summaryrefslogtreecommitdiffstats
path: root/fs/nfsd/nfsfh.c
Commit message (Collapse)AuthorAgeFilesLines
* Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-231-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull idmapped mounts from Christian Brauner: "This introduces idmapped mounts which has been in the making for some time. Simply put, different mounts can expose the same file or directory with different ownership. This initial implementation comes with ports for fat, ext4 and with Christoph's port for xfs with more filesystems being actively worked on by independent people and maintainers. Idmapping mounts handle a wide range of long standing use-cases. Here are just a few: - Idmapped mounts make it possible to easily share files between multiple users or multiple machines especially in complex scenarios. For example, idmapped mounts will be used in the implementation of portable home directories in systemd-homed.service(8) where they allow users to move their home directory to an external storage device and use it on multiple computers where they are assigned different uids and gids. This effectively makes it possible to assign random uids and gids at login time. - It is possible to share files from the host with unprivileged containers without having to change ownership permanently through chown(2). - It is possible to idmap a container's rootfs and without having to mangle every file. For example, Chromebooks use it to share the user's Download folder with their unprivileged containers in their Linux subsystem. - It is possible to share files between containers with non-overlapping idmappings. - Filesystem that lack a proper concept of ownership such as fat can use idmapped mounts to implement discretionary access (DAC) permission checking. - They allow users to efficiently changing ownership on a per-mount basis without having to (recursively) chown(2) all files. In contrast to chown (2) changing ownership of large sets of files is instantenous with idmapped mounts. This is especially useful when ownership of a whole root filesystem of a virtual machine or container is changed. With idmapped mounts a single syscall mount_setattr syscall will be sufficient to change the ownership of all files. - Idmapped mounts always take the current ownership into account as idmappings specify what a given uid or gid is supposed to be mapped to. This contrasts with the chown(2) syscall which cannot by itself take the current ownership of the files it changes into account. It simply changes the ownership to the specified uid and gid. This is especially problematic when recursively chown(2)ing a large set of files which is commong with the aforementioned portable home directory and container and vm scenario. - Idmapped mounts allow to change ownership locally, restricting it to specific mounts, and temporarily as the ownership changes only apply as long as the mount exists. Several userspace projects have either already put up patches and pull-requests for this feature or will do so should you decide to pull this: - systemd: In a wide variety of scenarios but especially right away in their implementation of portable home directories. https://systemd.io/HOME_DIRECTORY/ - container runtimes: containerd, runC, LXD:To share data between host and unprivileged containers, unprivileged and privileged containers, etc. The pull request for idmapped mounts support in containerd, the default Kubernetes runtime is already up for quite a while now: https://github.com/containerd/containerd/pull/4734 - The virtio-fs developers and several users have expressed interest in using this feature with virtual machines once virtio-fs is ported. - ChromeOS: Sharing host-directories with unprivileged containers. I've tightly synced with all those projects and all of those listed here have also expressed their need/desire for this feature on the mailing list. For more info on how people use this there's a bunch of talks about this too. Here's just two recent ones: https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf https://fosdem.org/2021/schedule/event/containers_idmap/ This comes with an extensive xfstests suite covering both ext4 and xfs: https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts It covers truncation, creation, opening, xattrs, vfscaps, setid execution, setgid inheritance and more both with idmapped and non-idmapped mounts. It already helped to discover an unrelated xfs setgid inheritance bug which has since been fixed in mainline. It will be sent for inclusion with the xfstests project should you decide to merge this. In order to support per-mount idmappings vfsmounts are marked with user namespaces. The idmapping of the user namespace will be used to map the ids of vfs objects when they are accessed through that mount. By default all vfsmounts are marked with the initial user namespace. The initial user namespace is used to indicate that a mount is not idmapped. All operations behave as before and this is verified in the testsuite. Based on prior discussions we want to attach the whole user namespace and not just a dedicated idmapping struct. This allows us to reuse all the helpers that already exist for dealing with idmappings instead of introducing a whole new range of helpers. In addition, if we decide in the future that we are confident enough to enable unprivileged users to setup idmapped mounts the permission checking can take into account whether the caller is privileged in the user namespace the mount is currently marked with. The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern of extensibility. The following conditions must be met in order to create an idmapped mount: - The caller must currently have the CAP_SYS_ADMIN capability in the user namespace the underlying filesystem has been mounted in. - The underlying filesystem must support idmapped mounts. - The mount must not already be idmapped. This also implies that the idmapping of a mount cannot be altered once it has been idmapped. - The mount must be a detached/anonymous mount, i.e. it must have been created by calling open_tree() with the OPEN_TREE_CLONE flag and it must not already have been visible in the filesystem. The last two points guarantee easier semantics for userspace and the kernel and make the implementation significantly simpler. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes are observed. The manpage with a detailed description can be found here: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The patches to convert individual filesystem are not very large or complicated overall as can be seen from the included fat, ext4, and xfs ports. Patches for other filesystems are actively worked on and will be sent out separately. The xfstestsuite can be used to verify that port has been done correctly. The mount_setattr() syscall is motivated independent of the idmapped mounts patches and it's been around since July 2019. One of the most valuable features of the new mount api is the ability to perform mounts based on file descriptors only. Together with the lookup restrictions available in the openat2() RESOLVE_* flag namespace which we added in v5.6 this is the first time we are close to hardened and race-free (e.g. symlinks) mounting and path resolution. While userspace has started porting to the new mount api to mount proper filesystems and create new bind-mounts it is currently not possible to change mount options of an already existing bind mount in the new mount api since the mount_setattr() syscall is missing. With the addition of the mount_setattr() syscall we remove this last restriction and userspace can now fully port to the new mount api, covering every use-case the old mount api could. We also add the crucial ability to recursively change mount options for a whole mount tree, both removing and adding mount options at the same time. This syscall has been requested multiple times by various people and projects. There is a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. I'll add support for the regular mount binary should you decide to pull this in the following weeks: Here's an example to a simple idmapped mount of another user's home directory: u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r--" * tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits) xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl xfs: support idmapped mounts ext4: support idmapped mounts fat: handle idmapped mounts tests: add mount_setattr() selftests fs: introduce MOUNT_ATTR_IDMAP fs: add mount_setattr() fs: add attr_flags_to_mnt_flags helper fs: split out functions to hold writers namespace: only take read lock in do_reconfigure_mnt() mount: make {lock,unlock}_mount_hash() static namespace: take lock_mount_hash() directly when changing flags nfs: do not export idmapped mounts overlayfs: do not mount on top of idmapped mounts ecryptfs: do not mount on top of idmapped mounts ima: handle idmapped mounts apparmor: handle idmapped mounts fs: make helpers idmap mount aware exec: handle idmapped mounts would_dump: handle idmapped mounts ...
| * namei: make permission helpers idmapped mount awareChristian Brauner2021-01-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The two helpers inode_permission() and generic_permission() are used by the vfs to perform basic permission checking by verifying that the caller is privileged over an inode. In order to handle idmapped mounts we extend the two helpers with an additional user namespace argument. On idmapped mounts the two helpers will make sure to map the inode according to the mount's user namespace and then peform identical permission checks to inode_permission() and generic_permission(). If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* | nfsd: report per-export statsAmir Goldstein2021-01-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Collect some nfsd stats per export in addition to the global stats. A new nfsdfs export_stats file is created. It uses the same ops as the exports file to iterate the export entries and we use the file's name to determine the reported info per export. For example: $ cat /proc/fs/nfsd/export_stats # Version 1.1 # Path Client Start-time # Stats /test localhost 92 fh_stale: 0 io_read: 9 io_write: 1 Every export entry reports the start time when stats collection started, so stats collecting scripts can know if stats where reset between samples. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* | nfsd: protect concurrent access to nfsd stats countersAmir Goldstein2021-01-251-1/+1
|/ | | | | | | | | | | | nfsd stats counters can be updated by concurrent nfsd threads without any protection. Convert some nfsd_stats and nfsd_net struct members to use percpu counters. The longest_chain* members of struct nfsd_net remain unprotected. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* nfsd: Record NFSv4 pre/post-op attributes as non-atomicTrond Myklebust2020-12-091-0/+4
| | | | | | | | For the case of NFSv4, specify to the client that the pre/post-op attributes were not recorded atomically with the main operation. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* nfsd: Fix up nfsd to ensure that timeout errors don't result in ESTALETrond Myklebust2020-12-091-4/+12
| | | | | | | | If the underlying filesystem times out, then we want knfsd to return NFSERR_JUKEBOX/DELAY rather than NFSERR_STALE. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* nfsd: add a new EXPORT_OP_NOWCC flag to struct export_operationsJeff Layton2020-12-091-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With NFSv3 nfsd will always attempt to send along WCC data to the client. This generally involves saving off the in-core inode information prior to doing the operation on the given filehandle, and then issuing a vfs_getattr to it after the op. Some filesystems (particularly clustered or networked ones) have an expensive ->getattr inode operation. Atomicity is also often difficult or impossible to guarantee on such filesystems. For those, we're best off not trying to provide WCC information to the client at all, and to simply allow it to poll for that information as needed with a GETATTR RPC. This patch adds a new flags field to struct export_operations, and defines a new EXPORT_OP_NOWCC flag that filesystems can use to indicate that nfsd should not attempt to provide WCC info in NFSv3 replies. It also adds a blurb about the new flags field and flag to the exporting documentation. The server will also now skip collecting this information for NFSv2 as well, since that info is never used there anyway. Note that this patch does not add this flag to any filesystem export_operations structures. This was originally developed to allow reexporting nfs via nfsd. Other filesystems may want to consider enabling this flag too. It's hard to tell however which ones have export operations to enable export via knfsd and which ones mostly rely on them for open-by-filehandle support, so I'm leaving that up to the individual maintainers to decide. I am cc'ing the relevant lists for those filesystems that I think may want to consider adding this though. Cc: HPDD-discuss@lists.01.org Cc: ceph-devel@vger.kernel.org Cc: cluster-devel@redhat.com Cc: fuse-devel@lists.sourceforge.net Cc: ocfs2-devel@oss.oracle.com Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-231-2/+2
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* nfsd: Add tracing to nfsd_set_fh_dentry()Trond Myklebust2020-03-161-3/+10
| | | | | | | | Add tracing to allow us to figure out where any stale filehandle issues may be originating from. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* nfsd: use true and false for boolean valuesGustavo A. R. Silva2018-08-091-3/+3
| | | | | | | | | | Return statements in functions returning bool should use true or false instead of an integer value. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: don't require low ports for gss requestsJ. Bruce Fields2018-03-191-1/+11
| | | | | | | | | | | | | | | | | | | In a traditional NFS deployment using auth_unix, the clients are trusted to correctly report the credentials of their logged-in users. The server assumes that only root on client machines is allowed to send requests from low-numbered ports, so it can use the originating port number to distinguish "real" NFS clients from NFS clients run by ordinary users, to prevent ordinary users from spoofing credentials. The originating port number on a gss-authenticated request is less important. The authentication ties the request to a user, and we take it as proof that that user authorized the request. The low port number check no longer adds much. So, don't enforce low port numbers in the auth_gss case. Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* nfsd: check d_can_lookup in fh_verify of directoriesJ. Bruce Fields2016-08-041-4/+10
| | | | | | | | | | | | | Create and other nfsd ops generally assume we can call lookup_one_len on inodes with S_IFDIR set. Al says that this assumption isn't true in general, though it should be for the filesystem objects nfsd sees. Add a check just to make sure our assumption isn't violated. Remove a couple checks for i_op->lookup in create code. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: Fix some indent inconsistancyChristophe JAILLET2016-07-131-1/+1
| | | | | | | Silent a few smatch warnings about indentation Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: Correct a comment for NFSD_MAY_ defines locationOleg Drokin2016-07-131-1/+1
| | | | | | | | Those are now defined in fs/nfsd/vfs.h Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Reviewed-by: Jeff Layton <jlayton@poochiereds.net> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* don't bother with ->d_inode->i_sb - it's always equal to ->d_sbAl Viro2016-04-101-1/+1
| | | | | | ... and neither can ever be NULL Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* nfsd: switch unsigned char flags in svc_fh to boolsJeff Layton2015-10-121-4/+1
| | | | | | | ...just for clarity. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-151-10/+10
| | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)David Howells2015-02-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the following where appropriate: (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry). (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry). (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more complicated than it appears as some calls should be converted to d_can_lookup() instead. The difference is whether the directory in question is a real dir with a ->lookup op or whether it's a fake dir with a ->d_automount op. In some circumstances, we can subsume checks for dentry->d_inode not being NULL into this, provided we the code isn't in a filesystem that expects d_inode to be NULL if the dirent really *is* negative (ie. if we're going to use d_inode() rather than d_backing_inode() to get the inode pointer). Note that the dentry type field may be set to something other than DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS manages the fall-through from a negative dentry to a lower layer. In such a case, the dentry type of the negative union dentry is set to the same as the type of the lower dentry. However, if you know d_inode is not NULL at the call site, then you can use the d_is_xxx() functions even in a filesystem. There is one further complication: a 0,0 chardev dentry may be labelled DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was intended for special directory entry types that don't have attached inodes. The following perl+coccinelle script was used: use strict; my @callers; open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') || die "Can't grep for S_ISDIR and co. callers"; @callers = <$fd>; close($fd); unless (@callers) { print "No matches\n"; exit(0); } my @cocci = ( '@@', 'expression E;', '@@', '', '- S_ISLNK(E->d_inode->i_mode)', '+ d_is_symlink(E)', '', '@@', 'expression E;', '@@', '', '- S_ISDIR(E->d_inode->i_mode)', '+ d_is_dir(E)', '', '@@', 'expression E;', '@@', '', '- S_ISREG(E->d_inode->i_mode)', '+ d_is_reg(E)' ); my $coccifile = "tmp.sp.cocci"; open($fd, ">$coccifile") || die $coccifile; print($fd "$_\n") || die $coccifile foreach (@cocci); close($fd); foreach my $file (@callers) { chomp $file; print "Processing ", $file, "\n"; system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 || die "spatch failed"; } [AV: overlayfs parts skipped] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to itJeff Layton2014-12-091-1/+1
| | | | | | | | | | In a later patch, we're going to need some atomic bit flags. Since that field will need to be an unsigned long, we mitigate that space consumption by migrating some other bitflags to the new field. Start with the rq_secure flag. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* NFSD: Put export if prepare_creds() failKinglong Mee2014-09-031-2/+4
| | | | | Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: add appropriate __force directives to filehandle generation codeJeff Layton2014-06-231-1/+8
| | | | | | | | | | | The filehandle structs all use host-endian values, but will sometimes stuff big-endian values into those fields. This is OK since these values are opaque to the client, but it confuses sparse. Add __force to make it clear that we are doing this intentionally. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* NFSD: Using exp_get for export gettingKinglong Mee2014-06-231-2/+1
| | | | | | | Don't using cache_get besides export.h, using exp_get for export. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* SUNRPC/NFSD: Remove using of dprintk with KERN_WARNINGKinglong Mee2014-05-301-3/+2
| | | | | | | | | | | | | | | When debugging, rpc prints messages from dprintk(KERN_WARNING ...) with "^A4" prefixed, [ 2780.339988] ^A4nfsd: connect from unprivileged port: 127.0.0.1, port=35316 Trond tells, > dprintk != printk. We have NEVER supported dprintk(KERN_WARNING...) This patch removes using of dprintk with KERN_WARNING. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: clean up fh_auth usageChristoph Hellwig2014-05-081-11/+9
| | | | | | | | | | | | | | Use fh_fsid when reffering to the fsid part of the filehandle. The variable length auth field envisioned in nfsfh wasn't ever implemented. Also clean up some lose ends around this and document the file handle format better. Btw, why do we even export nfsfh.h to userspace? The file handle very much is kernel private, and nothing in nfs-utils include the header either. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: fh_update should error out in unexpected casesJ. Bruce Fields2013-10-291-5/+3
| | | | | | | | | | | | | | | | | The reporter saw a NULL dereference when a filesystem's ->mknod returned success but left the dentry negative, and then nfsd tried to dereference d_inode (in this case because the CREATE was followed by a GETATTR in the same nfsv4 compound). fh_update already checks for this and another broken case, but for some reason it returns success and leaves nfsd trying to soldier on. If it failed we'd avoid the crash. There's only so much we can do with a buggy filesystem, but it's easy enough to bail out here, so let's do that. Reported-by: Antti Tönkyrä <daedalus@pingtimeout.net> Tested-by: Antti Tönkyrä <daedalus@pingtimeout.net> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: switch to %p[dD]Al Viro2013-10-021-15/+13
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* exportfs: add FILEID_INVALID to indicate invalid fid_typeNamjae Jeon2012-11-071-2/+2
| | | | | | | | | | | This commit adds FILEID_INVALID = 0xff in fid_type to indicate invalid fid_type It avoids using magic number 255 Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: Push mnt_want_write() outside of i_mutexJan Kara2012-07-311-0/+1
| | | | | | | | | | | When mnt_want_write() starts to handle freezing it will get a full lock semantics requiring proper lock ordering. So push mnt_want_write() call consistently outside of i_mutex. CC: linux-nfs@vger.kernel.org CC: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* nfsd: use exp_put() for svc_export_cache putStanislav Kinsbursky2012-04-111-1/+1
| | | | | | | This patch replaces cache_put() call for svc_export_cache by exp_put() call. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* fs: propagate umode_t, misc bitsAl Viro2012-01-031-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* nfsd: clean up nfsd_mode_check()J. Bruce Fields2011-08-261-12/+18
| | | | | | | Add some more comments, simplify logic, do & S_IFMT just once, name "type" more helpfully. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: open-code special directory-hardlink checkJ. Bruce Fields2011-08-261-9/+0
| | | | | | | | We allow the fh_verify caller to specify that any object *except* those of a given type is allowed, by passing a negative type. But only one caller actually uses it. Open-code that check in the one caller. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: allow fh_verify caller to skip pseudoflavor checksJ. Bruce Fields2011-04-111-1/+1
| | | | Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: fix "insecure" export optionJ. Bruce Fields2009-12-201-1/+1
| | | | | | | | | A typo in 12045a6ee9908b "nfsd: let "insecure" flag vary by pseudoflavor" reversed the sense of the "insecure" flag. Reported-by: Michael Guntsche <mike@it-loops.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* nfsd: remove pointless paths in file headersJ. Bruce Fields2009-12-151-2/+0
| | | | | | | | The new .h files have paths at the top that are now out of date. While we're here, just remove all of those from fs/nfsd; they never served any purpose. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: restrict filehandles accepted in V4ROOT caseSteve Dickson2009-12-151-0/+34
| | | | | | | | | | | | | On V4ROOT exports, only accept filehandles that are the *root* of some export. This allows mountd to allow or deny access to individual directories and symlinks on the pseudofilesystem. Note that the checks in readdir and lookup are not enough, since a malicious host with access to the network could guess filehandles that they weren't able to obtain through lookup or readdir. Signed-off-by: Steve Dickson <steved@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: let "insecure" flag vary by pseudoflavorJ. Bruce Fields2009-12-141-1/+3
| | | | | | | | | This was an oversight; it should be among the export flags that can be allowed to vary by pseudoflavor. This allows an administrator to (for example) allow auth_sys mounts only from low ports, but allow auth_krb5 mounts to use any port. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: Move private headers to source directoryBoaz Harrosh2009-12-141-1/+1
| | | | | | | | Lots of include/linux/nfsd/* headers are only used by nfsd module. Move them to the source directory Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: Source files #include cleanupsBoaz Harrosh2009-12-141-9/+0
| | | | | | | | | | | Now that the headers are fixed and carry their own wait, all fs/nfsd/ source files can include a minimal set of headers. and still compile just fine. This patch should improve the compilation speed of the nfsd module. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: simplify fh_verify access checksJ. Bruce Fields2009-11-251-29/+21
| | | | | | | | | | | | | | | | | | | | All nfsd security depends on the security checks in fh_verify, and especially on nfsd_setuser(). It therefore bothers me that the nfsd_setuser call may be made from three different places, depending on whether the filehandle has already been mapped to a dentry, and on whether subtreechecking is in force. Instead, make an unconditional call in fh_verify(), so it's trivial to verify that the call always occurs. That leaves us with a redundant nfsd_setuser() call in the subtreecheck case--it needs the correct user set earlier in order to check execute permissions on the path to this filehandle--but I'm willing to accept that minor inefficiency in the subtreecheck case in return for more straightforward permission checking. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: make fs/nfsd/vfs.h for common includesJ. Bruce Fields2009-11-131-0/+1
| | | | | | | | | | None of this stuff is used outside nfsd, so move it out of the common linux include directory. Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really belongs there, so later we may remove that file entirely. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd4: filehandle leak or error exit from fh_compose()J. Bruce Fields2009-09-041-1/+3
| | | | | | | | | A number of callers (nfsd4_encode_fattr(), at least) don't bother to release the filehandle returned to fh_compose() if fh_compose() returns an error. So, modify fh_compose() to release the filehandle before returning an error. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: move fsid_type choice out of fh_composeJ. Bruce Fields2009-09-021-36/+41
| | | | | | More trivial cleanup. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: move some of fh_compose into helper functionsJ. Bruce Fields2009-09-021-38/+45
| | | | Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* knfsd: remove unreported filehandle stats countersGreg Banks2009-05-271-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The file nfsfh.c contains two static variables nfsd_nr_verified and nfsd_nr_put. These are counters which are incremented as a side effect of the fh_verify() fh_compose() and fh_put() operations, i.e. at least twice per NFS call for any non-trivial workload. Needless to say this makes the cacheline that contains them (and any other innocent victims) a very hot contention point indeed under high call-rate workloads on multiprocessor NFS server. It also turns out that these counters are not used anywhere. They're not reported to userspace, they're not used in logic, they're not even exported from the object file (let alone the module). All they do is waste CPU time. So this patch removes them. Tests on a 16 CPU Altix A4700 with 2 10gige Myricom cards, configured separately (no bonding). Workload is 640 client threads doing directory traverals with random small reads, from server RAM. Before ====== Kernel profile: % cumulative self self total time samples samples calls 1/call 1/call name 6.05 2716.00 2716.00 30406 0.09 1.02 svc_process 4.44 4706.00 1990.00 1975 1.01 1.01 spin_unlock_irqrestore 3.72 6376.00 1670.00 1666 1.00 1.00 svc_export_put 3.41 7907.00 1531.00 1786 0.86 1.02 nfsd_ofcache_lookup 3.25 9363.00 1456.00 10965 0.13 1.01 nfsd_dispatch 3.10 10752.00 1389.00 1376 1.01 1.01 nfsd_cache_lookup 2.57 11907.00 1155.00 4517 0.26 1.03 svc_tcp_recvfrom ... 2.21 15352.00 1003.00 1081 0.93 1.00 nfsd_choose_ofc <---- ^^^^ Here the function nfsd_choose_ofc() reads a global variable which by accident happened to be located in the same cacheline as nfsd_nr_verified. Call rate: nullarbor:~ # pmdumptext nfs3.server.calls ... Thu Dec 13 00:15:27 184780.663 Thu Dec 13 00:15:28 184885.881 Thu Dec 13 00:15:29 184449.215 Thu Dec 13 00:15:30 184971.058 Thu Dec 13 00:15:31 185036.052 Thu Dec 13 00:15:32 185250.475 Thu Dec 13 00:15:33 184481.319 Thu Dec 13 00:15:34 185225.737 Thu Dec 13 00:15:35 185408.018 Thu Dec 13 00:15:36 185335.764 After ===== kernel profile: % cumulative self self total time samples samples calls 1/call 1/call name 6.33 2813.00 2813.00 29979 0.09 1.01 svc_process 4.66 4883.00 2070.00 2065 1.00 1.00 spin_unlock_irqrestore 4.06 6687.00 1804.00 2182 0.83 1.00 nfsd_ofcache_lookup 3.20 8110.00 1423.00 10932 0.13 1.00 nfsd_dispatch 3.03 9456.00 1346.00 1343 1.00 1.00 nfsd_cache_lookup 2.62 10622.00 1166.00 4645 0.25 1.01 svc_tcp_recvfrom [...] 0.10 42586.00 44.00 74 0.59 1.00 nfsd_choose_ofc <--- HA!! ^^^^ Call rate: nullarbor:~ # pmdumptext nfs3.server.calls ... Thu Dec 13 01:45:28 194677.118 Thu Dec 13 01:45:29 193932.692 Thu Dec 13 01:45:30 194294.364 Thu Dec 13 01:45:31 194971.276 Thu Dec 13 01:45:32 194111.207 Thu Dec 13 01:45:33 194999.635 Thu Dec 13 01:45:34 195312.594 Thu Dec 13 01:45:35 195707.293 Thu Dec 13 01:45:36 194610.353 Thu Dec 13 01:45:37 195913.662 Thu Dec 13 01:45:38 194808.675 i.e. about a 5.3% improvement in call rate. Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Reviewed-by: David Chinner <dgc@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* NFSD: FIDs need to take precedence over UUIDsSteve Dickson2009-01-071-3/+3
| | | | | | | | | When determining the fsid_type in fh_compose(), the setting of the FID via fsid= export option needs to take precedence over using the UUID device id. Signed-off-by: Steve Dickson <steved@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* nfsd: update fh_verify descriptionJ. Bruce Fields2009-01-061-6/+24
| | | | Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* CRED: Inaugurate COW credentialsDavid Howells2008-11-141-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Inaugurate copy-on-write credentials management. This uses RCU to manage the credentials pointer in the task_struct with respect to accesses by other tasks. A process may only modify its own credentials, and so does not need locking to access or modify its own credentials. A mutex (cred_replace_mutex) is added to the task_struct to control the effect of PTRACE_ATTACHED on credential calculations, particularly with respect to execve(). With this patch, the contents of an active credentials struct may not be changed directly; rather a new set of credentials must be prepared, modified and committed using something like the following sequence of events: struct cred *new = prepare_creds(); int ret = blah(new); if (ret < 0) { abort_creds(new); return ret; } return commit_creds(new); There are some exceptions to this rule: the keyrings pointed to by the active credentials may be instantiated - keyrings violate the COW rule as managing COW keyrings is tricky, given that it is possible for a task to directly alter the keys in a keyring in use by another task. To help enforce this, various pointers to sets of credentials, such as those in the task_struct, are declared const. The purpose of this is compile-time discouragement of altering credentials through those pointers. Once a set of credentials has been made public through one of these pointers, it may not be modified, except under special circumstances: (1) Its reference count may incremented and decremented. (2) The keyrings to which it points may be modified, but not replaced. The only safe way to modify anything else is to create a replacement and commit using the functions described in Documentation/credentials.txt (which will be added by a later patch). This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). This now prepares and commits credentials in various places in the security code rather than altering the current creds directly. (2) Temporary credential overrides. do_coredump() and sys_faccessat() now prepare their own credentials and temporarily override the ones currently on the acting thread, whilst preventing interference from other threads by holding cred_replace_mutex on the thread being dumped. This will be replaced in a future patch by something that hands down the credentials directly to the functions being called, rather than altering the task's objective credentials. (3) LSM interface. A number of functions have been changed, added or removed: (*) security_capset_check(), ->capset_check() (*) security_capset_set(), ->capset_set() Removed in favour of security_capset(). (*) security_capset(), ->capset() New. This is passed a pointer to the new creds, a pointer to the old creds and the proposed capability sets. It should fill in the new creds or return an error. All pointers, barring the pointer to the new creds, are now const. (*) security_bprm_apply_creds(), ->bprm_apply_creds() Changed; now returns a value, which will cause the process to be killed if it's an error. (*) security_task_alloc(), ->task_alloc_security() Removed in favour of security_prepare_creds(). (*) security_cred_free(), ->cred_free() New. Free security data attached to cred->security. (*) security_prepare_creds(), ->cred_prepare() New. Duplicate any security data attached to cred->security. (*) security_commit_creds(), ->cred_commit() New. Apply any security effects for the upcoming installation of new security by commit_creds(). (*) security_task_post_setuid(), ->task_post_setuid() Removed in favour of security_task_fix_setuid(). (*) security_task_fix_setuid(), ->task_fix_setuid() Fix up the proposed new credentials for setuid(). This is used by cap_set_fix_setuid() to implicitly adjust capabilities in line with setuid() changes. Changes are made to the new credentials, rather than the task itself as in security_task_post_setuid(). (*) security_task_reparent_to_init(), ->task_reparent_to_init() Removed. Instead the task being reparented to init is referred directly to init's credentials. NOTE! This results in the loss of some state: SELinux's osid no longer records the sid of the thread that forked it. (*) security_key_alloc(), ->key_alloc() (*) security_key_permission(), ->key_permission() Changed. These now take cred pointers rather than task pointers to refer to the security context. (4) sys_capset(). This has been simplified and uses less locking. The LSM functions it calls have been merged. (5) reparent_to_kthreadd(). This gives the current thread the same credentials as init by simply using commit_thread() to point that way. (6) __sigqueue_alloc() and switch_uid() __sigqueue_alloc() can't stop the target task from changing its creds beneath it, so this function gets a reference to the currently applicable user_struct which it then passes into the sigqueue struct it returns if successful. switch_uid() is now called from commit_creds(), and possibly should be folded into that. commit_creds() should take care of protecting __sigqueue_alloc(). (7) [sg]et[ug]id() and co and [sg]et_current_groups. The set functions now all use prepare_creds(), commit_creds() and abort_creds() to build and check a new set of credentials before applying it. security_task_set[ug]id() is called inside the prepared section. This guarantees that nothing else will affect the creds until we've finished. The calling of set_dumpable() has been moved into commit_creds(). Much of the functionality of set_user() has been moved into commit_creds(). The get functions all simply access the data directly. (8) security_task_prctl() and cap_task_prctl(). security_task_prctl() has been modified to return -ENOSYS if it doesn't want to handle a function, or otherwise return the return value directly rather than through an argument. Additionally, cap_task_prctl() now prepares a new set of credentials, even if it doesn't end up using it. (9) Keyrings. A number of changes have been made to the keyrings code: (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have all been dropped and built in to the credentials functions directly. They may want separating out again later. (b) key_alloc() and search_process_keyrings() now take a cred pointer rather than a task pointer to specify the security context. (c) copy_creds() gives a new thread within the same thread group a new thread keyring if its parent had one, otherwise it discards the thread keyring. (d) The authorisation key now points directly to the credentials to extend the search into rather pointing to the task that carries them. (e) Installing thread, process or session keyrings causes a new set of credentials to be created, even though it's not strictly necessary for process or session keyrings (they're shared). (10) Usermode helper. The usermode helper code now carries a cred struct pointer in its subprocess_info struct instead of a new session keyring pointer. This set of credentials is derived from init_cred and installed on the new process after it has been cloned. call_usermodehelper_setup() allocates the new credentials and call_usermodehelper_freeinfo() discards them if they haven't been used. A special cred function (prepare_usermodeinfo_creds()) is provided specifically for call_usermodehelper_setup() to call. call_usermodehelper_setkeys() adjusts the credentials to sport the supplied keyring as the new session keyring. (11) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) selinux_setprocattr() no longer does its check for whether the current ptracer can access processes with the new SID inside the lock that covers getting the ptracer's SID. Whilst this lock ensures that the check is done with the ptracer pinned, the result is only valid until the lock is released, so there's no point doing it inside the lock. (12) is_single_threaded(). This function has been extracted from selinux_setprocattr() and put into a file of its own in the lib/ directory as join_session_keyring() now wants to use it too. The code in SELinux just checked to see whether a task shared mm_structs with other tasks (CLONE_VM), but that isn't good enough. We really want to know if they're part of the same thread group (CLONE_THREAD). (13) nfsd. The NFS server daemon now has to use the COW credentials to set the credentials it is going to use. It really needs to pass the credentials down to the functions it calls, but it can't do that until other patches in this series have been applied. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Separate task security context from task_structDavid Howells2008-11-141-3/+3
| | | | | | | | | | | | | | | | Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-09 00:39:16 +0000