wireguard-linux/fs/kernfs/inode.c, branch jd/unified-crypt-queue

kernfs: Add option to enable user xattrs

2020-03-16T19:53:47Z

User extended attributes are useful as metadata storage for kernfs consumers like cgroups. Especially in the case of cgroups, it is useful to have a central metadata store that multiple processes/services can use to coordinate actions. A concrete example is for userspace out of memory killers. We want to let delegated cgroup subtree owners (running as non-root) to be able to say "please avoid killing this cgroup". This is especially important for desktop linux as delegated subtrees owners are less likely to run as root. This patch introduces a new flag, KERNFS_ROOT_SUPPORT_USER_XATTR, that lets kernfs consumers enable user xattr support. An initial limit of 128 entries or 128KB -- whichever is hit first -- is placed per cgroup because xattrs come from kernel memory and we don't want to let unprivileged users accidentally eat up too much kernel memory. Signed-off-by: Daniel Xu Acked-by: Chris Down Reviewed-by: Greg Kroah-Hartman Signed-off-by: Tejun Heo

kernfs: Add removed_size out param for simple_xattr_set

2020-03-16T19:53:47Z

This helps set up size accounting in the next commit. Without this out param, it's difficult to find out the removed xattr size without taking a lock for longer and walking the xattr linked list twice. Signed-off-by: Daniel Xu Acked-by: Chris Down Reviewed-by: Greg Kroah-Hartman Signed-off-by: Tejun Heo

kernfs: don't bother with timestamp truncation

2019-12-09T00:10:57Z

kernfs users are not going to have limited range or granularity anyway. Signed-off-by: Al Viro

kernfs: convert kernfs_node->id from union kernfs_node_id to u64

2019-11-12T16:18:03Z

kernfs_node->id is currently a union kernfs_node_id which represents either a 32bit (ino, gen) pair or u64 value. I can't see much value in the usage of the union - all that's needed is a 64bit ID which the current code is already limited to. Using a union makes the code unnecessarily complicated and prevents using 64bit ino without adding practical benefits. This patch drops union kernfs_node_id and makes kernfs_node->id a u64. ino is stored in the lower 32bits and gen upper. Accessors - kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the ino and gen. This simplifies ID handling less cumbersome and will allow using 64bit inos on supported archs. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo Reviewed-by: Greg Kroah-Hartman Cc: Namhyung Kim Cc: Jens Axboe Cc: Alexei Starovoitov

timestamp_truncate: Replace users of timespec64_trunc

2019-08-30T14:27:17Z

Update the inode timestamp updates to use timestamp_truncate() instead of timespec64_trunc(). The change was mostly generated by the following coccinelle script. virtual context virtual patch @r1 depends on patch forall@ struct inode *inode; identifier i_xtime =~ "^i_[acm]time$"; expression e; @@ inode->i_xtime = - timespec64_trunc( + timestamp_truncate( ..., - e); + inode); Signed-off-by: Deepa Dinamani Acked-by: Greg Kroah-Hartman Acked-by: Jeff Layton Cc: adrian.hunter@intel.com Cc: dedekind1@gmail.com Cc: gregkh@linuxfoundation.org Cc: hch@lst.de Cc: jaegeuk@kernel.org Cc: jlbec@evilplan.org Cc: richard@nod.at Cc: tj@kernel.org Cc: yuchao0@huawei.com Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-ntfs-dev@lists.sourceforge.net Cc: linux-mtd@lists.infradead.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16Z

Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Armijn Hemel Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman

kernfs: fix xattr name handling in LSM helpers

2019-04-04T13:00:27Z

The implementation of kernfs_security_xattr_*() helpers reuses the kernfs_node_xattr_*() functions, which take the suffix of the xattr name and extract full xattr name from it using xattr_full_name(). However, this function relies on the fact that the suffix passed to xattr handlers from VFS is always constructed from the full name by just incerementing the pointer. This doesn't necessarily hold for the callers of kernfs_security_xattr_*(), so their usage will easily lead to out-of-bounds access. Fix this by moving the xattr name reconstruction to the VFS xattr handlers and replacing the kernfs_security_xattr_*() helpers with more general kernfs_xattr_*() helpers that take full xattr name and allow accessing all kernfs node's xattrs. Reported-by: kernel test robot Fixes: b230d5aba2d1 ("LSM: add new hook for kernfs node initialization") Fixes: ec882da5cda9 ("selinux: implement the kernfs_init_security hook") Signed-off-by: Ondrej Mosnacek Signed-off-by: Paul Moore

LSM: add new hook for kernfs node initialization

2019-03-21T02:01:02Z

This patch introduces a new security hook that is intended for initializing the security data for newly created kernfs nodes, which provide a way of storing a non-default security context, but need to operate independently from mounts (and therefore may not have an associated inode at the moment of creation). The main motivation is to allow kernfs nodes to inherit the context of the parent under SELinux, similar to the behavior of security_inode_init_security(). Other LSMs may implement their own logic for handling the creation of new nodes. This patch also adds helper functions to for getting/setting security xattrs of a kernfs node so that LSMs hooks are able to do their job. Other important attributes should be accessible direcly in the kernfs_node fields (in case there is need for more, then new helpers should be added to kernfs.h along with the patch that needs them). Signed-off-by: Ondrej Mosnacek Acked-by: Casey Schaufler [PM: more manual merge fixes] Signed-off-by: Paul Moore

kernfs: use simple_xattrs for security attributes

2019-03-21T01:54:33Z

Replace the special handling of security xattrs with simple_xattrs, as is already done for the trusted xattrs. This simplifies the code and allows LSMs to use more than just a single xattr to do their business. Signed-off-by: Ondrej Mosnacek Acked-by: Casey Schaufler [PM: manual merge fixes] Signed-off-by: Paul Moore

kernfs: do not alloc iattrs in kernfs_xattr_get

2019-03-21T01:47:36Z

This is a read-only operation, so we can simply return -ENODATA if kn->iattr is NULL. Signed-off-by: Ondrej Mosnacek Acked-by: Casey Schaufler [PM: minor merge fixes] Signed-off-by: Paul Moore