You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

Eric Paris c727709092 security: shmem: implement kernel private shmem inodes ... We have a problem where the big_key key storage implementation uses a shmem backed inode to hold the key contents. Because of this detail of implementation LSM checks are being done between processes trying to read the keys and the tmpfs backed inode. The LSM checks are already being handled on the key interface level and should not be enforced at the inode level (since the inode is an implementation detail, not a part of the security model) This patch implements a new function shmem_kernel_file_setup() which returns the equivalent to shmem_file_setup() only the underlying inode has S_PRIVATE set. This means that all LSM checks for the inode in question are skipped. It should only be used for kernel internal operations where the inode is not exposed to userspace without proper LSM checking. It is possible that some other users of shmem_file_setup() should use the new interface, but this has not been explored. Reproducing this bug is a little bit difficult. The steps I used on Fedora are: (1) Turn off selinux enforcing: setenforce 0 (2) Create a huge key k=`dd if=/dev/zero bs=8192 count=1 | keyctl padd big_key test-key @s` (3) Access the key in another context: runcon system_u:system_r:httpd_t:s0-s0:c0.c1023 keyctl print $k >/dev/null (4) Examine the audit logs: ausearch -m AVC -i --subject httpd_t | audit2allow If the last command's output includes a line that looks like: allow httpd_t user_tmpfs_t:file { open read }; There was an inode check between httpd and the tmpfs filesystem. With this patch no such denial will be seen. (NOTE! you should clear your audit log if you have tested for this previously) (Please return you box to enforcing) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Hugh Dickins <hughd@google.com> cc: linux-mm@kvack.org		11 years ago
..
encrypted-keys	…
Kconfig	KEYS: Make BIG_KEYS boolean	11 years ago
Makefile	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	12 years ago
big_key.c	security: shmem: implement kernel private shmem inodes	11 years ago
compat.c	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	12 years ago
gc.c	KEYS: Fix keyring content gc scanner	11 years ago
internal.h	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	12 years ago
key.c	KEYS: Pre-clear struct key on allocation	11 years ago
keyctl.c	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	12 years ago
keyring.c	KEYS: Fix searching of nested keyrings	11 years ago
permission.c	…
persistent.c	KEYS: Fix UID check in keyctl_get_persistent()	11 years ago
proc.c	KEYS: Introduce a search context structure	12 years ago
process_keys.c	KEYS: initialize root uid and session keyrings early	12 years ago
request_key.c	KEYS: Fix a race between negating a key and reading the error set	11 years ago
request_key_auth.c	KEYS: Search for auth-key by name rather than target key ID	12 years ago
sysctl.c	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	12 years ago
trusted.c	…
trusted.h	…
user_defined.c	KEYS: Introduce a search context structure	12 years ago