linux/security/security.c, branch v2.6.38

security: add cred argument to security_capable()

2011-02-11T06:41:58Z

Expand security_capable() to include cred, so that it can be usable in a wider range of call sites. Signed-off-by: Chris Wright Acked-by: Serge Hallyn Signed-off-by: James Morris

Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

2011-01-07T16:56:33Z

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits) fs: scale mntget/mntput fs: rename vfsmount counter helpers fs: implement faster dentry memcmp fs: prefetch inode data in dcache lookup fs: improve scalability of pseudo filesystems fs: dcache per-inode inode alias locking fs: dcache per-bucket dcache hash locking bit_spinlock: add required includes kernel: add bl_list xfs: provide simple rcu-walk ACL implementation btrfs: provide simple rcu-walk ACL implementation ext2,3,4: provide simple rcu-walk ACL implementation fs: provide simple rcu-walk generic_check_acl implementation fs: provide rcu-walk aware permission i_ops fs: rcu-walk aware d_revalidate method fs: cache optimise dentry and inode for rcu-walk fs: dcache reduce branches in lookup path fs: dcache remove d_mounted fs: fs_struct use seqlock fs: rcu-walk for path lookup ...

fs: rcu-walk for path lookup

2011-01-07T06:50:27Z

Perform common cases of path lookups without any stores or locking in the ancestor dentry elements. This is called rcu-walk, as opposed to the current algorithm which is a refcount based walk, or ref-walk. This results in far fewer atomic operations on every path element, significantly improving path lookup performance. It also avoids cacheline bouncing on common dentries, significantly improving scalability. The overall design is like this: * LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk. * Take the RCU lock for the entire path walk, starting with the acquiring of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are not required for dentry persistence. * synchronize_rcu is called when unregistering a filesystem, so we can access d_ops and i_ops during rcu-walk. * Similarly take the vfsmount lock for the entire path walk. So now mnt refcounts are not required for persistence. Also we are free to perform mount lookups, and to assume dentry mount points and mount roots are stable up and down the path. * Have a per-dentry seqlock to protect the dentry name, parent, and inode, so we can load this tuple atomically, and also check whether any of its members have changed. * Dentry lookups (based on parent, candidate string tuple) recheck the parent sequence after the child is found in case anything changed in the parent during the path walk. * inode is also RCU protected so we can load d_inode and use the inode for limited things. * i_mode, i_uid, i_gid can be tested for exec permissions during path walk. * i_op can be loaded. When we reach the destination dentry, we lock it, recheck lookup sequence, and increment its refcount and mountpoint refcount. RCU and vfsmount locks are dropped. This is termed "dropping rcu-walk". If the dentry refcount does not match, we can not drop rcu-walk gracefully at the current point in the lokup, so instead return -ECHILD (for want of a better errno). This signals the path walking code to re-do the entire lookup with a ref-walk. Aside from the final dentry, there are other situations that may be encounted where we cannot continue rcu-walk. In that case, we drop rcu-walk (ie. take a reference on the last good dentry) and continue with a ref-walk. Again, if we can drop rcu-walk gracefully, we return -ECHILD and do the whole lookup using ref-walk. But it is very important that we can continue with ref-walk for most cases, particularly to avoid the overhead of double lookups, and to gain the scalability advantages on common path elements (like cwd and root). The cases where rcu-walk cannot continue are: * NULL dentry (ie. any uncached path element) * parent with d_inode->i_op->permission or ACLs * dentries with d_revalidate * Following links In future patches, permission checks and d_revalidate become rcu-walk aware. It may be possible eventually to make following links rcu-walk aware. Uncached path elements will always require dropping to ref-walk mode, at the very least because i_mutex needs to be grabbed, and objects allocated. Signed-off-by: Nick Piggin

af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.

2011-01-05T23:38:53Z

unix_release() can asynchornously set socket->sk to NULL, and it does so without holding the unix_state_lock() on "other" during stream connects. However, the reverse mapping, sk->sk_socket, is only transitioned to NULL under the unix_state_lock(). Therefore make the security hooks follow the reverse mapping instead of the forward mapping. Reported-by: Jeremy Fitzhardinge Reported-by: Linus Torvalds Signed-off-by: David S. Miller

capabilities/syslog: open code cap_syslog logic to fix build failure

2010-11-15T23:40:01Z

The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build failure when CONFIG_PRINTK=n. This is because the capabilities code which used the new option was built even though the variable in question didn't exist. The patch here fixes this by moving the capabilities checks out of the LSM and into the caller. All (known) LSMs should have been calling the capabilities hook already so it actually makes the code organization better to eliminate the hook altogether. Signed-off-by: Eric Paris Acked-by: James Morris Signed-off-by: Linus Torvalds

Merge branch 'ima-memory-use-fixes'

2010-10-26T18:37:48Z

* ima-memory-use-fixes: IMA: fix the ToMToU logic IMA: explicit IMA i_flag to remove global lock on inode_delete IMA: drop refcnt from ima_iint_cache since it isn't needed IMA: only allocate iint when needed IMA: move read counter into struct inode IMA: use i_writecount rather than a private counter IMA: use inode->i_lock to protect read and write counters IMA: convert internal flags from long to char IMA: use unsigned int instead of long for counters IMA: drop the inode opencount since it isn't needed for operation IMA: use rbtree instead of radix tree for inode information cache

IMA: only allocate iint when needed

2010-10-26T18:37:18Z

IMA always allocates an integrity structure to hold information about every inode, but only needed this structure to track the number of readers and writers currently accessing a given inode. Since that information was moved into struct inode instead of the integrity struct this patch stops allocating the integrity stucture until it is needed. Thus greatly reducing memory usage. Signed-off-by: Eric Paris Acked-by: Mimi Zohar Signed-off-by: Linus Torvalds

secmark: make secmark object handling generic

2010-10-20T23:12:48Z

Right now secmark has lots of direct selinux calls. Use all LSM calls and remove all SELinux specific knowledge. The only SELinux specific knowledge we leave is the mode. The only point is to make sure that other LSMs at least test this generic code before they assume it works. (They may also have to make changes if they do not represent labels as strings) Signed-off-by: Eric Paris Acked-by: Paul Moore Acked-by: Patrick McHardy Signed-off-by: James Morris

security: remove unused parameter from security_task_setscheduler()

2010-10-20T23:12:44Z

All security modules shouldn't change sched_param parameter of security_task_setscheduler(). This is not only meaningless, but also make a harmful result if caller pass a static variable. This patch remove policy and sched_param parameter from security_task_setscheduler() becuase none of security module is using it. Cc: James Morris Signed-off-by: KOSAKI Motohiro Signed-off-by: James Morris

LSM: Fix security_module_enable() error.

2010-10-20T23:12:34Z

We can set default LSM module to DAC (which means "enable no LSM module"). If default LSM module was set to DAC, security_module_enable() must return 0 unless overridden via boot time parameter. Signed-off-by: Tetsuo Handa Acked-by: Serge E. Hallyn Signed-off-by: James Morris