From eb96d5c97b0825d542e9c4ba5e0a22b519355166 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Tue, 27 Nov 2012 10:34:19 -0500 Subject: SUNRPC handle EKEYEXPIRED in call_refreshresult Currently, when an RPCSEC_GSS context has expired or is non-existent and the users (Kerberos) credentials have also expired or are non-existent, the client receives the -EKEYEXPIRED error and tries to refresh the context forever. If an application is performing I/O, or other work against the share, the application hangs, and the user is not prompted to refresh/establish their credentials. This can result in a denial of service for other users. Users are expected to manage their Kerberos credential lifetimes to mitigate this issue. Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number of times to refresh the gss_context, and then return -EACCES to the application. Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust --- fs/nfs/proc.c | 43 ------------------------------------------- 1 file changed, 43 deletions(-) (limited to 'fs/nfs/proc.c') diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c index 50a88c3546ed..f084dac948e1 100644 --- a/fs/nfs/proc.c +++ b/fs/nfs/proc.c @@ -46,39 +46,6 @@ #define NFSDBG_FACILITY NFSDBG_PROC -/* - * wrapper to handle the -EKEYEXPIRED error message. This should generally - * only happen if using krb5 auth and a user's TGT expires. NFSv2 doesn't - * support the NFSERR_JUKEBOX error code, but we handle this situation in the - * same way that we handle that error with NFSv3. - */ -static int -nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags) -{ - int res; - do { - res = rpc_call_sync(clnt, msg, flags); - if (res != -EKEYEXPIRED) - break; - freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME); - res = -ERESTARTSYS; - } while (!fatal_signal_pending(current)); - return res; -} - -#define rpc_call_sync(clnt, msg, flags) nfs_rpc_wrapper(clnt, msg, flags) - -static int -nfs_async_handle_expired_key(struct rpc_task *task) -{ - if (task->tk_status != -EKEYEXPIRED) - return 0; - task->tk_status = 0; - rpc_restart_call(task); - rpc_delay(task, NFS_JUKEBOX_RETRY_TIME); - return 1; -} - /* * Bare-bones access to getattr: this is for nfs_read_super. */ @@ -364,8 +331,6 @@ static void nfs_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlink static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir) { - if (nfs_async_handle_expired_key(task)) - return 0; nfs_mark_for_revalidate(dir); return 1; } @@ -385,8 +350,6 @@ static int nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir, struct inode *new_dir) { - if (nfs_async_handle_expired_key(task)) - return 0; nfs_mark_for_revalidate(old_dir); nfs_mark_for_revalidate(new_dir); return 1; @@ -642,9 +605,6 @@ static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data) { struct inode *inode = data->header->inode; - if (nfs_async_handle_expired_key(task)) - return -EAGAIN; - nfs_invalidate_atime(inode); if (task->tk_status >= 0) { nfs_refresh_inode(inode, data->res.fattr); @@ -671,9 +631,6 @@ static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data) { struct inode *inode = data->header->inode; - if (nfs_async_handle_expired_key(task)) - return -EAGAIN; - if (task->tk_status >= 0) nfs_post_op_update_inode_force_wcc(inode, data->res.fattr); return 0; -- cgit v1.2.3-70-g09d2