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2017-07-07dentry name snapshotsAl Viro
take_dentry_name_snapshot() takes a safe snapshot of dentry name; if the name is a short one, it gets copied into caller-supplied structure, otherwise an extra reference to external name is grabbed (those are never modified). In either case the pointer to stable string is stored into the same structure. dentry must be held by the caller of take_dentry_name_snapshot(), but may be freely dropped afterwards - the snapshot will stay until destroyed by release_dentry_name_snapshot(). Intended use: struct name_snapshot s; take_dentry_name_snapshot(&s, dentry); ... access s.name ... release_dentry_name_snapshot(&s); Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name to pass down with event. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-25fanotify: don't expose EOPENSTALE to userspaceAmir Goldstein
When delivering an event to userspace for a file on an NFS share, if the file is deleted on server side before user reads the event, user will not get the event. If the event queue contained several events, the stale event is quietly dropped and read() returns to user with events read so far in the buffer. If the event queue contains a single stale event or if the stale event is a permission event, read() returns to user with the kernel internal error code 518 (EOPENSTALE), which is not a POSIX error code. Check the internal return value -EOPENSTALE in fanotify_read(), just the same as it is checked in path_openat() and drop the event in the cases that it is not already dropped. This is a reproducer from Marko Rauhamaa: Just take the example program listed under "man fanotify" ("fantest") and follow these steps: ============================================================== NFS Server NFS Client(1) NFS Client(2) ============================================================== # echo foo >/nfsshare/bar.txt # cat /nfsshare/bar.txt foo # ./fantest /nfsshare Press enter key to terminate. Listening for events. # rm -f /nfsshare/bar.txt # cat /nfsshare/bar.txt read: Unknown error 518 cat: /nfsshare/bar.txt: Operation not permitted ============================================================== where NFS Client (1) and (2) are two terminal sessions on a single NFS Client machine. Reported-by: Marko Rauhamaa <marko.rauhamaa@f-secure.com> Tested-by: Marko Rauhamaa <marko.rauhamaa@f-secure.com> Cc: <linux-api@vger.kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-24fsnotify: remove a stray unlockDan Carpenter
We recently shifted this code around, so we're no longer holding the lock on this path. Fixes: 755b5bc681eb ("fsnotify: Remove indirection from mark list addition") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move ->free_mark callback to fsnotify_opsJan Kara
Pointer to ->free_mark callback unnecessarily occupies one long in each fsnotify_mark although they are the same for all marks from one notification group. Move the callback pointer to fsnotify_ops. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Add group pointer in fsnotify_init_mark()Jan Kara
Currently we initialize mark->group only in fsnotify_add_mark_lock(). However we will need to access fsnotify_ops of corresponding group from fsnotify_put_mark() so we need mark->group initialized earlier. Do that in fsnotify_init_mark() which has a consequence that once fsnotify_init_mark() is called on a mark, the mark has to be destroyed by fsnotify_put_mark(). Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Drop inode_mark.cJan Kara
inode_mark.c now contains only a single function. Move it to fs/notify/fsnotify.c and remove inode_mark.c. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()Jan Kara
These are very thin wrappers, just remove them. Drop fs/notify/vfsmount_mark.c as it is empty now. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_detach_group_marks()Jan Kara
The function is already mostly contained in what fsnotify_clear_marks_by_group() does. Just update that function to not select marks when all of them should be destroyed and remove fsnotify_detach_group_marks(). Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Rename fsnotify_clear_marks_by_group_flags()Jan Kara
The _flags() suffix in the function name was more confusing than explaining so just remove it. Also rename the argument from 'flags' to 'type' to better explain what the function expects. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Suggested-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group()Jan Kara
Inline these helpers as they are very thin. We still keep them as we don't want to expose details about how list type is determined. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_recalc_{inode|vfsmount}_mask()Jan Kara
These helpers are just very thin wrappers now. Remove them. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_set_mark_{,ignored_}mask_locked()Jan Kara
These helpers are now only a simple assignment and just obfuscate what is going on. Remove them. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fanotify: Release SRCU lock when waiting for userspace responseJan Kara
When userspace task processing fanotify permission events screws up and does not respond, fsnotify_mark_srcu SRCU is held indefinitely which causes further hangs in the whole notification subsystem. Although we cannot easily solve the problem of operations blocked waiting for response from userspace, we can at least somewhat localize the damage by dropping SRCU lock before waiting for userspace response and reacquiring it when userspace responds. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Pass fsnotify_iter_info into handle_event handlerJan Kara
Pass fsnotify_iter_info into ->handle_event() handler so that it can release and reacquire SRCU lock via fsnotify_prepare_user_wait() and fsnotify_finish_user_wait() functions. These functions also make sure current marks are appropriately pinned so that iteration protected by srcu in fsnotify() stays safe. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Provide framework for dropping SRCU lock in ->handle_eventJan Kara
fanotify wants to drop fsnotify_mark_srcu lock when waiting for response from userspace so that the whole notification subsystem is not blocked during that time. This patch provides a framework for safely getting mark reference for a mark found in the object list which pins the mark in that list. We can then drop fsnotify_mark_srcu, wait for userspace response and then safely continue iteration of the object list once we reaquire fsnotify_mark_srcu. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove special handling of mark destruction on group shutdownJan Kara
Currently we queue all marks for destruction on group shutdown and then destroy them from fsnotify_destroy_group() instead from a worker thread which is the usual path. However worker can already be processing some list of marks to destroy so this does not make 100% all marks are really destroyed by the time group is shut down. This isn't a big problem as each mark holds group reference and thus group stays partially alive until all marks are really freed but there's no point in complicating our lives - just wait for the delayed work to be finished instead. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Detach mark from object list when last reference is droppedJan Kara
Instead of removing mark from object list from fsnotify_detach_mark(), remove the mark when last reference to the mark is dropped. This will allow fanotify to wait for userspace response to event without having to hold onto fsnotify_mark_srcu. To avoid pinning inodes by elevated refcount (and thus e.g. delaying file deletion) while someone holds mark reference, we detach connector from the object also from fsnotify_destroy_marks() and not only after removing last mark from the list as it was now. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move queueing of mark for destruction into fsnotify_put_mark()Jan Kara
Currently we queue mark into a list of marks for destruction in __fsnotify_free_mark() and keep the last mark reference dangling. After the worker waits for SRCU period, it drops the last reference to the mark which frees it. This scheme has the disadvantage that if we hold reference to a mark and drop and reacquire SRCU lock, the mark can get freed immediately which is slightly inconvenient and we will need to avoid this in the future. Move to a scheme where queueing of mark into a list of marks for destruction happens when the last reference to the mark is dropped. Also drop reference to the mark held by group list already when mark is removed from that list instead of dropping it only from the destruction worker. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10inotify: Do not drop mark reference under idr_lockJan Kara
Dropping mark reference can result in mark being freed. Although it should not happen in inotify_remove_from_idr() since caller should hold another reference, just don't risk lock up just after WARN_ON unnecessarily. Also fold do_inotify_remove_from_idr() into the single callsite as that function really is just two lines of real code. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Free fsnotify_mark_connector when there is no mark attachedJan Kara
Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Lock object list with connector lockJan Kara
So far list of marks attached to an object (inode / vfsmount) was protected by i_lock or mnt_root->d_lock. This dictates that the list must be empty before the object can be destroyed although the list is now anchored in the fsnotify_mark_connector structure. Protect the list by a spinlock in the fsnotify_mark_connector structure to decouple lifetime of a list of marks from a lifetime of the object. This also simplifies the code quite a bit since we don't have to differentiate between inode and vfsmount lists in quite a few places anymore. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove useless list deletion and commentJan Kara
After removing all the indirection it is clear that hlist_del_init_rcu(&mark->obj_list); in fsnotify_destroy_marks() is not needed as the mark gets removed from the list shortly afterwards in fsnotify_destroy_mark() -> fsnotify_detach_mark() -> fsnotify_detach_from_object(). Also there is no problem with mark being visible on object list while we call fsnotify_destroy_mark() as parallel destruction of marks from several places is properly handled (as mentioned in the comment in fsnotify_destroy_marks(). So just remove the list removal and also the stale comment. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Avoid double locking in fsnotify_detach_from_object()Jan Kara
We lock object list lock in fsnotify_detach_from_object() twice - once to detach mark and second time to recalculate mask. That is unnecessary and later it will become problematic as we will free the connector as soon as there is no mark in it. So move recalculation of fsnotify mask into the same critical section that is detaching mark. This also removes recalculation of child dentry flags from fsnotify_detach_from_object(). That is however fine. Those marks will get recalculated once some event happens on a child. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove indirection from fsnotify_detach_mark()Jan Kara
fsnotify_detach_mark() calls fsnotify_destroy_inode_mark() or fsnotify_destroy_vfsmount_mark() to remove mark from object list. These two functions are however very similar and differ only in the lock they use to protect the object list of marks. Simplify the code by removing the indirection and removing mark from the object list in a common function. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Determine lock in fsnotify_destroy_marks()Jan Kara
Instead of passing spinlock into fsnotify_destroy_marks() determine it directly in that function from the connector type. This will reduce code churn when changing lock protecting list of marks. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move locking into fsnotify_find_mark()Jan Kara
Move locking of a mark list into fsnotify_find_mark(). This reduces code churn in the following patch changing lock protecting the list. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move locking into fsnotify_recalc_mask()Jan Kara
Move locking of locks protecting a list of marks into fsnotify_recalc_mask(). This reduces code churn in the following patch which changes the lock protecting the list of marks. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move fsnotify_destroy_marks()Jan Kara
Move fsnotify_destroy_marks() to be later in the fs/notify/mark.c. It will need some functions that are declared after its current declaration. No functional change. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove indirection from mark list additionJan Kara
Adding notification mark to object list has been currently done through fsnotify_add_{inode|vfsmount}_mark() helpers from fsnotify_add_mark_locked() which call fsnotify_add_mark_list(). Remove this unnecessary indirection to simplify the code. Pushing all the locking to fsnotify_add_mark_list() also allows us to allocate the connector structure with GFP_KERNEL mode. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Make fsnotify_mark_connector hold inode referenceJan Kara
Currently inode reference is held by fsnotify marks. Change the rules so that inode reference is held by fsnotify_mark_connector structure whenever the list is non-empty. This simplifies the code and is more logical. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move object pointer to fsnotify_mark_connectorJan Kara
Move pointer to inode / vfsmount from mark itself to the fsnotify_mark_connector structure. This is another step on the path towards decoupling inode / vfsmount lifetime from notification mark lifetime. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move mark list head from object into dedicated structureJan Kara
Currently notification marks are attached to object (inode or vfsmnt) by a hlist_head in the object. The list is also protected by a spinlock in the object. So while there is any mark attached to the list of marks, the object must be pinned in memory (and thus e.g. last iput() deleting inode cannot happen). Also for list iteration in fsnotify() to work, we must hold fsnotify_mark_srcu lock so that mark itself and mark->obj_list.next cannot get freed. Thus we are required to wait for response to fanotify events from userspace process with fsnotify_mark_srcu lock held. That causes issues when userspace process is buggy and does not reply to some event - basically the whole notification subsystem gets eventually stuck. So to be able to drop fsnotify_mark_srcu lock while waiting for response, we have to pin the mark in memory and make sure it stays in the object list (as removing the mark waiting for response could lead to lost notification events for groups later in the list). However we don't want inode reclaim to block on such mark as that would lead to system just locking up elsewhere. This commit is the first in the series that paves way towards solving these conflicting lifetime needs. Instead of anchoring the list of marks directly in the object, we anchor it in a dedicated structure (fsnotify_mark_connector) and just point to that structure from the object. The following commits will also add spinlock protecting the list and object pointer to the structure. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Update commentsJan Kara
Add a comment that lifetime of a notification mark is protected by SRCU and remove a comment about clearing of marks attached to the inode. It is stale and more uptodate version is at fsnotify_destroy_marks() which is the function handling this case. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-03fanotify: Move recalculation of inode / vfsmount mask under mark_mutexJan Kara
Move recalculation of inode / vfsmount notification mask under group->mark_mutex of the mark which was modified. These are the only places where mask recalculation happens without mark being protected from detaching from inode / vfsmount which will cause issues with the following patches. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-03inotify: Remove inode pointers from debug messagesJan Kara
Printing inode pointers in warnings has dubious value and with future changes we won't be able to easily get them without either locking or chances we oops along the way. So just remove inode pointers from the warning messages. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-03fsnotify: Remove unnecessary tests when showing fdinfoJan Kara
show_fdinfo() iterates group's list of marks. All marks found there are guaranteed to be alive and they stay so until we release group->mark_mutex. So remove uncecessary tests whether mark is alive. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. 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>
2017-03-02sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar
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>
2017-02-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits
2017-02-21Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull UDF fixes and cleanups from Jan Kara: "Several small UDF fixes and cleanups and a small cleanup of fanotify code" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fanotify: simplify the code of fanotify_merge udf: simplify udf_ioctl() udf: fix ioctl errors udf: allow implicit blocksize specification during mount udf: check partition reference in udf_read_inode() udf: atomically read inode size udf: merge module informations in super.c udf: remove next_epos from udf_update_extent_cache() udf: Factor out trimming of crtime udf: remove empty condition udf: remove unneeded line break udf: merge bh free udf: use pointer for kernel_long_ad argument udf: use __packed instead of __attribute__ ((packed)) udf: Make stat on symlink report symlink length as st_size fs/udf: make #ifdef UDF_PREALLOCATE unconditional fs: udf: Replace CURRENT_TIME with current_time()
2017-02-09fanotify: simplify the code of fanotify_mergeKinglong Mee
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-01-24inotify: Convert to using per-namespace limitsNikolay Borisov
This patchset converts inotify to using the newly introduced per-userns sysctl infrastructure. Currently the inotify instances/watches are being accounted in the user_struct structure. This means that in setups where multiple users in unprivileged containers map to the same underlying real user (i.e. pointing to the same user_struct) the inotify limits are going to be shared as well, allowing one user(or application) to exhaust all others limits. Fix this by switching the inotify sysctls to using the per-namespace/per-user limits. This will allow the server admin to set sensible global limits, which can further be tuned inside every individual user namespace. Additionally, in order to preserve the sysctl ABI make the existing inotify instances/watches sysctls modify the values of the initial user namespace. Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-01-05Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit fixes from Paul Moore: "Two small fixes relating to audit's use of fsnotify. The first patch plugs a leak and the second fixes some lock shenanigans. The patches are small and I banged on this for an afternoon with our testsuite and didn't see anything odd" * 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit: audit: Fix sleep in atomic fsnotify: Remove fsnotify_duplicate_mark()
2016-12-23fsnotify: Remove fsnotify_duplicate_mark()Jan Kara
There are only two calls sites of fsnotify_duplicate_mark(). Those are in kernel/audit_tree.c and both are bogus. Vfsmount pointer is unused for audit tree, inode pointer and group gets set in fsnotify_add_mark_locked() later anyway, mask and free_mark are already set in alloc_chunk(). In fact, calling fsnotify_duplicate_mark() is actively harmful because following fsnotify_add_mark_locked() will leak group reference by overwriting the group pointer. So just remove the two calls to fsnotify_duplicate_mark() and the function. Signed-off-by: Jan Kara <jack@suse.cz> [PM: line wrapping to fit in 80 chars] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-19Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota, fsnotify and ext2 updates from Jan Kara: "Changes to locking of some quota operations from dedicated quota mutex to s_umount semaphore, a fsnotify fix and a simple ext2 fix" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: quota: Fix bogus warning in dquot_disable() fsnotify: Fix possible use-after-free in inode iteration on umount ext2: reject inodes with negative size quota: Remove dqonoff_mutex ocfs2: Use s_umount for quota recovery protection quota: Remove dqonoff_mutex from dquot_scan_active() ocfs2: Protect periodic quota syncing with s_umount semaphore quota: Use s_umount protection for quota operations quota: Hold s_umount in exclusive mode when enabling / disabling quotas fs: Provide function to get superblock with exclusive s_umount
2016-12-13fsnotify: Fix possible use-after-free in inode iteration on umountJan Kara
fsnotify_unmount_inodes() plays complex tricks to pin next inode in the sb->s_inodes list when iterating over all inodes. Furthermore the code has a bug that if the current inode is the last on i_sb_list that does not have e.g. I_FREEING set, then we leave next_i pointing to inode which may get removed from the i_sb_list once we drop s_inode_list_lock thus resulting in use-after-free issues (usually manifesting as infinite looping in fsnotify_unmount_inodes()). Fix the problem by keeping current inode pinned somewhat longer. Then we can make the code much simpler and standard. CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz>
2016-12-05constify fsnotify_parent()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-05fsnotify(): constify 'data'Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-05fsnotify: constify 'data' passed to ->handle_event()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07fsnotify: clean up spinlock assertionsJan Kara
Use assert_spin_locked() macro instead of hand-made BUG_ON statements. Link: http://lkml.kernel.org/r/1474537439-18919-1-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>