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* fs: stream_open - opener for stream-like files so that read and write can ↵Kirill Smelkov2019-06-111-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | run simultaneously without deadlock commit 10dce8af34226d90fa56746a934f8da5dcdba3df upstream. Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> [ backport to 4.4: actually fixed deadlock on /proc/xen/xenbus as 581d21a2d02a was not backported to 4.4 ] Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: completely ignore unknown open flagsChristoph Hellwig2017-07-151-0/+6
| | | | | | | | | | | | | commit 629e014bb8349fcf7c1e4df19a842652ece1c945 upstream. Currently we just stash anything we got into file->f_flags, and the report it in fcntl(F_GETFD). This patch just clears out all unknown flags so that we don't pass them to the fs or report them. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfs: add vfs_select_inode() helperMiklos Szeredi2016-05-181-8/+4
| | | | | | | | commit 54d5ca871e72f2bb172ec9323497f01cd5091ec7 upstream. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn2016-04-121-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 378c6520e7d29280f400ef2ceaf155c86f05a71a upstream. This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfs: Commit to never having exectuables on proc and sysfs.Eric W. Biederman2015-07-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today proc and sysfs do not contain any executable files. Several applications today mount proc or sysfs without noexec and nosuid and then depend on there being no exectuables files on proc or sysfs. Having any executable files show on proc or sysfs would cause a user space visible regression, and most likely security problems. Therefore commit to never allowing executables on proc and sysfs by adding a new flag to mark them as filesystems without executables and enforce that flag. Test the flag where MNT_NOEXEC is tested today, so that the only user visible effect will be that exectuables will be treated as if the execute bit is cleared. The filesystems proc and sysfs do not currently incoporate any executable files so this does not result in any user visible effects. This makes it unnecessary to vet changes to proc and sysfs tightly for adding exectuable files or changes to chattr that would modify existing files, as no matter what the individual file say they will not be treated as exectuable files by the vfs. Not having to vet changes to closely is important as without this we are only one proc_create call (or another goof up in the implementation of notify_change) from having problematic executables on proc. Those mistakes are all too easy to make and would create a situation where there are security issues or the assumptions of some program having to be broken (and cause userspace regressions). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* fs: Call security_ops->inode_killpriv on truncateJan Kara2015-06-231-2/+4
| | | | | | | | | | | | | | | | | | | Comment in include/linux/security.h says that ->inode_killpriv() should be called when setuid bit is being removed and that similar security labels (in fact this applies only to file capabilities) should be removed at this time as well. However we don't call ->inode_killpriv() when we remove suid bit on truncate. We fix the problem by calling ->inode_need_killpriv() and subsequently ->inode_killpriv() on truncate the same way as we do it on file write. After this patch there's only one user of should_remove_suid() - ocfs2 - and indeed it's buggy because it doesn't call ->inode_killpriv() on write. However fixing it is difficult because of special locking constraints. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: add file_path() helperMiklos Szeredi2015-06-231-0/+6
| | | | | | | | | | Turn d_path(&file->f_path, ...); into file_path(file, ...); Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* overlayfs: Make f_path always point to the overlay and f_inode to the underlayDavid Howells2015-06-191-23/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:38 5 -> /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:22 5 -> /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: Handle lower layer dentry/inode in pathwalkDavid Howells2015-05-111-1/+1
| | | | | | | Make use of d_backing_inode() in pathwalk to gain access to an inode or dentry that's on a lower layer. Signed-off-by: David Howells <dhowells@redhat.com>
* Merge tag 'xfs-for-linus-4.1-rc1' of ↵Linus Torvalds2015-04-241-2/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs update from Dave Chinner: "This update contains: - RENAME_WHITEOUT support - conversion of per-cpu superblock accounting to use generic counters - new inode mmap lock so that we can lock page faults out of truncate, hole punch and other direct extent manipulation functions to avoid racing mmap writes from causing data corruption - rework of direct IO submission and completion to solve data corruption issue when running concurrent extending DIO writes. Also solves problem of running IO completion transactions in interrupt context during size extending AIO writes. - FALLOC_FL_INSERT_RANGE support for inserting holes into a file via direct extent manipulation to avoid needing to copy data within the file - attribute block header field overflow fix for 64k block size filesystems - Lots of changes to log messaging to be more informative and concise when errors occur. Also prevent a lot of unnecessary log spamming due to cascading failures in error conditions. - lots of cleanups and bug fixes One thing of note is the direct IO fixes that we merged last week after the window opened. Even though a little late, they fix a user reported data corruption and have been pretty well tested. I figured there was not much point waiting another 2 weeks for -rc1 to be released just so I could send them to you..." * tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits) xfs: using generic_file_direct_write() is unnecessary xfs: direct IO EOF zeroing needs to drain AIO xfs: DIO write completion size updates race xfs: DIO writes within EOF don't need an ioend xfs: handle DIO overwrite EOF update completion correctly xfs: DIO needs an ioend for writes xfs: move DIO mapping size calculation xfs: factor DIO write mapping from get_blocks xfs: unlock i_mutex in xfs_break_layouts xfs: kill unnecessary firstused overflow check on attr3 leaf removal xfs: use larger in-core attr firstused field and detect overflow xfs: pass attr geometry to attr leaf header conversion functions xfs: disallow ro->rw remount on norecovery mount xfs: xfs_shift_file_space can be static xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate fs: Add support FALLOC_FL_INSERT_RANGE for fallocate xfs: Fix incorrect positive ENOMEM return xfs: xfs_mru_cache_insert() should use GFP_NOFS xfs: %pF is only for function pointers xfs: fix shadow warning in xfs_da3_root_split() ...
| * fs: Add support FALLOC_FL_INSERT_RANGE for fallocateNamjae Jeon2015-03-251-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | FALLOC_FL_INSERT_RANGE command is the opposite command of FALLOC_FL_COLLAPSE_RANGE that is needed for someone who wants to add some data in the middle of file. FALLOC_FL_INSERT_RANGE will create space for writing new data within a file after shifting extents to right as given length. This command also has same limitations as FALLOC_FL_COLLAPSE_RANGE in that operations need to be filesystem block boundary aligned and cannot cross the current EOF. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* | ->aio_read and ->aio_write removedAl Viro2015-04-111-2/+2
| | | | | | | | | | | | no remaining users Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | NFS: fix BUG() crash in notify_change() with patch to chown_common()Andrew Elble2015-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have observed a BUG() crash in fs/attr.c:notify_change(). The crash occurs during an rsync into a filesystem that is exported via NFS. 1.) fs/attr.c:notify_change() modifies the caller's version of attr. 2.) 6de0ec00ba8d ("VFS: make notify_change pass ATTR_KILL_S*ID to setattr operations") introduced a BUG() restriction such that "no function will ever call notify_change() with both ATTR_MODE and ATTR_KILL_S*ID set". Under some circumstances though, it will have assisted in setting the caller's version of attr to this very combination. 3.) 27ac0ffeac80 ("locks: break delegations on any attribute modification") introduced code to handle breaking delegations. This can result in notify_change() being re-called. attr _must_ be explicitly reset to avoid triggering the BUG() established in #2. 4.) The path that that triggers this is via fs/open.c:chmod_common(). The combination of attr flags set here and in the first call to notify_change() along with a later failed break_deleg_wait() results in notify_change() being called again via retry_deleg without resetting attr. Solution is to move retry_deleg in chmod_common() a bit further up to ensure attr is completely reset. There are other places where this seemingly could occur, such as fs/utimes.c:utimes_common(), but the attr flags are not initially set in such a way to trigger this. Fixes: 27ac0ffeac80 ("locks: break delegations on any attribute modification") Reported-by: Eric Meddaugh <etmsys@rit.edu> Tested-by: Eric Meddaugh <etmsys@rit.edu> Signed-off-by: Andrew Elble <aweits@rit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | drop bogus check in file_open_root()Al Viro2015-04-111-3/+0
|/ | | | | | | | For one thing, LOOKUP_DIRECTORY will be dealt with in do_last(). For another, name can be an empty string, but not NULL - no callers pass that and it would oops immediately if they would. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'getname2' of ↵Linus Torvalds2015-02-171-2/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull getname/putname updates from Al Viro: "Rework of getname/getname_kernel/etc., mostly from Paul Moore. Gets rid of quite a pile of kludges between namei and audit..." * 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: audit: replace getname()/putname() hacks with reference counters audit: fix filename matching in __audit_inode() and __audit_inode_child() audit: enable filename recording via getname_kernel() simpler calling conventions for filename_mountpoint() fs: create proper filename objects using getname_kernel() fs: rework getname_kernel to handle up to PATH_MAX sized filenames cut down the number of do_path_lookup() callers
| * fs: create proper filename objects using getname_kernel()Paul Moore2015-01-231-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several areas in the kernel that create temporary filename objects using the following pattern: int func(const char *name) { struct filename *file = { .name = name }; ... return 0; } ... which for the most part works okay, but it causes havoc within the audit subsystem as the filename object does not persist beyond the lifetime of the function. This patch converts all of these temporary filename objects into proper filename objects using getname_kernel() and putname() which ensure that the filename object persists until the audit subsystem is finished with it. Also, a special thanks to Al Viro, Guenter Roeck, and Sabrina Dubroca for helping resolve a difficult kernel panic on boot related to a use-after-free problem in kern_path_create(); the thread can be seen at the link below: * https://lkml.org/lkml/2015/1/20/710 This patch includes code that was either based on, or directly written by Al in the above thread. CC: viro@zeniv.linux.org.uk CC: linux@roeck-us.net CC: sd@queasysnail.net CC: linux-fsdevel@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | vfs: remove get_xip_memMatthew Wilcox2015-02-161-4/+1
|/ | | | | | | | | | | | | | | | | | | | | | All callers of get_xip_mem() are now gone. Remove checks for it, initialisers of it, documentation of it and the only implementation of it. Also remove mm/filemap_xip.c as it is now empty. Also remove documentation of the long-gone get_xip_page(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2014-12-161-2/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull nfsd updates from Bruce Fields: "A comparatively quieter cycle for nfsd this time, but still with two larger changes: - RPC server scalability improvements from Jeff Layton (using RCU instead of a spinlock to find idle threads). - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna Schumaker, enabling fallocate on new clients" * 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits) nfsd4: fix xdr4 count of server in fs_location4 nfsd4: fix xdr4 inclusion of escaped char sunrpc/cache: convert to use string_escape_str() sunrpc: only call test_bit once in svc_xprt_received fs: nfsd: Fix signedness bug in compare_blob sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt sunrpc: convert to lockless lookup of queued server threads sunrpc: fix potential races in pool_stats collection sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it sunrpc: require svc_create callers to pass in meaningful shutdown routine sunrpc: have svc_wake_up only deal with pool 0 sunrpc: convert sp_task_pending flag to use atomic bitops sunrpc: move rq_cachetype field to better optimize space sunrpc: move rq_splice_ok flag into rq_flags sunrpc: move rq_dropme flag into rq_flags sunrpc: move rq_usedeferral flag to rq_flags sunrpc: move rq_local field to rq_flags sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it nfsd: minor off by one checks in __write_versions() sunrpc: release svc_pool_map reference when serv allocation fails ...
| * merge nfs bugfixes into nfsd for-3.19 branchJ. Bruce Fields2014-11-191-2/+21
| |\ | | | | | | | | | | | | In addition to nfsd bugfixes, there are some fixes in -rc5 for client bugs that can interfere with my testing.
| * | VFS: Rename do_fallocate() to vfs_fallocate()Anna Schumaker2014-11-071-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function needs to be exported so it can be used by the NFSD module when responding to the new ALLOCATE and DEALLOCATE operations in NFS v4.2. Christoph Hellwig suggested renaming the function to stay consistent with how other vfs functions are named. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | | fallocate: create FAN_MODIFY and IN_MODIFY eventsHeinrich Schuchardt2014-12-131-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fanotify and the inotify API can be used to monitor changes of the file system. System call fallocate() modifies files. Hence it should trigger the corresponding fanotify (FAN_MODIFY) and inotify (IN_MODIFY) events. The most interesting case is FALLOC_FL_COLLAPSE_RANGE because this value allows to create arbitrary file content from random data. This patch adds the missing call to fsnotify_modify(). The FAN_MODIFY and IN_MODIFY event will be created when fallocate() succeeds. It will even be created if the file length remains unchanged, e.g. when calling fanotify with flag FALLOC_FL_KEEP_SIZE. This logic was primarily chosen to keep the coding simple. It resembles the logic of the write() system call. When we call write() we always create a FAN_MODIFY event, even in the case of overwriting with identical data. Events FAN_MODIFY and IN_MODIFY do not provide any guarantee that data was actually changed. Furthermore even if if the filesize remains unchanged, fallocate() may influence whether a subsequent write() will succeed and hence the fallocate() call may be considered a modification. The fallocate(2) man page teaches: After a successful call, subsequent writes into the range specified by offset and len are guaranteed not to fail because of lack of disk space. So calling fallocate(fd, FALLOC_FL_KEEP_SIZE, offset, len) may result in different outcomes of a subsequent write depending on the values of offset and len. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@parisplace.org> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | new helper: audit_file()Al Viro2014-11-191-2/+2
| |/ |/| | | | | | | | | | | | | | | ... for situations when we don't have any candidate in pathnames - basically, in descriptor-based syscalls. [Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | vfs: add i_op->dentry_open()Miklos Szeredi2014-10-241-2/+21
|/ | | | | | | Add a new inode operation i_op->dentry_open(). This is for stacked filesystems that want to return a struct file from a different filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* vfs: fix check for fallocate on active swapfileEric Biggers2014-08-011-3/+2
| | | | | | | | | Fix the broken check for calling sys_fallocate() on an active swapfile, introduced by commit 0790b31b69374ddadefe ("fs: disallow all fallocate operation on active swapfile"). Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new methods: ->read_iter() and ->write_iter()Al Viro2014-05-061-2/+4
| | | | | | | | | | | | | | | | | | Beginning to introduce those. Just the callers for now, and it's clumsier than it'll eventually become; once we finish converting aio_read and aio_write instances, the things will get nicer. For now, these guys are in parallel to ->aio_read() and ->aio_write(); they take iocb and iov_iter, with everything in iov_iter already validated. File offset is passed in iocb->ki_pos, iov/nr_segs - in iov_iter. Main concerns in that series are stack footprint and ability to split the damn thing cleanly. [fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* replace checking for ->read/->aio_read presence with check in ->f_modeAl Viro2014-05-061-0/+4
| | | | | | | | | | | Since we are about to introduce new methods (read_iter/write_iter), the tests in a bunch of places would have to grow inconveniently. Check once (at open() time) and store results in ->f_mode as FMODE_CAN_READ and FMODE_CAN_WRITE resp. It might end up being a temporary measure - once everything switches from ->aio_{read,write} to ->{read,write}_iter it might make sense to return to open-coded checks. We'll see... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds2014-04-201-12/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "These are regression and bug fixes for ext4. We had a number of new features in ext4 during this merge window (ZERO_RANGE and COLLAPSE_RANGE fallocate modes, renameat, etc.) so there were many more regression and bug fixes this time around. It didn't help that xfstests hadn't been fully updated to fully stress test COLLAPSE_RANGE until after -rc1" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (31 commits) ext4: disable COLLAPSE_RANGE for bigalloc ext4: fix COLLAPSE_RANGE failure with 1KB block size ext4: use EINVAL if not a regular file in ext4_collapse_range() ext4: enforce we are operating on a regular file in ext4_zero_range() ext4: fix extent merging in ext4_ext_shift_path_extents() ext4: discard preallocations after removing space ext4: no need to truncate pagecache twice in collapse range ext4: fix removing status extents in ext4_collapse_range() ext4: use filemap_write_and_wait_range() correctly in collapse range ext4: use truncate_pagecache() in collapse range ext4: remove temporary shim used to merge COLLAPSE_RANGE and ZERO_RANGE ext4: fix ext4_count_free_clusters() with EXT4FS_DEBUG and bigalloc enabled ext4: always check ext4_ext_find_extent result ext4: fix error handling in ext4_ext_shift_extents ext4: silence sparse check warning for function ext4_trim_extent ext4: COLLAPSE_RANGE only works on extent-based files ext4: fix byte order problems introduced by the COLLAPSE_RANGE patches ext4: use i_size_read in ext4_unaligned_aio() fs: disallow all fallocate operation on active swapfile fs: move falloc collapse range check into the filesystem methods ...
| * fs: disallow all fallocate operation on active swapfileLukas Czerner2014-04-121-0/+7
| | | | | | | | | | | | | | | | | | | | Currently some file system have IS_SWAPFILE check in their fallocate implementations and some do not. However we should really prevent any fallocate operation on swapfile so move the check to vfs and remove the redundant checks from the file systems fallocate implementations. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| * fs: move falloc collapse range check into the filesystem methodsLukas Czerner2014-04-121-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently in do_fallocate in collapse range case we're checking whether offset + len is not bigger than i_size. However there is nothing which would prevent i_size from changing so the check is pointless. It should be done in the file system itself and the file system needs to make sure that i_size is not going to change. The i_size check for the other fallocate modes are also done in the filesystems. As it is now we can easily crash the kernel by having two processes doing truncate and fallocate collapse range at the same time. This can be reproduced on ext4 and it is theoretically possible on xfs even though I was not able to trigger it with this simple test. This commit removes the check from do_fallocate and adds it to the file system. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Acked-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * fs: prevent doing FALLOC_FL_ZERO_RANGE on append only fileLukas Czerner2014-04-121-4/+2
| | | | | | | | | | | | | | | | | | Currently punch hole and collapse range fallocate operation are not allowed on append only file. This should be case for zero range as well. Fix it by allowing only pure fallocate (possibly with keep size set). Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-04-121-52/+16
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
| * tidy do_dentry_open() up a bitAl Viro2014-04-011-12/+10
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * mark struct file that had write access grabbed by open()Al Viro2014-04-011-5/+4
| | | | | | | | | | | | | | | | | | new flag in ->f_mode - FMODE_WRITER. Set by do_dentry_open() in case when it has grabbed write access, checked by __fput() to decide whether it wants to drop the sucker. Allows to stop bothering with mnt_clone_write() in alloc_file(), along with fewer special_file() checks. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fold __get_file_write_access() into its only callerAl Viro2014-04-011-19/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * get rid of DEBUG_WRITECOUNTAl Viro2014-04-011-8/+0
| | | | | | | | | | | | it only makes control flow in __fput() and friends more convoluted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * don't bother with {get,put}_write_access() on non-regular filesAl Viro2014-04-011-19/+7
| | | | | | | | | | | | | | | | | | it's pointless and actually leads to wrong behaviour in at least one moderately convoluted case (pipe(), close one end, try to get to another via /proc/*/fd and run into ETXTBUSY). Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfsLinus Torvalds2014-04-041-3/+26
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull xfs update from Dave Chinner: "There are a couple of new fallocate features in this request - it was decided that it was easiest to push them through the XFS tree using topic branches and have the ext4 support be based on those branches. Hence you may see some overlap with the ext4 tree merge depending on how they including those topic branches into their tree. Other than that, there is O_TMPFILE support, some cleanups and bug fixes. The main changes in the XFS tree for 3.15-rc1 are: - O_TMPFILE support - allowing AIO+DIO writes beyond EOF - FALLOC_FL_COLLAPSE_RANGE support for fallocate syscall and XFS implementation - FALLOC_FL_ZERO_RANGE support for fallocate syscall and XFS implementation - IO verifier cleanup and rework - stack usage reduction changes - vm_map_ram NOIO context fixes to remove lockdep warings - various bug fixes and cleanups" * tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs: (34 commits) xfs: fix directory hash ordering bug xfs: extra semi-colon breaks a condition xfs: Add support for FALLOC_FL_ZERO_RANGE fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate xfs: inode log reservations are still too small xfs: xfs_check_page_type buffer checks need help xfs: avoid AGI/AGF deadlock scenario for inode chunk allocation xfs: use NOIO contexts for vm_map_ram xfs: don't leak EFSBADCRC to userspace xfs: fix directory inode iolock lockdep false positive xfs: allocate xfs_da_args to reduce stack footprint xfs: always do log forces via the workqueue xfs: modify verifiers to differentiate CRC from other errors xfs: print useful caller information in xfs_error_report xfs: add xfs_verifier_error() xfs: add helper for updating checksums on xfs_bufs xfs: add helper for verifying checksums on xfs_bufs xfs: Use defines for CRC offsets in all cases xfs: skip pointless CRC updates after verifier failures xfs: Add support FALLOC_FL_COLLAPSE_RANGE for fallocate ...
| * fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocateLukas Czerner2014-03-131-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce new FALLOC_FL_ZERO_RANGE flag for fallocate. This has the same functionality as xfs ioctl XFS_IOC_ZERO_RANGE. It can be used to convert a range of file to zeros preferably without issuing data IO. Blocks should be preallocated for the regions that span holes in the file, and the entire range is preferable converted to unwritten extents - even though file system may choose to zero out the extent or do whatever which will result in reading zeros from the range while the range remains allocated for the file. This can be also used to preallocate blocks past EOF in the same way as with fallocate. Flag FALLOC_FL_KEEP_SIZE which should cause the inode size to remain the same. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * fs: Add new flag(FALLOC_FL_COLLAPSE_RANGE) for fallocateNamjae Jeon2014-02-241-3/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is in response of the following post: http://lwn.net/Articles/556136/ "ext4: introduce two new ioctls" Dave chinner suggested that truncate_block_range (which was one of the ioctls name) should be a fallocate operation and not any fs specific ioctl, hence we add this functionality to new flags of fallocate. This new functionality of collapsing range could be used by media editing tools which does non linear editing to quickly purge and edit parts of a media file. This will immensely improve the performance of these operations. The limitation of fs block size aligned offsets can be easily handled by media codecs which are encapsulated in a conatiner as they have to just change the offset to next keyframe value to match the proper alignment. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* | vfs: atomic f_pos accesses as per POSIXLinus Torvalds2014-03-101-0/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our write() system call has always been atomic in the sense that you get the expected thread-safe contiguous write, but we haven't actually guaranteed that concurrent writes are serialized wrt f_pos accesses, so threads (or processes) that share a file descriptor and use "write()" concurrently would quite likely overwrite each others data. This violates POSIX.1-2008/SUSv4 Section XSI 2.9.7 that says: "2.9.7 Thread Interactions with Regular File Operations All of the following functions shall be atomic with respect to each other in the effects specified in POSIX.1-2008 when they operate on regular files or symbolic links: [...]" and one of the effects is the file position update. This unprotected file position behavior is not new behavior, and nobody has ever cared. Until now. Yongzhi Pan reported unexpected behavior to Michael Kerrisk that was due to this. This resolves the issue with a f_pos-specific lock that is taken by read/write/lseek on file descriptors that may be shared across threads or processes. Reported-by: Yongzhi Pan <panyongzhi@gmail.com> Reported-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* locks: break delegations on any attribute modificationJ. Bruce Fields2013-11-091-4/+18
| | | | | | | | | | | | | NFSv4 uses leases to guarantee that clients can cache metadata as well as data. Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: David Howells <dhowells@redhat.com> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Dustin Kirkland <dustin.kirkland@gazzang.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of s_files and files_lockAl Viro2013-11-091-2/+0
| | | | | | | | The only thing we need it for is alt-sysrq-r (emergency remount r/o) and these days we can do just as well without going through the list of files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* file->f_op is never NULL...Al Viro2013-10-241-2/+6
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: improve i_op->atomic_open() documentationMiklos Szeredi2013-09-161-3/+18
| | | | | | | | | | | | | | | | Fix documentation of ->atomic_open() and related functions: finish_open() and finish_no_open(). Also add details that seem to be unclear and a source of bugs (some of which are fixed in the following series). Cc-ing maintainers of all filesystems implementing ->atomic_open(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Sage Weil <sage@inktank.com> Cc: Steve French <sfrench@samba.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-09-071-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace changes from Eric Biederman: "This is an assorted mishmash of small cleanups, enhancements and bug fixes. The major theme is user namespace mount restrictions. nsown_capable is killed as it encourages not thinking about details that need to be considered. A very hard to hit pid namespace exiting bug was finally tracked and fixed. A couple of cleanups to the basic namespace infrastructure. Finally there is an enhancement that makes per user namespace capabilities usable as capabilities, and an enhancement that allows the per userns root to nice other processes in the user namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Kill nsown_capable it makes the wrong thing easy capabilities: allow nice if we are privileged pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD userns: Allow PR_CAPBSET_DROP in a user namespace. namespaces: Simplify copy_namespaces so it is clear what is going on. pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup sysfs: Restrict mounting sysfs userns: Better restrictions on when proc and sysfs can be mounted vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces kernel/nsproxy.c: Improving a snippet of code. proc: Restrict mounting the proc filesystem vfs: Lock in place mounts from more privileged users
| * userns: Kill nsown_capable it makes the wrong thing easyEric W. Biederman2013-08-301-1/+1
| | | | | | | | | | | | | | | | | | | | nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and CAP_SETGID. For the existing users it doesn't noticably simplify things and from the suggested patches I have seen it encourages people to do the wrong thing. So remove nsown_capable. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | switch fchmod() to fdgetAl Viro2013-09-031-6/+5
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | fs: Fix file mode for O_TMPFILEAndy Lutomirski2013-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | O_TMPFILE, like O_CREAT, should respect the requested mode and should create regular files. This fixes two bugs: O_TMPFILE required privilege (because the mode ended up as 000) and it produced bogus inodes with no type. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | allow O_TMPFILE to work with O_WRONLYAl Viro2013-07-201-0/+2
|/ | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Safer ABI for O_TMPFILEAl Viro2013-07-131-2/+2
| | | | | | | | [suggested by Rasmus Villemoes] make O_DIRECTORY | O_RDWR part of O_TMPFILE; that will fail on old kernels in a lot more cases than what I came up with. And make sure O_CREAT doesn't get there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>