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2021-01-24fs: make helpers idmap mount awareChristian Brauner1-4/+5
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24acl: handle idmapped mountsChristian Brauner1-21/+58
The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24inode: make init and permission helpers idmapped mount awareChristian Brauner1-1/+1
The inode_owner_or_capable() helper determines whether the caller is the owner of the inode or is capable with respect to that inode. Allow it to handle idmapped mounts. If the inode is accessed through an idmapped mount it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Similarly, allow the inode_init_owner() helper to handle idmapped mounts. It initializes a new inode on idmapped mounts by mapping the fsuid and fsgid of the caller from the mount's user namespace. 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/20210121131959.646623-7-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24namei: make permission helpers idmapped mount awareChristian Brauner1-5/+12
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>
2021-01-24capability: handle idmapped mountsChristian Brauner1-1/+1
In order to determine whether a caller holds privilege over a given inode the capability framework exposes the two helpers privileged_wrt_inode_uidgid() and capable_wrt_inode_uidgid(). The former verifies that the inode has a mapping in the caller's user namespace and the latter additionally verifies that the caller has the requested capability in their current user namespace. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the checks are identical to non-idmapped inodes. If the initial user namespace is passed all operations are a nop so non-idmapped mounts will not see a change in behavior. Link: https://lore.kernel.org/r/20210121131959.646623-5-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>
2020-06-08vfs: clean up posix_acl_permission() logic aroudn MAY_NOT_BLOCKLinus Torvalds1-1/+1
posix_acl_permission() does not care about MAY_NOT_BLOCK, and in fact the permission logic internally must not check that bit (it's only for upper layers to decide whether they can block to do IO to look up the acl information or not). But the way the code was written, it _looked_ like it cared, since the function explicitly did not mask that bit off. But it has exactly two callers: one for when that bit is set, which first clears the bit before calling posix_acl_permission(), and the other call site when that bit was clear. So stop the silly games "saving" the MAY_NOT_BLOCK bit that must not be used for the actual permission test, and that currently is pointlessly cleared by the callers when the function itself should just not care. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-04fs/posix_acl.c: fix kernel-doc warningsRandy Dunlap1-2/+5
Fix kernel-doc warnings in fs/posix_acl.c. Also fix one typo (setgit -> setgid). fs/posix_acl.c:647: warning: Function parameter or member 'inode' not described in 'posix_acl_update_mode' fs/posix_acl.c:647: warning: Function parameter or member 'mode_p' not described in 'posix_acl_update_mode' fs/posix_acl.c:647: warning: Function parameter or member 'acl' not described in 'posix_acl_update_mode' Link: http://lkml.kernel.org/r/29b0dc46-1f28-a4e5-b1d0-ba2b65629779@infradead.org Fixes: 073931017b49d ("posix_acl: Clear SGID bit when setting file permissions") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_tElena Reshetova1-3/+3
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable posix_acl.a_refcount is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the posix_acl.a_refcount it might make a difference in following places: - get_cached_acl(): increment in refcount_inc_not_zero() only guarantees control dependency on success vs. fully ordered atomic counterpart. However this operation is performed under rcu_read_lock(), so this should be fine. - posix_acl_release(): decrement in refcount_dec_and_test() only provides RELEASE ordering and control dependency on success vs. fully ordered atomic counterpart Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-03-02sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar1-0/+1
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-10tmpfs: clear S_ISGID when setting posix ACLsGu Zheng1-5/+4
This change was missed the tmpfs modification in In CVE-2016-7097 commit 073931017b49 ("posix_acl: Clear SGID bit when setting file permissions") It can test by xfstest generic/375, which failed to clear setgid bit in the following test case on tmpfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Signed-off-by: Gu Zheng <guzheng1@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-08Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro1-0/+31
2016-10-08Merge remote-tracking branch 'ovl/misc' into work.miscAl Viro1-5/+6
2016-09-27posix_acl: xattr representation cleanupsAndreas Gruenbacher1-9/+9
Remove the unnecessary typedefs and the zero-length a_entries array in struct posix_acl_xattr_header. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani1-1/+1
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-22posix_acl: Clear SGID bit when setting file permissionsJan Kara1-0/+31
When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2016-09-16posix_acl: don't ignore return value of posix_acl_create_masq()Miklos Szeredi1-5/+6
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com>
2016-07-29Merge branch 'for-linus' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns vfs updates from Eric Biederman: "This tree contains some very long awaited work on generalizing the user namespace support for mounting filesystems to include filesystems with a backing store. The real world target is fuse but the goal is to update the vfs to allow any filesystem to be supported. This patchset is based on a lot of code review and testing to approach that goal. While looking at what is needed to support the fuse filesystem it became clear that there were things like xattrs for security modules that needed special treatment. That the resolution of those concerns would not be fuse specific. That sorting out these general issues made most sense at the generic level, where the right people could be drawn into the conversation, and the issues could be solved for everyone. At a high level what this patchset does a couple of simple things: - Add a user namespace owner (s_user_ns) to struct super_block. - Teach the vfs to handle filesystem uids and gids not mapping into to kuids and kgids and being reported as INVALID_UID and INVALID_GID in vfs data structures. By assigning a user namespace owner filesystems that are mounted with only user namespace privilege can be detected. This allows security modules and the like to know which mounts may not be trusted. This also allows the set of uids and gids that are communicated to the filesystem to be capped at the set of kuids and kgids that are in the owning user namespace of the filesystem. One of the crazier corner casees this handles is the case of inodes whose i_uid or i_gid are not mapped into the vfs. Most of the code simply doesn't care but it is easy to confuse the inode writeback path so no operation that could cause an inode write-back is permitted for such inodes (aka only reads are allowed). This set of changes starts out by cleaning up the code paths involved in user namespace permirted mounts. Then when things are clean enough adds code that cleanly sets s_user_ns. Then additional restrictions are added that are possible now that the filesystem superblock contains owner information. These changes should not affect anyone in practice, but there are some parts of these restrictions that are changes in behavior. - Andy's restriction on suid executables that does not honor the suid bit when the path is from another mount namespace (think /proc/[pid]/fd/) or when the filesystem was mounted by a less privileged user. - The replacement of the user namespace implicit setting of MNT_NODEV with implicitly setting SB_I_NODEV on the filesystem superblock instead. Using SB_I_NODEV is a stronger form that happens to make this state user invisible. The user visibility can be managed but it caused problems when it was introduced from applications reasonably expecting mount flags to be what they were set to. There is a little bit of work remaining before it is safe to support mounting filesystems with backing store in user namespaces, beyond what is in this set of changes. - Verifying the mounter has permission to read/write the block device during mount. - Teaching the integrity modules IMA and EVM to handle filesystems mounted with only user namespace root and to reduce trust in their security xattrs accordingly. - Capturing the mounters credentials and using that for permission checks in d_automount and the like. (Given that overlayfs already does this, and we need the work in d_automount it make sense to generalize this case). Furthermore there are a few changes that are on the wishlist: - Get all filesystems supporting posix acls using the generic posix acls so that posix_acl_fix_xattr_from_user and posix_acl_fix_xattr_to_user may be removed. [Maintainability] - Reducing the permission checks in places such as remount to allow the superblock owner to perform them. - Allowing the superblock owner to chown files with unmapped uids and gids to something that is mapped so the files may be treated normally. I am not considering even obvious relaxations of permission checks until it is clear there are no more corner cases that need to be locked down and handled generically. Many thanks to Seth Forshee who kept this code alive, and putting up with me rewriting substantial portions of what he did to handle more corner cases, and for his diligent testing and reviewing of my changes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits) fs: Call d_automount with the filesystems creds fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns evm: Translate user/group ids relative to s_user_ns when computing HMAC dquot: For now explicitly don't support filesystems outside of init_user_ns quota: Handle quota data stored in s_user_ns in quota_setxquota quota: Ensure qids map to the filesystem vfs: Don't create inodes with a uid or gid unknown to the vfs vfs: Don't modify inodes with a uid or gid unknown to the vfs cred: Reject inodes with invalid ids in set_create_file_as() fs: Check for invalid i_uid in may_follow_link() vfs: Verify acls are valid within superblock's s_user_ns. userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS fs: Refuse uid/gid changes which don't map into s_user_ns selinux: Add support for unprivileged mounts from user namespaces Smack: Handle labels consistently in untrusted mounts Smack: Add support for unprivileged mounts from user namespaces fs: Treat foreign mounts as nosuid fs: Limit file caps to the user namespace of the super block userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag userns: Remove implicit MNT_NODEV fragility. ...
2016-06-30vfs: Verify acls are valid within superblock's s_user_ns.Eric W. Biederman1-4/+4
Update posix_acl_valid to verify that an acl is within a user namespace. Update the callers of posix_acl_valid to pass in an appropriate user namespace. For posix_acl_xattr_set and v9fs_xattr_set_acl pass in inode->i_sb->s_user_ns to posix_acl_valid. For md_unpack_acl pass in &init_user_ns as no inode or superblock is in sight. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-24posix_acl: Add set_posix_aclAndreas Gruenbacher1-19/+23
Factor out part of posix_acl_xattr_set into a common function that takes a posix_acl, which nfsd can also call. The prototype already exists in include/linux/posix_acl.h. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: stable@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-27switch xattr_handler->set() to passing dentry and inode separatelyAl Viro1-3/+3
preparation for similar switch in ->setxattr() (see the next commit for rationale). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10xattr_handler: pass dentry and inode as separate arguments of ->get()Al Viro1-5/+5
... and do not assume they are already attached to each other Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-31posix_acl: Unexport acl_by_type and make it staticAndreas Gruenbacher1-2/+1
acl_by_type(inode, type) returns a pointer to either inode->i_acl or inode->i_default_acl depending on type. This is useful in fs/posix_acl.c, but should never have been visible outside that file. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-31posix_acl: Inode acl caching fixesAndreas Gruenbacher1-34/+69
When get_acl() is called for an inode whose ACL is not cached yet, the get_acl inode operation is called to fetch the ACL from the filesystem. The inode operation is responsible for updating the cached acl with set_cached_acl(). This is done without locking at the VFS level, so another task can call set_cached_acl() or forget_cached_acl() before the get_acl inode operation gets to calling set_cached_acl(), and then get_acl's call to set_cached_acl() results in caching an outdate ACL. Prevent this from happening by setting the cached ACL pointer to a task-specific sentinel value before calling the get_acl inode operation. Move the responsibility for updating the cached ACL from the get_acl inode operations to get_acl(). There, only set the cached ACL if the sentinel value hasn't changed. The sentinel values are chosen to have odd values. Likewise, the value of ACL_NOT_CACHED is odd. In contrast, ACL object pointers always have an even value (ACLs are aligned in memory). This allows to distinguish uncached ACLs values from ACL objects. In addition, switch from guarding inode->i_acl and inode->i_default_acl upates by the inode->i_lock spinlock to using xchg() and cmpxchg(). Filesystems that do not want ACLs returned from their get_acl inode operations to be cached must call forget_cached_acl() to prevent the VFS from doing so. (Patch written by Al Viro and Andreas Gruenbacher.) Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-13xattr handlers: Simplify list operationAndreas Gruenbacher1-14/+3
Change the list operation to only return whether or not an attribute should be listed. Copying the attribute names into the buffer is moved to the callers. Since the result only depends on the dentry and not on the attribute name, we do not pass the attribute name to list operations. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06vfs: Distinguish between full xattr names and proper prefixesAndreas Gruenbacher1-7/+3
Add an additional "name" field to struct xattr_handler. When the name is set, the handler matches attributes with exactly that name. When the prefix is set instead, the handler matches attributes with the given prefix and with a non-empty suffix. This patch should avoid bugs like the one fixed in commit c361016a in the future. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06posix acls: Remove duplicate xattr name definitionsAndreas Gruenbacher1-2/+2
Remove POSIX_ACL_XATTR_{ACCESS,DEFAULT} and GFS2_POSIX_ACL_{ACCESS,DEFAULT} and replace them with the definitions in <include/uapi/linux/xattr.h>. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-13xattr handlers: Pass handler to operations instead of flagsAndreas Gruenbacher1-15/+13
The xattr_handler operations are currently all passed a file system specific flags value which the operations can use to disambiguate between different handlers; some file systems use that to distinguish the xattr namespace, for example. In some oprations, it would be useful to also have access to the handler prefix. To allow that, pass a pointer to the handler to operations instead of the flags value alone. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-13vfs: Fix the posix_acl_xattr_list return valueAndreas Gruenbacher1-3/+1
When a filesystem that contains POSIX ACLs is mounted without ACL support (-o noacl), the appropriate behavior is not to list any existing POSIX ACL xattrs. The return value for list xattr handlers in this case is 0, not an error code: several filesystems that use the POSIX ACL xattr handlers do not expect the list operation to fail. Symlinks cannot have ACLs, so posix_acl_xattr_list will never be called for symlinks in the first place. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-13vfs: Check attribute names in posix acl xattr handersAndreas Gruenbacher1-0/+4
The get and set operations of the POSIX ACL xattr handlers failed to check the attribute names, so all names with "system.posix_acl_access" or "system.posix_acl_default" as a prefix were accepted. Reject invalid names from now on. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23fs/posix_acl.c: make posix_acl_create() safer and cleanerDan Carpenter1-26/+20
If posix_acl_create() returns an error code then "*acl" and "*default_acl" can be uninitialized or point to freed memory. This is a dangerous thing to do. For example, it causes a problem in ocfs2_reflink(): fs/ocfs2/refcounttree.c:4327 ocfs2_reflink() error: potentially using uninitialized 'default_acl'. I've re-written this so we set the pointers to NULL at the start. I've added a temporary "clone" variable to hold the value of "*acl" until end. Setting them to NULL means means we don't need the "no_acl" label. We may as well remove the "apply_umask" stuff forward and remove that label as well. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2015-04-15VFS: assorted d_backing_inode() annotationsDavid Howells1-4/+4
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)David Howells1-2/+2
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>
2015-02-20posix_acl: fix reference leaks in posix_acl_createOmar Sandoval1-5/+9
get_acl gets a reference which we must release in the error cases. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06posix_acl: handle NULL ACL in posix_acl_equiv_modeChristoph Hellwig1-0/+6
Various filesystems don't bother checking for a NULL ACL in posix_acl_equiv_mode, and thus can dereference a NULL pointer when it gets passed one. This usually happens from the NFS server, as the ACL tools never pass a NULL ACL, but instead of one representing the mode bits. Instead of adding boilerplat to all filesystems put this check into one place, which will allow us to remove the check from other filesystems as well later on. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Ben Greear <greearb@candelatech.com> Reported-by: Marco Munderloh <munderl@tnt.uni-hannover.de>, Cc: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-04Merge tag 'gfs2-merge-window' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw Pull GFS2 updates from Steven Whitehouse: "One of the main highlights this time, is not the patches themselves but instead the widening contributor base. It is good to see that interest is increasing in GFS2, and I'd like to thank all the contributors to this patch set. In addition to the usual set of bug fixes and clean ups, there are patches to improve inode creation performance when xattrs are required and some improvements to the transaction code which is intended to help improve scalability after further changes in due course. Journal extent mapping is also updated to make it more efficient and again, this is a foundation for future work in this area. The maximum number of ACLs has been increased to 300 (for a 4k block size) which means that even with a few additional xattrs from selinux, everything should fit within a single fs block. There is also a patch to bring GFS2's own copy of the writepages code up to the same level as the core VFS. Eventually we may be able to merge some of this code, since it is fairly similar. The other major change this time, is bringing consistency to the printing of messages via fs_<level>, pr_<level> macros" * tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: (29 commits) GFS2: Fix address space from page function GFS2: Fix uninitialized VFS inode in gfs2_create_inode GFS2: Fix return value in slot_get() GFS2: inline function gfs2_set_mode GFS2: Remove extraneous function gfs2_security_init GFS2: Increase the max number of ACLs GFS2: Re-add a call to log_flush_wait when flushing the journal GFS2: Ensure workqueue is scheduled after noexp request GFS2: check NULL return value in gfs2_ok_to_move GFS2: Convert gfs2_lm_withdraw to use fs_err GFS2: Use fs_<level> more often GFS2: Use pr_<level> more consistently GFS2: Move recovery variables to journal structure in memory GFS2: global conversion to pr_foo() GFS2: return -E2BIG if hit the maximum limits of ACLs GFS2: Clean up journal extent mapping GFS2: replace kmalloc - __vmalloc / memset 0 GFS2: Remove extra "if" in gfs2_log_flush() fs: NULL dereference in posix_acl_to_xattr() GFS2: Move log buffer accounting to transaction ...
2014-02-25fs: NULL dereference in posix_acl_to_xattr()Dan Carpenter1-2/+3
This patch moves the dereference of "buffer" after the check for NULL. The only place which passes a NULL parameter is gfs2_set_acl(). Cc: stable <stable@vger.kernel.org> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-03fs: get_acl() must be allowed to return EOPNOTSUPPTrond Myklebust1-6/+12
posix_acl_xattr_get requires get_acl() to return EOPNOTSUPP if the filesystem cannot support acls. This is needed for NFS, which can't know whether or not the server supports acls until it tries to get/set one. This patch converts posix_acl_chmod and posix_acl_create to deal with EOPNOTSUPP return values from get_acl(). Reported-by: Russell King <linux@arm.linux.org.uk> Link: http://lkml.kernel.org/r/20140130140834.GW15937@n2100.arm.linux.org.uk Cc: Al Viro viro@zeniv.linux.org.uk> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-28Merge branch 'for-linus' of ↵Linus Torvalds1-12/+416
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Assorted stuff; the biggest pile here is Christoph's ACL series. Plus assorted cleanups and fixes all over the place... There will be another pile later this week" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits) __dentry_path() fixes vfs: Remove second variable named error in __dentry_path vfs: Is mounted should be testing mnt_ns for NULL or error. Fix race when checking i_size on direct i/o read hfsplus: remove can_set_xattr nfsd: use get_acl and ->set_acl fs: remove generic_acl nfs: use generic posix ACL infrastructure for v3 Posix ACLs gfs2: use generic posix ACL infrastructure jfs: use generic posix ACL infrastructure xfs: use generic posix ACL infrastructure reiserfs: use generic posix ACL infrastructure ocfs2: use generic posix ACL infrastructure jffs2: use generic posix ACL infrastructure hfsplus: use generic posix ACL infrastructure f2fs: use generic posix ACL infrastructure ext2/3/4: use generic posix ACL infrastructure btrfs: use generic posix ACL infrastructure fs: make posix_acl_create more useful fs: make posix_acl_chmod more useful ...
2014-01-26fs: remove generic_aclChristoph Hellwig1-0/+36
And instead convert tmpfs to use the new generic ACL code, with two stub methods provided for in-memory filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: make posix_acl_create more usefulChristoph Hellwig1-4/+53
Rename the current posix_acl_created to __posix_acl_create and add a fully featured helper to set up the ACLs on file creation that uses get_acl(). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: make posix_acl_chmod more usefulChristoph Hellwig1-3/+27
Rename the current posix_acl_chmod to __posix_acl_chmod and add a fully featured ACL chmod helper that uses the ->set_acl inode operation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: add generic xattr_acl handlersChristoph Hellwig1-0/+102
With the ->set_acl inode operation we can implement the Posix ACL xattr handlers in generic code instead of duplicating them all over the tree. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: add get_acl helperChristoph Hellwig1-0/+27
Factor out the code to get an ACL either from the inode or disk from check_acl, so that it can be used elsewhere later on. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: merge xattr_acl.c into posix_acl.cChristoph Hellwig1-7/+173
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-23userns: relax the posix_acl_valid() checksAndreas Gruenbacher1-10/+0
So far, POSIX ACLs are using a canonical representation that keeps all ACL entries in a strict order; the ACL_USER and ACL_GROUP entries for specific users and groups are ordered by user and group identifier, respectively. The user-space code provides ACL entries in this order; the kernel verifies that the ACL entry order is correct in posix_acl_valid(). User namespaces allow to arbitrary map user and group identifiers which can cause the ACL_USER and ACL_GROUP entry order to differ between user space and the kernel; posix_acl_valid() would then fail. Work around this by allowing ACL_USER and ACL_GROUP entries to be in any order in the kernel. The effect is only minor: file permission checks will pick the first matching ACL_USER entry, and check all matching ACL_GROUP entries. (The libacl user-space library and getfacl / setfacl tools will not create ACLs with duplicate user or group idenfifiers; they will handle ACLs with entries in an arbitrary order correctly.) Signed-off-by: Andreas Gruenbacher <agruen@linbit.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21posix_acl: uninliningAndrew Morton1-5/+79
Uninline vast tracts of nested inline functions in include/linux/posix_acl.h. This reduces the text+data+bss size of x86_64 allyesconfig vmlinux by 8026 bytes. The patch also regularises the positioning of the EXPORT_SYMBOLs in posix_acl.c. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Tested-by: Benny Halevy <bhalevy@primarydata.com> Cc: Benny Halevy <bhalevy@panasas.com> Cc: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-18userns: Convert vfs posix_acl support to use kuids and kgidsEric W. Biederman1-15/+15
- In setxattr if we are setting a posix acl convert uids and gids from the current user namespace into the initial user namespace, before the xattrs are passed to the underlying filesystem. Untranslatable uids and gids are represented as -1 which posix_acl_from_xattr will represent as INVALID_UID or INVALID_GID. posix_acl_valid will fail if an acl from userspace has any INVALID_UID or INVALID_GID values. In net this guarantees that untranslatable posix acls will not be stored by filesystems. - In getxattr if we are reading a posix acl convert uids and gids from the initial user namespace into the current user namespace. Uids and gids that can not be tranlsated into the current user namespace will be represented as -1. - Replace e_id in struct posix_acl_entry with an anymouns union of e_uid and e_gid. For the short term retain the e_id field until all of the users are converted. - Don't set struct posix_acl.e_id in the cases where the acl type does not use e_id. Greatly reducing the use of ACL_UNDEFINED_ID. - Rework the ordering checks in posix_acl_valid so that I use kuid_t and kgid_t types throughout the code, and so that I don't need arithmetic on uid and gid types. Cc: Theodore Tso <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-02-28fs: reduce the use of module.h wherever possiblePaul Gortmaker1-1/+1
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>