 4145a01..5db4604 100644 (file)
--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -511,12 +511,16 @@ void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
                struct nfs4_slot *slot,
                struct nfs4_sequence_res *res)
 {
+       u32 target_highest_slotid = min(res->sr_target_highest_slotid,
+                                       NFS4_MAX_SLOTID);
+       u32 highest_slotid = min(res->sr_highest_slotid, NFS4_MAX_SLOTID);
+
        spin_lock(&tbl->slot_tbl_lock);
-       if (!nfs41_is_outlier_target_slotid(tbl, res->sr_target_highest_slotid))
-               nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
+       if (!nfs41_is_outlier_target_slotid(tbl, target_highest_slotid))
+               nfs41_set_target_slotid_locked(tbl, target_highest_slotid);
        if (tbl->generation == slot->generation)
-               nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
-       nfs41_set_max_slotid_locked(tbl, res->sr_target_highest_slotid);
+               nfs41_set_server_slotid_locked(tbl, highest_slotid);
+       nfs41_set_max_slotid_locked(tbl, target_highest_slotid);
        spin_unlock(&tbl->slot_tbl_lock);
 }
 

diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h
index 3de425f..351616c 100644 (file)
--- a/fs/nfs/nfs4session.h
+++ b/fs/nfs/nfs4session.h
@@ -12,6 +12,7 @@
 #define NFS4_DEF_SLOT_TABLE_SIZE (64U)
 #define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
 #define NFS4_MAX_SLOT_TABLE (1024U)
+#define NFS4_MAX_SLOTID (NFS4_MAX_SLOT_TABLE - 1U)
 #define NFS4_NO_SLOT ((u32)-1)
 
 #if IS_ENABLED(CONFIG_NFS_V4)