From: David Howells Date: Thu, 2 Jul 2009 13:35:32 +0000 (+0100) Subject: NFSD: Don't hold unrefcounted creds over call to nfsd_setuser() X-Git-Tag: v2.6.30.4~68 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=172cad5201cad098f408202a7523f41039b80933;p=karo-tx-linux.git NFSD: Don't hold unrefcounted creds over call to nfsd_setuser() commit 033a666ccb842ab4134fcd0c861d5ba9f5d6bf3a upstream. nfsd_open() gets an unrefcounted pointer to the current process's effective credentials at the top of the function, then calls nfsd_setuser() via fh_verify() - which may replace and destroy the current process's effective credentials - and then passes the unrefcounted pointer to dentry_open() - but the credentials may have been destroyed by this point. Instead, the value from current_cred() should be passed directly to dentry_open() as one of its arguments, rather than being cached in a variable. Possibly fh_verify() should return the creds to use. This is a regression introduced by 745ca2475a6ac596e3d8d37c2759c0fbe2586227 "CRED: Pass credentials through dentry_open()". Signed-off-by: David Howells Tested-and-Verified-By: Steve Dickson Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index b660435978d2..784375514411 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -677,7 +677,6 @@ __be32 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access, struct file **filp) { - const struct cred *cred = current_cred(); struct dentry *dentry; struct inode *inode; int flags = O_RDONLY|O_LARGEFILE; @@ -732,7 +731,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, vfs_dq_init(inode); } *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), - flags, cred); + flags, current_cred()); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); out_nfserr: