@@ -4955,25 +4955,49 @@ static void nfs4_init_boot_verifier(const struct nfs_client *clp,
memcpy(bootverf->data, verf, sizeof(bootverf->data));
}
-static unsigned int
-nfs4_init_nonuniform_client_string(struct nfs_client *clp,
- char *buf, size_t len)
+static int
+nfs4_init_nonuniform_client_string(struct nfs_client *clp)
{
- unsigned int result;
+ int result;
+ size_t len;
+ char *str;
+ bool retried = false;
if (clp->cl_owner_id != NULL)
- return strlcpy(buf, clp->cl_owner_id, len);
+ return 0;
+retry:
+ rcu_read_lock();
+ len = 10 + strlen(clp->cl_ipaddr) + 1 +
+ strlen(rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)) +
+ 1 +
+ strlen(rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO)) +
+ 1;
+ rcu_read_unlock();
+
+ if (len > NFS4_OPAQUE_LIMIT + 1)
+ return -EINVAL;
+
+ str = kmalloc(len, GFP_NOFS);
+ if (!str)
+ return -ENOMEM;
rcu_read_lock();
- result = scnprintf(buf, len, "Linux NFSv4.0 %s/%s %s",
- clp->cl_ipaddr,
- rpc_peeraddr2str(clp->cl_rpcclient,
- RPC_DISPLAY_ADDR),
- rpc_peeraddr2str(clp->cl_rpcclient,
- RPC_DISPLAY_PROTO));
+ result = scnprintf(str, len, "Linux NFSv4.0 %s/%s %s",
+ clp->cl_ipaddr,
+ rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
+ rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO));
rcu_read_unlock();
- clp->cl_owner_id = kstrdup(buf, GFP_NOFS);
- return result;
+
+ /* Did something change? */
+ if (result >= len) {
+ kfree(str);
+ if (retried)
+ return -EINVAL;
+ retried = true;
+ goto retry;
+ }
+ clp->cl_owner_id = str;
+ return 0;
}
static unsigned int
@@ -5064,20 +5088,19 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
/* nfs_client_id4 */
nfs4_init_boot_verifier(clp, &sc_verifier);
- if (test_bit(NFS_CS_MIGRATION, &clp->cl_flags))
+ if (test_bit(NFS_CS_MIGRATION, &clp->cl_flags)) {
setclientid.sc_name_len =
nfs4_init_uniform_client_string(clp,
setclientid.sc_name,
sizeof(setclientid.sc_name));
- else
- setclientid.sc_name_len =
- nfs4_init_nonuniform_client_string(clp,
- setclientid.sc_name,
- sizeof(setclientid.sc_name));
-
- if (!clp->cl_owner_id) {
- status = -ENOMEM;
- goto out;
+ if (!clp->cl_owner_id) {
+ status = -ENOMEM;
+ goto out;
+ }
+ } else {
+ status = nfs4_init_nonuniform_client_string(clp);
+ if (status)
+ goto out;
}
/* cb_client4 */
The way the *_client_string functions work is a little goofy. They build the string in an on-stack buffer and then use kstrdup to copy it. This is not only stack-heavy but artificially limits the size of the client name string. Change it so that we determine the length of the string, allocate it and then scnprintf into it. Since the contents of the nonuniform string depend on rcu-managed data structures, it's possible that they'll change between when we allocate the string and when we go to fill it. If that happens, free the string, recalculate the length and try again. If it the mismatch isn't resolved on the second try then just give up and return -EINVAL. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> --- fs/nfs/nfs4proc.c | 69 ++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 46 insertions(+), 23 deletions(-)