Push clamping timestamps into notify_change(), so in-kernel
callers like nfsd and overlayfs will get similar timestamp
set behavior as utimes.
AV: get rid of clamping in ->setattr() instances; we don't need
to bother with that there, with notify_change() doing normalization
in all cases now (it already did for implicit case, since current_time()
clamps).
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 42e729b9dd ("utimes: Clamp the timestamps before update")
Cc: stable@vger.kernel.org # v5.4
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull inode timestamps conversion to timespec64 from Arnd Bergmann:
"This is a late set of changes from Deepa Dinamani doing an automated
treewide conversion of the inode and iattr structures from 'timespec'
to 'timespec64', to push the conversion from the VFS layer into the
individual file systems.
As Deepa writes:
'The series aims to switch vfs timestamps to use struct timespec64.
Currently vfs uses struct timespec, which is not y2038 safe.
The series involves the following:
1. Add vfs helper functions for supporting struct timepec64
timestamps.
2. Cast prints of vfs timestamps to avoid warnings after the switch.
3. Simplify code using vfs timestamps so that the actual replacement
becomes easy.
4. Convert vfs timestamps to use struct timespec64 using a script.
This is a flag day patch.
Next steps:
1. Convert APIs that can handle timespec64, instead of converting
timestamps at the boundaries.
2. Update internal data structures to avoid timestamp conversions'
Thomas Gleixner adds:
'I think there is no point to drag that out for the next merge
window. The whole thing needs to be done in one go for the core
changes which means that you're going to play that catchup game
forever. Let's get over with it towards the end of the merge window'"
* tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground:
pstore: Remove bogus format string definition
vfs: change inode times to use struct timespec64
pstore: Convert internal records to timespec64
udf: Simplify calls to udf_disk_stamp_to_time
fs: nfs: get rid of memcpys for inode times
ceph: make inode time prints to be long long
lustre: Use long long type to print inode time
fs: add timespec64_truncate()
Allow users with CAP_SYS_CHOWN over the superblock of a filesystem to
chown files when inode owner is invalid. Ordinarily the
capable_wrt_inode_uidgid check is sufficient to allow access to files
but when the underlying filesystem has uids or gids that don't map to
the current user namespace it is not enough, so the chown permission
checks need to be extended to allow this case.
Calling chown on filesystem nodes whose uid or gid don't map is
necessary if those nodes are going to be modified as writing back
inodes which contain uids or gids that don't map is likely to cause
filesystem corruption of the uid or gid fields.
Once chown has been called the existing capable_wrt_inode_uidgid
checks are sufficient to allow the owner of a superblock to do anything
the global root user can do with an appropriate set of capabilities.
An ordinary filesystem mountable by a userns root will limit all uids
and gids in s_user_ns or the INVALID_UID and INVALID_GID to flag all
others. So having this added permission limited to just INVALID_UID
and INVALID_GID is sufficient to handle every case on an ordinary filesystem.
Of the virtual filesystems at least proc is known to set s_user_ns to
something other than &init_user_ns, while at the same time presenting
some files owned by GLOBAL_ROOT_UID. Those files the mounter of proc
in a user namespace should not be able to chown to get access to.
Limiting the relaxation in permission to just the minimum of allowing
changing INVALID_UID and INVALID_GID prevents problems with cases like
that.
The original version of this patch was written by: Seth Forshee. I
have rewritten and rethought this patch enough so it's really not the
same thing (certainly it needs a different description), but he
deserves credit for getting out there and getting the conversation
started, and finding the potential gotcha's and putting up with my
semi-paranoid feedback.
Inspired-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.
Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently, notify_change() clears capabilities or IMA attributes by
calling security_inode_killpriv() before calling into ->setattr. Thus it
happens before any other permission checks in inode_change_ok() and user
is thus allowed to trigger clearing of capabilities or IMA attributes
for any file he can look up e.g. by calling chown for that file. This is
unexpected and can lead to user DoSing a system.
Fix the problem by calling security_inode_killpriv() at the end of
inode_change_ok() instead of from notify_change(). At that moment we are
sure user has permissions to do the requested change.
References: CVE-2015-1350
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
This fixes a bug where the permission was not properly checked in
overlayfs. The testcase is ltp/utimensat01.
It is also cleaner and safer to do the permission checking in the vfs
helper instead of the caller.
This patch introduces an additional ia_valid flag ATTR_TOUCH (since
touch(1) is the most obvious user of utimes(NULL)) that is passed into
notify_change whenever the conditions for this special permission checking
mode are met.
Reported-by: Aihua Zhang <zhangaihua1@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Aihua Zhang <zhangaihua1@huawei.com>
Cc: <stable@vger.kernel.org> # v3.18+
When a filesystem outside of init_user_ns is mounted it could have
uids and gids stored in it that do not map to init_user_ns.
The plan is to allow those filesystems to set i_uid to INVALID_UID and
i_gid to INVALID_GID for unmapped uids and gids and then to handle
that strange case in the vfs to ensure there is consistent robust
handling of the weirdness.
Upon a careful review of the vfs and filesystems about the only case
where there is any possibility of confusion or trouble is when the
inode is written back to disk. In that case filesystems typically
read the inode->i_uid and inode->i_gid and write them to disk even
when just an inode timestamp is being updated.
Which leads to a rule that is very simple to implement and understand
inodes whose i_uid or i_gid is not valid may not be written.
In dealing with access times this means treat those inodes as if the
inode flag S_NOATIME was set. Reads of the inodes appear safe and
useful, but any write or modification is disallowed. The only inode
write that is allowed is a chown that sets the uid and gid on the
inode to valid values. After such a chown the inode is normal and may
be treated as such.
Denying all writes to inodes with uids or gids unknown to the vfs also
prevents several oddball cases where corruption would have occurred
because the vfs does not have complete information.
One problem case that is prevented is attempting to use the gid of a
directory for new inodes where the directories sgid bit is set but the
directories gid is not mapped.
Another problem case avoided is attempting to update the evm hash
after setxattr, removexattr, and setattr. As the evm hash includeds
the inode->i_uid or inode->i_gid not knowning the uid or gid prevents
a correct evm hash from being computed. evm hash verification also
fails when i_uid or i_gid is unknown but that is essentially harmless
as it does not cause filesystem corruption.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add checks to notify_change to verify that uid and gid changes
will map into the superblock's user namespace. If they do not
fail with -EOVERFLOW.
This is mandatory so that fileystems don't have to even think
of dealing with ia_uid and ia_gid that
--EWB Moved the test from inode_change_ok to notify_change
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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>
The kernel has no concept of capabilities with respect to inodes; inodes
exist independently of namespaces. For example, inode_capable(inode,
CAP_LINUX_IMMUTABLE) would be nonsense.
This patch changes inode_capable to check for uid and gid mappings and
renames it to capable_wrt_inode_uidgid, which should make it more
obvious what it does.
Fixes CVE-2014-4014.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently notify_change directly updates i_version for size updates,
which not only is counter to how all other fields are updated through
struct iattr, but also breaks XFS, which need inode updates to happen
under its own lock, and synchronized to the structure that gets written
to the log.
Remove the update in the common code, and it to btrfs and ext4,
XFS already does a proper updaste internally and currently gets a
double update with the existing code.
IMHO this is 3.13 and -stable material and should go in through the XFS
tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
- Allow chown if CAP_CHOWN is present in the current user namespace
and the uid of the inode maps into the current user namespace, and
the destination uid or gid maps into the current user namespace.
- Allow perserving setgid when changing an inode if CAP_FSETID is
present in the current user namespace and the owner of the file has
a mapping into the current user namespace.
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Changing an inode's metadata may result in our not needing to appraise
the file. In such cases, we must remove 'security.ima'.
Changelog v1:
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
When a file is truncated with truncate()/ftruncate() and then closed,
iversion is not updated. This patch uses ATTR_SIZE flag as an indication
to increment iversion.
Mimi said:
On fput(), i_version is used to detect and flag files that have changed
and need to be re-measured in the IMA measurement policy. When a file
is truncated with truncate()/ftruncate() and then closed, i_version is
not updated. As a result, although the file has changed, it will not be
re-measured and added to the IMA measurement list on subsequent access.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
