linux/security
Eric Paris b9593d309d IMA: use i_writecount rather than a private counter
IMA tracks the number of struct files which are holding a given inode
readonly and the number which are holding the inode write or r/w.  It
needs this information so when a new reader or writer comes in it can
tell if this new file will be able to invalidate results it already made
about existing files.

aka if a task is holding a struct file open RO, IMA measured the file
and recorded those measurements and then a task opens the file RW IMA
needs to note in the logs that the old measurement may not be correct.
It's called a "Time of Measure Time of Use" (ToMToU) issue.  The same is
true is a RO file is opened to an inode which has an open writer.  We
cannot, with any validity, measure the file in question since it could
be changing.

This patch attempts to use the i_writecount field to track writers.  The
i_writecount field actually embeds more information in it's value than
IMA needs but it should work for our purposes and allow us to shrink the
struct inode even more.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
..
apparmor AppArmor: Fix locking from removal of profile namespace 2010-09-08 09:19:34 +10:00
integrity/ima IMA: use i_writecount rather than a private counter 2010-10-26 11:37:18 -07:00
keys KEYS: Fix bug in keyctl_session_to_parent() if parent has no session keyring 2010-09-10 07:30:00 -07:00
selinux tty: fix fu_list abuse 2010-08-18 08:35:47 -04:00
smack Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-08-04 15:31:02 -07:00
tomoyo TOMOYO: Don't abuse sys_getpid(), sys_getppid() 2010-09-27 10:53:18 +10:00
capability.c Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux 2010-08-10 12:07:51 -07:00
commoncap.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
device_cgroup.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
inode.c securityfs: Drop dentry reference count when mknod fails 2010-08-02 15:34:59 +10:00
Kconfig AppArmor: Enable configuring and building of the AppArmor security module 2010-08-02 15:38:34 +10:00
lsm_audit.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
Makefile AppArmor: Enable configuring and building of the AppArmor security module 2010-08-02 15:38:34 +10:00
min_addr.c mmap_min_addr check CAP_SYS_RAWIO only for write 2010-04-23 08:56:31 +10:00
security.c Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux 2010-08-10 12:07:51 -07:00