David Howells 0b0a84154e KEYS: request_key() should reget expired keys rather than give EKEYEXPIRED ... Since the keyring facility can be viewed as a cache (at least in some applications), the local expiration time on the key should probably be viewed as a 'needs updating after this time' property rather than an absolute 'anyone now wanting to use this object is out of luck' property. Since request_key() is the main interface for the usage of keys, this should update or replace an expired key rather than issuing EKEYEXPIRED if the local expiration has been reached (ie. it should refresh the cache). For absolute conditions where refreshing the cache probably doesn't help, the key can be negatively instantiated using KEYCTL_REJECT_KEY with EKEYEXPIRED given as the error to issue. This will still cause request_key() to return EKEYEXPIRED as that was explicitly set. In the future, if the key type has an update op available, we might want to upcall with the expired key and allow the upcall to update it. We would pass a different operation name (the first column in /etc/request-key.conf) to the request-key program. request_key() returning EKEYEXPIRED is causing an NFS problem which Chuck Lever describes thusly: After about 10 minutes, my NFSv4 functional tests fail because the ownership of the test files goes to "-2". Looking at /proc/keys shows that the id_resolv keys that map to my test user ID have expired. The ownership problem persists until the expired keys are purged from the keyring, and fresh keys are obtained. I bisected the problem to 3.13 commit b2a4df200d ("KEYS: Expand the capacity of a keyring"). This commit inadvertantly changes the API contract of the internal function keyring_search_aux(). The root cause appears to be that b2a4df200d made "no state check" the default behavior. "No state check" means the keyring search iterator function skips checking the key's expiry timeout, and returns expired keys. request_key_and_link() depends on getting an -EAGAIN result code to know when to perform an upcall to refresh an expired key. This patch can be tested directly by: keyctl request2 user debug:fred a @s keyctl timeout %user:debug:fred 3 sleep 4 keyctl request2 user debug:fred a @s Without the patch, the last command gives error EKEYEXPIRED, but with the command it gives a new key. Reported-by: Carl Hetherington <cth@carlh.net> Reported-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Chuck Lever <chuck.lever@oracle.com>		2014-12-01 22:52:53 +00:00
..
apparmor	module: rename KERNEL_PARAM_FL_NOARG to avoid confusion	2014-08-27 21:54:07 +09:30
integrity	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus	2014-10-29 15:03:54 +11:00
keys	KEYS: request_key() should reget expired keys rather than give EKEYEXPIRED	2014-12-01 22:52:53 +00:00
selinux	Merge branch 'stable-3.18' of git://git.infradead.org/users/pcmoore/selinux into for-linus	2014-11-13 21:49:53 +11:00
smack	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2014-10-12 10:13:55 -04:00
tomoyo	tomoyo: Fix pathname calculation breakage.	2014-08-26 21:52:09 -05:00
yama
capability.c	security: make security_file_set_fowner, f_setown and __f_setown void return	2014-09-09 16:01:36 -04:00
commoncap.c	CAPABILITIES: remove undefined caps from all processes	2014-07-24 21:53:47 +10:00
device_cgroup.c
inode.c	Documentation: Docbook: Fix generated DocBook/kernel-api.xml	2014-09-09 10:34:56 +02:00
Kconfig
lsm_audit.c
Makefile
min_addr.c
security.c	security: make security_file_set_fowner, f_setown and __f_setown void return	2014-09-09 16:01:36 -04:00