5e41ff9e06
The following patch set enables atomic security labeling of newly created inodes by altering the fs code to invoke a new LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state during the inode creation transaction. This parallels the existing processing for setting ACLs on newly created inodes. Otherwise, it is possible for new inodes to be accessed by another thread via the dcache prior to complete security setup (presently handled by the post_create/mkdir/... LSM hooks in the VFS) and a newly created inode may be left unlabeled on the disk in the event of a crash. SELinux presently works around the issue by ensuring that the incore inode security label is initialized to a special SID that is inaccessible to unprivileged processes (in accordance with policy), thereby preventing inappropriate access but potentially causing false denials on legitimate accesses. A simple test program demonstrates such false denials on SELinux, and the patch solves the problem. Similar such false denials have been encountered in real applications. This patch defines a new inode_init_security LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state for it, and adds a corresponding hook function implementation to SELinux. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
||
|---|---|---|
| .. | ||
| include | ||
| ss | ||
| avc.c | ||
| hooks.c | ||
| Kconfig | ||
| Makefile | ||
| netif.c | ||
| netlink.c | ||
| nlmsgtab.c | ||
| selinuxfs.c | ||