The patch titled nfsd: don't hold unrefcounted creds over call to nfsd_setuser() has been added to the -mm tree. Its filename is nfsd-dont-hold-unrefcounted-creds-over-call-to-nfsd_setuser.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: nfsd: don't hold unrefcounted creds over call to nfsd_setuser() From: David Howells <dhowells@xxxxxxxxxx> 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. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Tested-and-Verified-By: Steve Dickson <steved@xxxxxxxxxx> Cc: <rasmus@xxxxxxxxxxxx> Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx> Cc: Neil Brown <neilb@xxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/nfsd/vfs.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff -puN fs/nfsd/vfs.c~nfsd-dont-hold-unrefcounted-creds-over-call-to-nfsd_setuser fs/nfsd/vfs.c --- a/fs/nfsd/vfs.c~nfsd-dont-hold-unrefcounted-creds-over-call-to-nfsd_setuser +++ a/fs/nfsd/vfs.c @@ -678,7 +678,6 @@ __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; @@ -733,7 +732,7 @@ nfsd_open(struct svc_rqst *rqstp, struct 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); else _ Patches currently in -mm which might be from dhowells@xxxxxxxxxx are origin.patch linux-next.patch elf-fix-multithreaded-program-core-dumping-on-arm.patch flat-fix-uninitialized-ptr-with-shared-libs.patch cred_guard_mutex-do-not-return-eintr-to-user-space.patch nfsd-dont-hold-unrefcounted-creds-over-call-to-nfsd_setuser.patch frv-duplicate-output_buffer-of-e03.patch rework-fix-is_single_threaded.patch elf-clean-up-fill_note_info.patch elf-clean-up-fill_note_info-fix.patch flat-use-is_err_value-helper-macro.patch mutex-subsystem-synchro-test-module.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html