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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
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>
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>
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>
This update contains:
o RENAME_WHITEOUT support
o conversion of per-cpu superblock accounting to use generic counters
o 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
o 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.
o FALLOC_FL_INSERT_RANGE support for inserting holes into a file via direct
extent manipulation to avoid needing to copy data within the file
o attribute block header field overflow fix for 64k block size filesystems
o 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.
o lots of cleanups and bug fixes
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Merge tag 'xfs-for-linus-4.1-rc1' of 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()
...
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.) 6de0ec00ba ("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.) 27ac0ffeac ("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: 27ac0ffeac ("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>
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>
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>
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
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>
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>
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
...
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>
... 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>
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>
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>
Fix the broken check for calling sys_fallocate() on an active swapfile,
introduced by commit 0790b31b69 ("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>
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>
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>
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.
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Merge tag 'ext4_for_linus_stable' of 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
...
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
...
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>
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>
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>
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
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Merge tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
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>
[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>
Jann Horn