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2015-03-13fanotify: fix event filtering with FAN_ONDIR setSuzuki K. Poulose
With FAN_ONDIR set, the user can end up getting events, which it hasn't marked. This was revealed with fanotify04 testcase failure on Linux-4.0-rc1, and is a regression from 3.19, revealed with 66ba93c0d7fe6 ("fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask"). # /opt/ltp/testcases/bin/fanotify04 [ ... ] fanotify04 7 TPASS : event generated properly for type 100000 fanotify04 8 TFAIL : fanotify04.c:147: got unexpected event 30 fanotify04 9 TPASS : No event as expected The testcase sets the adds the following marks : FAN_OPEN | FAN_ONDIR for a fanotify on a dir. Then does an open(), followed by close() of the directory and expects to see an event FAN_OPEN(0x20). However, the fanotify returns (FAN_OPEN|FAN_CLOSE_NOWRITE(0x10)). This happens due to the flaw in the check for event_mask in fanotify_should_send_event() which does: if (event_mask & marks_mask & ~marks_ignored_mask) return true; where, event_mask == (FAN_ONDIR | FAN_CLOSE_NOWRITE), marks_mask == (FAN_ONDIR | FAN_OPEN), marks_ignored_mask == 0 Fix this by masking the outgoing events to the user, as we already take care of FAN_ONDIR and FAN_EVENT_ON_CHILD. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-22fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversionsDavid Howells
Fanotify probably doesn't want to watch autodirs so make it use d_can_lookup() rather than d_is_dir() when checking a dir watch and give an error on fake directories. 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 Howells
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>
2015-02-10fanotify: don't set FAN_ONDIR implicitly on a marks ignored maskLino Sanfilippo
Currently FAN_ONDIR is always set on a mark's ignored mask when the event mask is extended without FAN_MARK_ONDIR being set. This may result in events for directories being ignored unexpectedly for call sequences like fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir"); fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir"); Also FAN_MARK_ONDIR is only honored when adding events to a mark's mask, but not for event removal. Fix both issues by not setting FAN_ONDIR implicitly on the ignore mask any more. Instead treat FAN_ONDIR as any other event flag and require FAN_MARK_ONDIR to be set by the user for both event mask and ignore mask. Furthermore take FAN_MARK_ONDIR into account when set for event removal. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10fanotify: don't recalculate a marks mask if only the ignored mask changedLino Sanfilippo
If removing bits from a mark's ignored mask, the concerning inodes/vfsmounts mask is not affected. So don't recalculate it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10fanotify: only destroy mark when both mask and ignored_mask are clearedLino Sanfilippo
In fanotify_mark_remove_from_mask() a mark is destroyed if only one of both bitmasks (mask or ignored_mask) of a mark is cleared. However the other mask may still be set and contain information that should not be lost. So only destroy a mark if both masks are cleared. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-09sched, fanotify: Deal with nested sleepsPeter Zijlstra
As per e23738a7300a ("sched, inotify: Deal with nested sleeps"). fanotify_read is a wait loop with sleeps in. Wait loops rely on task_struct::state and sleeps do too, since that's the only means of actually sleeping. Therefore the nested sleeps destroy the wait loop state and the wait loop breaks the sleep functions that assume TASK_RUNNING (mutex_lock). Fix this by using the new woken_wake_function and wait_woken() stuff, which registers wakeups in wait and thereby allows shrinking the task_state::state changes to the actual sleep part. Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Takashi Iwai <tiwai@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Paris <eparis@redhat.com> Link: http://lkml.kernel.org/r/20141216152838.GZ3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-10fanotify: enable close-on-exec on events' fd when requested in fanotify_init()Yann Droneaud
According to commit 80af258867648 ("fanotify: groups can specify their f_flags for new fd"), file descriptors created as part of file access notification events inherit flags from the event_f_flags argument passed to syscall fanotify_init(2)[1]. Unfortunately O_CLOEXEC is currently silently ignored. Indeed, event_f_flags are only given to dentry_open(), which only seems to care about O_ACCMODE and O_PATH in do_dentry_open(), O_DIRECT in open_check_o_direct() and O_LARGEFILE in generic_file_open(). It's a pity, since, according to some lookup on various search engines and http://codesearch.debian.net/, there's already some userspace code which use O_CLOEXEC: - in systemd's readahead[2]: fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME); - in clsync[3]: #define FANOTIFY_EVFLAGS (O_LARGEFILE|O_RDONLY|O_CLOEXEC) int fanotify_d = fanotify_init(FANOTIFY_FLAGS, FANOTIFY_EVFLAGS); - in examples [4] from "Filesystem monitoring in the Linux kernel" article[5] by Aleksander Morgado: if ((fanotify_fd = fanotify_init (FAN_CLOEXEC, O_RDONLY | O_CLOEXEC | O_LARGEFILE)) < 0) Additionally, since commit 48149e9d3a7e ("fanotify: check file flags passed in fanotify_init"). having O_CLOEXEC as part of fanotify_init() second argument is expressly allowed. So it seems expected to set close-on-exec flag on the file descriptors if userspace is allowed to request it with O_CLOEXEC. But Andrew Morton raised[6] the concern that enabling now close-on-exec might break existing applications which ask for O_CLOEXEC but expect the file descriptor to be inherited across exec(). In the other hand, as reported by Mihai Dontu[7] close-on-exec on the file descriptor returned as part of file access notify can break applications due to deadlock. So close-on-exec is needed for most applications. More, applications asking for close-on-exec are likely expecting it to be enabled, relying on O_CLOEXEC being effective. If not, it might weaken their security, as noted by Jan Kara[8]. So this patch replaces call to macro get_unused_fd() by a call to function get_unused_fd_flags() with event_f_flags value as argument. This way O_CLOEXEC flag in the second argument of fanotify_init(2) syscall is interpreted and close-on-exec get enabled when requested. [1] http://man7.org/linux/man-pages/man2/fanotify_init.2.html [2] http://cgit.freedesktop.org/systemd/systemd/tree/src/readahead/readahead-collect.c?id=v208#n294 [3] https://github.com/xaionaro/clsync/blob/v0.2.1/sync.c#L1631 https://github.com/xaionaro/clsync/blob/v0.2.1/configuration.h#L38 [4] http://www.lanedo.com/~aleksander/fanotify/fanotify-example.c [5] http://www.lanedo.com/2013/filesystem-monitoring-linux-kernel/ [6] http://lkml.kernel.org/r/20141001153621.65e9258e65a6167bf2e4cb50@linux-foundation.org [7] http://lkml.kernel.org/r/20141002095046.3715eb69@mdontu-l [8] http://lkml.kernel.org/r/20141002104410.GB19748@quack.suse.cz Link: http://lkml.kernel.org/r/cover.1411562410.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed by: Heinrich Schuchardt <xypron.glpk@gmx.de> Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Mihai Don\u021bu <mihai.dontu@gmail.com> Cc: Pádraig Brady <P@draigBrady.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Jan Kara <jack@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Michael Kerrisk-manpages <mtk.manpages@gmail.com> Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Richard Guy Briggs <rgb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07fanotify: fix double free of pending permission eventsJan Kara
Commit 85816794240b ("fanotify: Fix use after free for permission events") introduced a double free issue for permission events which are pending in group's notification queue while group is being destroyed. These events are freed from fanotify_handle_event() but they are not removed from groups notification queue and thus they get freed again from fsnotify_flush_notify(). Fix the problem by removing permission events from notification queue before freeing them if we skip processing access response. Also expand comments in fanotify_release() to explain group shutdown in detail. Fixes: 85816794240b9659e66e4d9b0df7c6e814e5f603 Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Douglas Leeder <douglas.leeder@sophos.com> Tested-by: Douglas Leeder <douglas.leeder@sophos.com> Reported-by: Heinrich Schuchard <xypron.glpk@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07fsnotify: rename event handling functionsJan Kara
Rename fsnotify_add_notify_event() to fsnotify_add_event() since the "notify" part is duplicit. Rename fsnotify_remove_notify_event() and fsnotify_peek_notify_event() to fsnotify_remove_first_event() and fsnotify_peek_first_event() respectively since "notify" part is duplicit and they really look at the first event in the queue. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fanotify: check file flags passed in fanotify_initHeinrich Schuchardt
Without this patch fanotify_init does not validate the value passed in event_f_flags. When a fanotify event is read from the fanotify file descriptor a new file descriptor is created where file.f_flags = event_f_flags. Internal and external open flags are stored together in field f_flags of struct file. Hence, an application might create file descriptors with internal flags like FMODE_EXEC, FMODE_NOCMTIME set. Jan Kara and Eric Paris both aggreed that this is a bug and the value of event_f_flags should be checked: https://lkml.org/lkml/2014/4/29/522 https://lkml.org/lkml/2014/4/29/539 This updated patch version considers the comments by Michael Kerrisk in https://lkml.org/lkml/2014/5/4/10 With the patch the value of event_f_flags is checked. When specifying an invalid value error EINVAL is returned. Internal flags are disallowed. File creation flags are disallowed: O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_TRUNC, and O_TTY_INIT. Flags which do not make sense with fanotify are disallowed: __O_TMPFILE, O_PATH, FASYNC, and O_DIRECT. This leaves us with the following allowed values: O_RDONLY, O_WRONLY, O_RDWR are basic functionality. The are stored in the bits given by O_ACCMODE. O_APPEND is working as expected. The value might be useful in a logging application which appends the current status each time the log is opened. O_LARGEFILE is needed for files exceeding 4GB on 32bit systems. O_NONBLOCK may be useful when monitoring slow devices like tapes. O_NDELAY is equal to O_NONBLOCK except for platform parisc. To avoid code breaking on parisc either both flags should be allowed or none. The patch allows both. __O_SYNC and O_DSYNC may be used to avoid data loss on power disruption. O_NOATIME may be useful to reduce disk activity. O_CLOEXEC may be useful, if separate processes shall be used to scan files. Once this patch is accepted, the fanotify_init.2 manpage has to be updated. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/notify/fanotify/fanotify_user.c: fix FAN_MARK_FLUSH flag checkingHeinrich Schuchardt
If fanotify_mark is called with illegal value of arguments flags and marks it usually returns EINVAL. When fanotify_mark is called with FAN_MARK_FLUSH the argument flags is not checked for irrelevant flags like FAN_MARK_IGNORED_MASK. The patch removes this inconsistency. If an irrelevant flag is set error EINVAL is returned. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fanotify: FAN_MARK_FLUSH: avoid having to provide a fake/invalid fd and pathHeinrich Schuchardt
Originally from Tvrtko Ursulin (https://lkml.org/lkml/2011/1/12/112) Avoid having to provide a fake/invalid fd and path when flushing marks Currently for a group to flush marks it has set it needs to provide a fake or invalid (but resolvable) file descriptor and path when calling fanotify_mark. This patch pulls the flush handling a bit up so file descriptor and path are completely ignored when flushing. I reworked the patch to be applicable again (the signature of fanotify_mark has changed since Tvrtko's work). Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06fanotify: fix -EOVERFLOW with large files on 64-bitWill Woods
On 64-bit systems, O_LARGEFILE is automatically added to flags inside the open() syscall (also openat(), blkdev_open(), etc). Userspace therefore defines O_LARGEFILE to be 0 - you can use it, but it's a no-op. Everything should be O_LARGEFILE by default. But: when fanotify does create_fd() it uses dentry_open(), which skips all that. And userspace can't set O_LARGEFILE in fanotify_init() because it's defined to 0. So if fanotify gets an event regarding a large file, the read() will just fail with -EOVERFLOW. This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit systems, using the same test as open()/openat()/etc. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821 Signed-off-by: Will Woods <wwoods@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03fanotify: move unrelated handling from copy_event_to_user()Jan Kara
Move code moving event structure to access_list from copy_event_to_user() to fanotify_read() where it is more logical (so that we can immediately see in the main loop that we either move the event to a different list or free it). Also move special error handling for permission events from copy_event_to_user() to the main loop to have it in one place with error handling for normal events. This makes copy_event_to_user() really only copy the event to user without any side effects. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: reorganize loop in fanotify_read()Jan Kara
Swap the error / "read ok" branches in the main loop of fanotify_read(). We will grow the "read ok" part in the next patch and this makes the indentation easier. Also it is more common to have error conditions inside an 'if' instead of the fast path. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: convert access_mutex to spinlockJan Kara
access_mutex is used only to guard operations on access_list. There's no need for sleeping within this lock so just make a spinlock out of it. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: use fanotify event structure for permission response processingJan Kara
Currently, fanotify creates new structure to track the fact that permission event has been reported to userspace and someone is waiting for a response to it. As event structures are now completely in the hands of each notification framework, we can use the event structure for this tracking instead of allocating a new structure. Since this makes the event structures for normal events and permission events even more different and the structures have different lifetime rules, we split them into two separate structures (where permission event structure contains the structure for a normal event). This makes normal events 8 bytes smaller and the code a tad bit cleaner. [akpm@linux-foundation.org: fix build] Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03fanotify: remove useless bypass_perm checkJan Kara
The prepare_for_access_response() function checks whether group->fanotify_data.bypass_perm is set. However this test can never be true because prepare_for_access_response() is called only from fanotify_read() which means fanotify group is alive with an active fd while bypass_perm is set from fanotify_release() when all file descriptors pointing to the group are closed and the group is going away. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-02-25fsnotify: Allocate overflow events with proper typeJan Kara
Commit 7053aee26a35 "fsnotify: do not share events between notification groups" used overflow event statically allocated in a group with the size of the generic notification event. This causes problems because some code looks at type specific parts of event structure and gets confused by a random data it sees there and causes crashes. Fix the problem by allocating overflow event with type corresponding to the group type so code cannot get confused. Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-25fanotify: Handle overflow in case of permission eventsJan Kara
If the event queue overflows when we are handling permission event, we will never get response from userspace. So we must avoid waiting for it. Change fsnotify_add_notify_event() to return whether overflow has happened so that we can detect it in fanotify_handle_event() and act accordingly. Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-18inotify: Fix reporting of cookies for inotify eventsJan Kara
My rework of handling of notification events (namely commit 7053aee26a35 "fsnotify: do not share events between notification groups") broke sending of cookies with inotify events. We didn't propagate the value passed to fsnotify() properly and passed 4 uninitialized bytes to userspace instead (so it is also an information leak). Sadly I didn't notice this during my testing because inotify cookies aren't used very much and LTP inotify tests ignore them. Fix the problem by passing the cookie value properly. Fixes: 7053aee26a3548ebaba046ae2e52396ccf56ac6c Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fanotify: Fix use after free for permission eventsJan Kara
Currently struct fanotify_event_info has been destroyed immediately after reporting its contents to userspace. However that is wrong for permission events because those need to stay around until userspace provides response which is filled back in fanotify_event_info. So change to code to free permission events only after we have got the response from userspace. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fsnotify: Do not return merged event from fsnotify_add_notify_event()Jan Kara
The event returned from fsnotify_add_notify_event() cannot ever be used safely as the event may be freed by the time the function returns (after dropping notification_mutex). So change the prototype to just return whether the event was added or merged into some existing event. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fanotify: Fix use after free in mask checkingJan Kara
We cannot use the event structure returned from fsnotify_add_notify_event() because that event can be freed by the time that function returns. Use the mask argument passed into the event handler directly instead. This also fixes a possible problem when we could unnecessarily wait for permission response for a normal fanotify event which got merged with a permission event. We also disallow merging of permission event with any other event so that we know the permission event which we just created is the one on which we should wait for permission response. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-28compat: fix sys_fanotify_markHeiko Carstens
Commit 91c2e0bcae72 ("unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE") added a new unified compat fanotify_mark syscall to be used by all architectures. Unfortunately the unified version merges the split mask parameter in a wrong way: the lower and higher word got swapped. This was discovered with glibc's tst-fanotify test case. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-22fsnotify: remove pointless NULL initializersJan Kara
We usually rely on the fact that struct members not specified in the initializer are set to NULL. So do that with fsnotify function pointers as well. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
2014-01-22fsnotify: remove .should_send_event callbackJan Kara
After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
2014-01-22fsnotify: do not share events between notification groupsJan Kara
Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09fanotify: put duplicate code for adding vfsmount/inode marks into an own ↵Lino Sanfilippo
function The code under the groups mark_mutex in fanotify_add_inode_mark() and fanotify_add_vfsmount_mark() is almost identical. So put it into a seperate function. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>
2013-07-09fanotify: fix races when adding/removing marksLino Sanfilippo
For both adding an event to an existing mark and destroying a mark we first have to find it via fsnotify_find_[inode|vfsmount]_mark(). But getting the mark and adding an event (or destroying it) is not done atomically. This opens a race where a thread is about to destroy a mark while another thread still finds the same mark and adds an event to its mask although it will be destroyed. Another race exists concerning the excess of a groups number of marks limit: When a mark is added the number of group marks is checked against the max number of marks per group and increased afterwards. Since check and increment is also not done atomically, this may result in 2 or more processes passing the check at the same time and increasing the number of group marks above the allowed limit. With this patch both races are avoided by doing the concerning operations with the groups mark mutex locked. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>
2013-07-09fanotify: info leak in copy_event_to_user()Dan Carpenter
The ->reserved field isn't cleared so we leak one byte of stack information to userspace. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Eric Paris <eparis@redhat.com> 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>
2013-06-29fanotify: quit wanking with FASYNC in ->release()Al Viro
... especially since there's no way to get that sucker on the list fsnotify_fasync() works with - the only thing adding to it is fsnotify_fasync() itself and it's never called for fanotify files while they are opened. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-09unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-04teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long longAl Viro
... and convert a bunch of SYSCALL_DEFINE ones to SYSCALL_DEFINE<n>, killing the boilerplate crap around them. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-23new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-21Merge branch 'for-next' of git://git.infradead.org/users/eparis/notifyLinus Torvalds
Pull filesystem notification updates from Eric Paris: "This pull mostly is about locking changes in the fsnotify system. By switching the group lock from a spin_lock() to a mutex() we can now hold the lock across things like iput(). This fixes a problem involving unmounting a fs and having inodes be busy, first pointed out by FAT, but reproducible with tmpfs. This also restores signal driven I/O for inotify, which has been broken since about 2.6.32." Ugh. I *hate* the timing of this. It was rebased after the merge window opened, and then left to sit with the pull request coming the day before the merge window closes. That's just crap. But apparently the patches themselves have been around for over a year, just gathering dust, so now it's suddenly critical. Fixed up semantic conflict in fs/notify/fdinfo.c as per Stephen Rothwell's fixes from -next. * 'for-next' of git://git.infradead.org/users/eparis/notify: inotify: automatically restart syscalls inotify: dont skip removal of watch descriptor if creation of ignored event failed fanotify: dont merge permission events fsnotify: make fasync generic for both inotify and fanotify fsnotify: change locking order fsnotify: dont put marks on temporary list when clearing marks by group fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark() fsnotify: pass group to fsnotify_destroy_mark() fsnotify: use a mutex instead of a spinlock to protect a groups mark list fanotify: add an extra flag to mark_remove_from_mask that indicates wheather a mark should be destroyed fsnotify: take groups mark_lock before mark lock fsnotify: use reference counting for groups fsnotify: introduce fsnotify_get_group() inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()
2012-12-18fs, notify: add procfs fdinfo helperCyrill Gorcunov
This allow us to print out fsnotify details such as watchee inode, device, mask and optionally a file handle. For inotify objects if kernel compiled with exportfs support the output will be | pos: 0 | flags: 02000000 | inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:11a1000020542153 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:49b1060023552153 If kernel compiled without exportfs support, the file handle won't be provided but inode and device only. | pos: 0 | flags: 02000000 | inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0 For fanotify the output is like | pos: 0 | flags: 04002 | fanotify flags:10 event-flags:0 | fanotify mnt_id:12 mask:3b ignored_mask:0 | fanotify ino:50205 sdev:800013 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:05020500fb1d47e7 To minimize impact on general fsnotify code the new functionality is gathered in fs/notify/fdinfo.c file. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: James Bottomley <jbottomley@parallels.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Helsley <matt.helsley@gmail.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...
2012-12-11fanotify: dont merge permission eventsLino Sanfilippo
Boyd Yang reported a problem for the case that multiple threads of the same thread group are waiting for a reponse for a permission event. In this case it is possible that some of the threads are never woken up, even if the response for the event has been received (see http://marc.info/?l=linux-kernel&m=131822913806350&w=2). The reason is that we are currently merging permission events if they belong to the same thread group. But we are not prepared to wake up more than one waiter for each event. We do wait_event(group->fanotify_data.access_waitq, event->response || atomic_read(&group->fanotify_data.bypass_perm)); and after that event->response = 0; which is the reason that even if we woke up all waiters for the same event some of them may see event->response being already set 0 again, then go back to sleep and block forever. With this patch we avoid that more than one thread is waiting for a response by not merging permission events for the same thread group any more. Reported-by: Boyd Yang <boyd.yang@gmail.com> Signed-off-by: Lino Sanfilippo <LinoSanfilipp@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-12-11fsnotify: make fasync generic for both inotify and fanotifyEric Paris
inotify is supposed to support async signal notification when information is available on the inotify fd. This patch moves that support to generic fsnotify functions so it can be used by all notification mechanisms. Signed-off-by: Eric Paris <eparis@redhat.com>
2012-12-11fsnotify: pass group to fsnotify_destroy_mark()Lino Sanfilippo
In fsnotify_destroy_mark() dont get the group from the passed mark anymore, but pass the group itself as an additional parameter to the function. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-12-11fanotify: add an extra flag to mark_remove_from_mask that indicates wheather ↵Lino Sanfilippo
a mark should be destroyed This patch adds an extra flag to mark_remove_from_mask() to inform the caller if the mark should be destroyed. With this we dont destroy the mark implicitly in the function itself any more but let the caller handle it. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-12-11inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()Lino Sanfilippo
Currently in fsnotify_put_group() the ref count of a group is decremented and if it becomes 0 fsnotify_destroy_group() is called. Since a groups ref count is only at group creation set to 1 and never increased after that a call to fsnotify_put_group() always results in a call to fsnotify_destroy_group(). With this patch fsnotify_destroy_group() is called directly. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-11-19treewide: fix typo of "suport" in various comments and KconfigMasanari Iida
Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-18fanotify: fix FAN_Q_OVERFLOW case of fanotify_read()Al Viro
If the FAN_Q_OVERFLOW bit set in event->mask, the fanotify event metadata will not contain a valid file descriptor, but copy_event_to_user() didn't check for that, and unconditionally does a fd_install() on the file descriptor. Which in turn will cause a BUG_ON() in __fd_install(). Introduced by commit 352e3b249284 ("fanotify: sanitize failure exits in copy_event_to_user()") Mea culpa - missed that path ;-/ Reported-by: Alex Shi <lkml.alex@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-09fanotify: fix missing breakEric Paris
Anders Blomdell noted in 2010 that Fanotify lost events and provided a test case. Eric Paris confirmed it was a bug and posted a fix to the list https://groups.google.com/forum/?fromgroups=#!topic/linux.kernel/RrJfTfyW2BE but never applied it. Repeated attempts over time to actually get him to apply it have never had a reply from anyone who has raised it So apply it anyway Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Anders Blomdell <anders.blomdell@control.lth.se> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-27switch simple cases of fget_light to fdgetAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27fanotify: sanitize failure exits in copy_event_to_user()Al Viro
* do copy_to_user() before prepare_for_access_response(); that kills the need in remove_access_response(). * don't do fd_install() until we are past the last possible failure exit. Don't use sys_close() on cleanup side - just put_unused_fd() and fput(). Less racy that way... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22switch dentry_open() to struct path, make it grab references itselfAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>