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* fs: make helpers idmap mount awareChristian Brauner2021-01-24170-703/+1037
| | | | | | | | | | | | | | | | | | | | | 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>
* exec: handle idmapped mountsChristian Brauner2021-01-241-2/+5
| | | | | | | | | | | | | | | | | | | | When executing a setuid binary the kernel will verify in bprm_fill_uid() that the inode has a mapping in the caller's user namespace before setting the callers uid and gid. Let bprm_fill_uid() handle idmapped mounts. If the inode is accessed through an idmapped mount it is mapped 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. Link: https://lore.kernel.org/r/20210121131959.646623-24-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>
* would_dump: handle idmapped mountsChristian Brauner2021-01-241-3/+3
| | | | | | | | | | | | | | | | When determining whether or not to create a coredump the vfs will verify that the caller is privileged over the inode. Make the would_dump() helper handle idmapped mounts by passing down the mount's user namespace of the exec file. 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/20210121131959.646623-23-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>
* ioctl: handle idmapped mountsChristian Brauner2021-01-241-2/+5
| | | | | | | | | | | | | | | Enable generic ioctls to handle idmapped mounts by passing down 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/20210121131959.646623-22-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>
* init: handle idmapped mountsChristian Brauner2021-01-241-9/+11
| | | | | | | | | | | | | | Enable the init helpers to handle idmapped mounts by passing down 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/20210121131959.646623-21-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>
* fcntl: handle idmapped mountsChristian Brauner2021-01-241-1/+2
| | | | | | | | | | | | | | | Enable the setfl() helper to handle idmapped mounts by passing down 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/20210121131959.646623-20-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>
* utimes: handle idmapped mountsChristian Brauner2021-01-241-1/+1
| | | | | | | | | | | | | | | | Enable the vfs_utimes() helper to handle idmapped mounts by passing down 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/20210121131959.646623-19-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>
* open: handle idmapped mountsChristian Brauner2021-01-241-4/+9
| | | | | | | | | | | | | | | | | | | | | For core file operations such as changing directories or chrooting, determining file access, changing mode or ownership the vfs will verify that the caller is privileged over the inode. Extend the various helpers to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the permissions checks are identical to non-idmapped mounts. When changing file ownership we need to map the uid and gid 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/20210121131959.646623-17-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: James Morris <jamorris@linux.microsoft.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* open: handle idmapped mounts in do_truncate()Christian Brauner2021-01-244-14/+21
| | | | | | | | | | | | | | | | | When truncating files the vfs will verify that the caller is privileged over the inode. Extend it to handle idmapped mounts. If the inode is accessed through an idmapped mount it is mapped according to the mount's user namespace. Afterwards the permissions 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. Link: https://lore.kernel.org/r/20210121131959.646623-16-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>
* namei: prepare for idmapped mountsChristian Brauner2021-01-248-88/+247
| | | | | | | | | | | | | | | | | | | The various vfs_*() helpers are called by filesystems or by the vfs itself to perform core operations such as create, link, mkdir, mknod, rename, rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace and pass it down. Afterwards the checks and operations 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. Link: https://lore.kernel.org/r/20210121131959.646623-15-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>
* namei: introduce struct renamedataChristian Brauner2021-01-245-13/+44
| | | | | | | | | | | | | | | In order to handle idmapped mounts we will extend the vfs rename helper to take two new arguments in follow up patches. Since this operations already takes a bunch of arguments add a simple struct renamedata and make the current helper use it before we extend it. Link: https://lore.kernel.org/r/20210121131959.646623-14-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>
* namei: handle idmapped mounts in may_*() helpersChristian Brauner2021-01-246-62/+99
| | | | | | | | | | | | | | | | | | | | | | | The may_follow_link(), may_linkat(), may_lookup(), may_open(), may_o_create(), may_create_in_sticky(), may_delete(), and may_create() helpers determine whether the caller is privileged enough to perform the associated operations. Let them handle idmapped mounts by mapping the inode or fsids according to the mount's user namespace. Afterwards the checks are identical to non-idmapped inodes. The patch takes care to retrieve the mount's user namespace right before performing permission checks and passing it down into the fileystem so the user namespace can't change in between by someone idmapping a mount that is currently not idmapped. 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/20210121131959.646623-13-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>
* stat: handle idmapped mountsChristian Brauner2021-01-2434-44/+52
| | | | | | | | | | | | | | | | | | The generic_fillattr() helper fills in the basic attributes associated with an inode. Enable it to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace before we store the uid and gid. 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/20210121131959.646623-12-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>
* commoncap: handle idmapped mountsChristian Brauner2021-01-242-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When interacting with user namespace and non-user namespace aware filesystem capabilities the vfs will perform various security checks to determine whether or not the filesystem capabilities can be used by the caller, whether they need to be removed and so on. The main infrastructure for this resides in the capability codepaths but they are called through the LSM security infrastructure even though they are not technically an LSM or optional. This extends the existing security hooks security_inode_removexattr(), security_inode_killpriv(), security_inode_getsecurity() to pass down the mount's user namespace and makes them aware of idmapped mounts. In order to actually get filesystem capabilities from disk the capability infrastructure exposes the get_vfs_caps_from_disk() helper. For user namespace aware filesystem capabilities a root uid is stored alongside the capabilities. In order to determine whether the caller can make use of the filesystem capability or whether it needs to be ignored it is translated according to the superblock's user namespace. If it can be translated to uid 0 according to that id mapping the caller can use the filesystem capabilities stored on disk. If we are accessing the inode that holds the filesystem capabilities through an idmapped mount we map the root uid according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts: reading filesystem caps from disk enforces that the root uid associated with the filesystem capability must have a mapping in the superblock's user namespace and that the caller is either in the same user namespace or is a descendant of the superblock's user namespace. For filesystems that are mountable inside user namespace the caller can just mount the filesystem and won't usually need to idmap it. If they do want to idmap it they can create an idmapped mount and mark it with a user namespace they created and which is thus a descendant of s_user_ns. For filesystems that are not mountable inside user namespaces the descendant rule is trivially true because the s_user_ns will be the initial 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/20210121131959.646623-11-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> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* xattr: handle idmapped mountsTycho Andersen2021-01-2411-95/+118
| | | | | | | | | | | | | | | | | | | | | | When interacting with extended attributes the vfs verifies that the caller is privileged over the inode with which the extended attribute is associated. For posix access and posix default extended attributes a uid or gid can be stored on-disk. Let the functions handle posix extended attributes on idmapped mounts. If the inode is accessed through an idmapped mount we need to map it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. This has no effect for e.g. security xattrs since they don't store uids or gids and don't perform permission checks on them like posix acls do. Link: https://lore.kernel.org/r/20210121131959.646623-10-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: Tycho Andersen <tycho@tycho.pizza> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* acl: handle idmapped mountsChristian Brauner2021-01-2463-64/+172
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* attr: handle idmapped mountsChristian Brauner2021-01-2453-129/+196
| | | | | | | | | | | | | | | | | | | | | | | | When file attributes are changed most filesystems rely on the setattr_prepare(), setattr_copy(), and notify_change() helpers for initialization and permission checking. Let them handle idmapped mounts. 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 mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Helpers that perform checks on the ia_uid and ia_gid fields in struct iattr assume that ia_uid and ia_gid are intended values and have already been mapped correctly at the userspace-kernelspace boundary as we already do today. 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/20210121131959.646623-8-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>
* inode: make init and permission helpers idmapped mount awareChristian Brauner2021-01-2448-81/+100
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* namei: make permission helpers idmapped mount awareChristian Brauner2021-01-2431-79/+150
| | | | | | | | | | | | | | | | | | | | | | 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>
* capability: handle idmapped mountsChristian Brauner2021-01-247-14/+19
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs: add file and path permissions helpersChristian Brauner2021-01-246-10/+10
| | | | | | | | | | | | | | | | | | Add two simple helpers to check permissions on a file and path respectively and convert over some callers. It simplifies quite a few codepaths and also reduces the churn in later patches quite a bit. Christoph also correctly points out that this makes codepaths (e.g. ioctls) way easier to follow that would otherwise have to do more complex argument passing than necessary. Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* mount: attach mappings to mountsChristian Brauner2021-01-241-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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. 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. Later patches enforce that once a mount has been idmapped it can't be remapped. This keeps permission checking and life-cycle management simple. Users wanting to change the idmapped can always create a new detached mount with a different idmapping. Add a new mnt_userns member to vfsmount and two simple helpers to retrieve the mnt_userns from vfsmounts and files. The idea to attach user namespaces to vfsmounts has been floated around in various forms at Linux Plumbers in ~2018 with the original idea tracing back to a discussion in 2017 at a conference in St. Petersburg between Christoph, Tycho, and myself. Link: https://lore.kernel.org/r/20210121131959.646623-2-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>
* Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds2021-01-171-2/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | Pull misc vfs fixes from Al Viro: "Several assorted fixes. I still think that audit ->d_name race is better fixed this way for the benefit of backports, with any possibly fancier variants done on top of it" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: dump_common_audit_data(): fix racy accesses to ->d_name iov_iter: fix the uaccess area in copy_compat_iovec_from_user umount(2): move the flag validity checks first
| * umount(2): move the flag validity checks firstAl Viro2021-01-041-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | Unfortunately, there's userland code that used to rely upon these checks being done before anything else to check for UMOUNT_NOFOLLOW support. That broke in 41525f56e256 ("fs: refactor ksys_umount"). Separate those from the rest of checks and move them to ksys_umount(); unlike everything else in there, this can be sanely done there. Reported-by: Sargun Dhillon <sargun@sargun.me> Fixes: 41525f56e256 ("fs: refactor ksys_umount") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'io_uring-5.11-2021-01-16' of git://git.kernel.dk/linux-blockLinus Torvalds2021-01-161-5/+41
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull io_uring fixes from Jens Axboe: "We still have a pending fix for a cancelation issue, but it's still being investigated. In the meantime: - Dead mm handling fix (Pavel) - SQPOLL setup error handling (Pavel) - Flush timeout sequence fix (Marcelo) - Missing finish_wait() for one exit case" * tag 'io_uring-5.11-2021-01-16' of git://git.kernel.dk/linux-block: io_uring: ensure finish_wait() is always called in __io_uring_task_cancel() io_uring: flush timeouts that should already have expired io_uring: do sqo disable on install_fd error io_uring: fix null-deref in io_disable_sqo_submit io_uring: don't take files/mm for a dead task io_uring: drop mm and files after task_work_run
| * | io_uring: ensure finish_wait() is always called in __io_uring_task_cancel()Jens Axboe2021-01-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we enter with requests pending and performm cancelations, we'll have a different inflight count before and after calling prepare_to_wait(). This causes the loop to restart. If we actually ended up canceling everything, or everything completed in-between, then we'll break out of the loop without calling finish_wait() on the waitqueue. This can trigger a warning on exit_signals(), as we leave the task state in TASK_UNINTERRUPTIBLE. Put a finish_wait() after the loop to catch that case. Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | io_uring: flush timeouts that should already have expiredMarcelo Diop-Gonzalez2021-01-151-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now io_flush_timeouts() checks if the current number of events is equal to ->timeout.target_seq, but this will miss some timeouts if there have been more than 1 event added since the last time they were flushed (possible in io_submit_flush_completions(), for example). Fix it by recording the last sequence at which timeouts were flushed so that the number of events seen can be compared to the number of events needed without overflow. Signed-off-by: Marcelo Diop-Gonzalez <marcelo827@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | io_uring: do sqo disable on install_fd errorPavel Begunkov2021-01-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: CPU: 0 PID: 8494 at fs/io_uring.c:8717 io_ring_ctx_wait_and_kill+0x4f2/0x600 fs/io_uring.c:8717 Call Trace: io_uring_release+0x3e/0x50 fs/io_uring.c:8759 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 failed io_uring_install_fd() is a special case, we don't do io_ring_ctx_wait_and_kill() directly but defer it to fput, though still need to io_disable_sqo_submit() before. note: it doesn't fix any real problem, just a warning. That's because sqring won't be available to the userspace in this case and so SQPOLL won't submit anything. Reported-by: syzbot+9c9c35374c0ecac06516@syzkaller.appspotmail.com Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | io_uring: fix null-deref in io_disable_sqo_submitPavel Begunkov2021-01-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | general protection fault, probably for non-canonical address 0xdffffc0000000022: 0000 [#1] KASAN: null-ptr-deref in range [0x0000000000000110-0x0000000000000117] RIP: 0010:io_ring_set_wakeup_flag fs/io_uring.c:6929 [inline] RIP: 0010:io_disable_sqo_submit+0xdb/0x130 fs/io_uring.c:8891 Call Trace: io_uring_create fs/io_uring.c:9711 [inline] io_uring_setup+0x12b1/0x38e0 fs/io_uring.c:9739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 io_disable_sqo_submit() might be called before user rings were allocated, don't do io_ring_set_wakeup_flag() in those cases. Reported-by: syzbot+ab412638aeb652ded540@syzkaller.appspotmail.com Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | io_uring: don't take files/mm for a dead taskPavel Begunkov2021-01-111-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In rare cases a task may be exiting while io_ring_exit_work() trying to cancel/wait its requests. It's ok for __io_sq_thread_acquire_mm() because of SQPOLL check, but is not for __io_sq_thread_acquire_files(). Play safe and fail for both of them. Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | io_uring: drop mm and files after task_work_runPavel Begunkov2021-01-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __io_req_task_submit() run by task_work can set mm and files, but io_sq_thread() in some cases, and because __io_sq_thread_acquire_mm() and __io_sq_thread_acquire_files() do a simple current->mm/files check it may end up submitting IO with mm/files of another task. We also need to drop it after in the end to drop potentially grabbed references to them. Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | | mm: don't play games with pinned pages in clear_page_refsLinus Torvalds2021-01-161-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Turning a pinned page read-only breaks the pinning after COW. Don't do it. The whole "track page soft dirty" state doesn't work with pinned pages anyway, since the page might be dirtied by the pinning entity without ever being noticed in the page tables. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: fix clear_refs_write lockingLinus Torvalds2021-01-161-23/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Turning page table entries read-only requires the mmap_sem held for writing. So stop doing the odd games with turning things from read locks to write locks and back. Just get the write lock. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds2021-01-1510-129/+186
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "A number of bug fixes for ext4: - Fix for the new fast_commit feature - Fix some error handling codepaths in whiteout handling and mountpoint sampling - Fix how we write ext4_error information so it goes through the journal when journalling is active, to avoid races that can lead to lost error information, superblock checksum failures, or DIF/DIX features" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: remove expensive flush on fast commit ext4: fix bug for rename with RENAME_WHITEOUT ext4: fix wrong list_splice in ext4_fc_cleanup ext4: use IS_ERR instead of IS_ERR_OR_NULL and set inode null when IS_ERR ext4: don't leak old mountpoint samples ext4: drop ext4_handle_dirty_super() ext4: fix superblock checksum failure when setting password salt ext4: use sbi instead of EXT4_SB(sb) in ext4_update_super() ext4: save error info to sb through journal if available ext4: protect superblock modifications with a buffer lock ext4: drop sync argument of ext4_commit_super() ext4: combine ext4_handle_error() and save_error_info()
| * | | ext4: remove expensive flush on fast commitDaejun Park2021-01-151-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the fast commit, it adds REQ_FUA and REQ_PREFLUSH on each fast commit block when barrier is enabled. However, in recovery phase, ext4 compares CRC value in the tail. So it is sufficient to add REQ_FUA and REQ_PREFLUSH on the block that has tail. Signed-off-by: Daejun Park <daejun7.park@samsung.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20210106013242epcms2p5b6b4ed8ca86f29456fdf56aa580e74b4@epcms2p5 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: fix bug for rename with RENAME_WHITEOUTyangerkun2021-01-151-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We got a "deleted inode referenced" warning cross our fsstress test. The bug can be reproduced easily with following steps: cd /dev/shm mkdir test/ fallocate -l 128M img mkfs.ext4 -b 1024 img mount img test/ dd if=/dev/zero of=test/foo bs=1M count=128 mkdir test/dir/ && cd test/dir/ for ((i=0;i<1000;i++)); do touch file$i; done # consume all block cd ~ && renameat2(AT_FDCWD, /dev/shm/test/dir/file1, AT_FDCWD, /dev/shm/test/dir/dst_file, RENAME_WHITEOUT) # ext4_add_entry in ext4_rename will return ENOSPC!! cd /dev/shm/ && umount test/ && mount img test/ && ls -li test/dir/file1 We will get the output: "ls: cannot access 'test/dir/file1': Structure needs cleaning" and the dmesg show: "EXT4-fs error (device loop0): ext4_lookup:1626: inode #2049: comm ls: deleted inode referenced: 139" ext4_rename will create a special inode for whiteout and use this 'ino' to replace the source file's dir entry 'ino'. Once error happens latter(the error above was the ENOSPC return from ext4_add_entry in ext4_rename since all space has been consumed), the cleanup do drop the nlink for whiteout, but forget to restore 'ino' with source file. This will trigger the bug describle as above. Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org Fixes: cd808deced43 ("ext4: support RENAME_WHITEOUT") Link: https://lore.kernel.org/r/20210105062857.3566-1-yangerkun@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: fix wrong list_splice in ext4_fc_cleanupDaejun Park2021-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After full/fast commit, entries in staging queue are promoted to main queue. In ext4_fs_cleanup function, it splice to staging queue to staging queue. Fixes: aa75f4d3daaeb ("ext4: main fast-commit commit path") Signed-off-by: Daejun Park <daejun7.park@samsung.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201230094851epcms2p6eeead8cc984379b37b2efd21af90fd1a@epcms2p6 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
| * | | ext4: use IS_ERR instead of IS_ERR_OR_NULL and set inode null when IS_ERRYi Li2021-01-151-11/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1: ext4_iget/ext4_find_extent never returns NULL, use IS_ERR instead of IS_ERR_OR_NULL to fix this. 2: ext4_fc_replay_inode should set the inode to NULL when IS_ERR. and go to call iput properly. Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Yi Li <yili@winhong.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201230033827.3996064-1-yili@winhong.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
| * | | ext4: don't leak old mountpoint samplesTheodore Ts'o2020-12-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the first file is opened, ext4 samples the mountpoint of the filesystem in 64 bytes of the super block. It does so using strlcpy(), this means that the remaining bytes in the super block string buffer are untouched. If the mount point before had a longer path than the current one, it can be reconstructed. Consider the case where the fs was mounted to "/media/johnjdeveloper" and later to "/". The super block buffer then contains "/\x00edia/johnjdeveloper". This case was seen in the wild and caused confusion how the name of a developer ands up on the super block of a filesystem used in production... Fix this by using strncpy() instead of strlcpy(). The superblock field is defined to be a fixed-size char array, and it is already marked using __nonstring in fs/ext4/ext4.h. The consumer of the field in e2fsprogs already assumes that in the case of a 64+ byte mount path, that s_last_mounted will not be NUL terminated. Link: https://lore.kernel.org/r/X9ujIOJG/HqMr88R@mit.edu Reported-by: Richard Weinberger <richard@nod.at> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
| * | | ext4: drop ext4_handle_dirty_super()Jan Kara2020-12-227-30/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The wrapper is now useless since it does what ext4_handle_dirty_metadata() does. Just remove it. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-9-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: fix superblock checksum failure when setting password saltJan Kara2020-12-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When setting password salt in the superblock, we forget to recompute the superblock checksum so it will not match until the next superblock modification which recomputes the checksum. Fix it. CC: Michael Halcrow <mhalcrow@google.com> Reported-by: Andreas Dilger <adilger@dilger.ca> Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-8-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: use sbi instead of EXT4_SB(sb) in ext4_update_super()Jan Kara2020-12-221-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No behavioral change. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-6-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: save error info to sb through journal if availableJan Kara2020-12-221-26/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If journalling is still working at the moment we get to writing error information to the superblock we cannot write directly to the superblock as such write could race with journalled update of the superblock and cause journal checksum failures, writing inconsistent information to the journal or other problems. We cannot journal the superblock directly from the error handling functions as we are running in uncertain context and could deadlock so just punt journalled superblock update to a workqueue. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-5-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: protect superblock modifications with a buffer lockJan Kara2020-12-227-2/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Protect all superblock modifications (including checksum computation) with a superblock buffer lock. That way we are sure computed checksum matches current superblock contents (a mismatch could cause checksum failures in nojournal mode or if an unjournalled superblock update races with a journalled one). Also we avoid modifying superblock contents while it is being written out (which can cause DIF/DIX failures if we are running in nojournal mode). Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-4-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: drop sync argument of ext4_commit_super()Jan Kara2020-12-221-25/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Everybody passes 1 as sync argument of ext4_commit_super(). Just drop it. Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-3-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | ext4: combine ext4_handle_error() and save_error_info()Jan Kara2020-12-221-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | save_error_info() is always called together with ext4_handle_error(). Combine them into a single call and move unconditional bits out of save_error_info() into ext4_handle_error(). Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-2-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | | | Merge tag '5.11-rc3-smb3' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds2021-01-155-7/+6
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cifs fixes from Steve French: "Two small cifs fixes for stable (including an important handle leak fix) and three small cleanup patches" * tag '5.11-rc3-smb3' of git://git.samba.org/sfrench/cifs-2.6: cifs: style: replace one-element array with flexible-array cifs: connect: style: Simplify bool comparison fs: cifs: remove unneeded variable in smb3_fs_context_dup cifs: fix interrupted close commands cifs: check pointer before freeing
| * | | | cifs: style: replace one-element array with flexible-arrayYANG LI2021-01-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use "flexible array members"[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/ deprecated.html#zero-length-and-one-element-arrays Signed-off-by: YANG LI <abaci-bugfix@linux.alibaba.com> Reported-by: Abaci <abaci@linux.alibaba.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | | | cifs: connect: style: Simplify bool comparisonYANG LI2021-01-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following coccicheck warning: ./fs/cifs/connect.c:3740:6-21: WARNING: Comparison of 0/1 to bool variable Signed-off-by: YANG LI <abaci-bugfix@linux.alibaba.com> Reported-by: Abaci Robot<abaci@linux.alibaba.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | | | fs: cifs: remove unneeded variable in smb3_fs_context_dupMenglong Dong2021-01-131-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'rc' in smb3_fs_context_dup is not used and can be removed. Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>