Pull overlayfs fixes from Miklos Szeredi:
"This contains a fix for a potential crash/corruption issue and another
where the suid/sgid bits weren't cleared on write"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: verify upper dentry in ovl_remove_and_whiteout()
ovl: Copy up underlying inode's ->i_mode to overlay inode
ovl: handle ATTR_KILL*
The upper dentry may become stale before we call ovl_lock_rename_workdir.
For example, someone could (mistakenly or maliciously) manually unlink(2)
it directly from upperdir.
To ensure it is not stale, let's lookup it after ovl_lock_rename_workdir
and and check if it matches the upper dentry.
Essentially, it is the same problem and similar solution as in
commit 11f3710417 ("ovl: verify upper dentry before unlink and rename").
Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
Without this check, the following XFS_I invocations would return bad
pointers when used on non-XFS inodes (perhaps pointers into preceding
allocator chunks).
This could be used by an attacker to trick xfs_swap_extents into
performing locking operations on attacker-chosen structures in kernel
memory, potentially leading to code execution in the kernel. (I have
not investigated how likely this is to be usable for an attack in
practice.)
Signed-off-by: Jann Horn <jann@thejh.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs fixes from Al Viro.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
posix_acl: de-union a_refcount and a_rcu
nfs_atomic_open(): prevent parallel nfs_lookup() on a negative hashed
Use the right predicate in ->atomic_open() instances
Pull eCryptfs fixes from Tyler Hicks:
"Provide a more concise fix for CVE-2016-1583:
- Additionally fixes linux-stable regressions caused by the
cherry-picking of the original fix
Some very minor changes that have queued up:
- Fix typos in code comments
- Remove unnecessary check for NULL before destroying kmem_cache"
* tag 'ecryptfs-4.7-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
ecryptfs: don't allow mmap when the lower fs doesn't support it
Revert "ecryptfs: forbid opening files without mmap handler"
ecryptfs: fix spelling mistakes
eCryptfs: fix typos in comment
ecryptfs: drop null test before destroy functions
There are legitimate reasons to disallow mmap on certain files, notably
in sysfs or procfs. We shouldn't emulate mmap support on file systems
that don't offer support natively.
CVE-2016-1583
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: stable@vger.kernel.org
[tyhicks: clean up f_op check by using ecryptfs_file_to_lower()]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
This reverts commit 2f36db7100.
It fixed a local root exploit but also introduced a dependency on
the lower file system implementing an mmap operation just to open a file,
which is a bit of a heavy hammer. The right fix is to have mmap depend
on the existence of the mmap handler instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Pull block IO fixes from Jens Axboe:
"Three small fixes that have been queued up and tested for this series:
- A bug fix for xen-blkfront from Bob Liu, fixing an issue with
incomplete requests during migration.
- A fix for an ancient issue in retrieving the IO priority of a
different PID than self, preventing that task from going away while
we access it. From Omar.
- A writeback fix from Tahsin, fixing a case where we'd call ihold()
with a zero ref count inode"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix use-after-free in sys_ioprio_get()
writeback: inode cgroup wb switch should not call ihold()
xen-blkfront: save uncompleted reqs in blkfront_resume()
Pull configfs fix from Christoph Hellwig:
"A fix from Marek for ppos handling in configfs_write_bin_file, which
was introduced in Linux 4.5, but didn't have any users until recently"
* tag 'configfs-for-4.7' of git://git.infradead.org/users/hch/configfs:
configfs: Remove ppos increment in configfs_write_bin_file
->atomic_open() can be given an in-lookup dentry *or* a negative one
found in dcache. Use d_in_lookup() to tell one from another, rather
than d_unhashed().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Right now when a new overlay inode is created, we initialize overlay
inode's ->i_mode from underlying inode ->i_mode but we retain only
file type bits (S_IFMT) and discard permission bits.
This patch changes it and retains permission bits too. This should allow
overlay to do permission checks on overlay inode itself in task context.
[SzM] It also fixes clearing suid/sgid bits on write.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4bacc9c923 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Before 4bacc9c923 ("overlayfs: Make f_path...") file->f_path pointed to
the underlying file, hence suid/sgid removal on write worked fine.
After that patch file->f_path pointed to the overlay file, and the file
mode bits weren't copied to overlay_inode->i_mode. So the suid/sgid
removal simply stopped working.
The fix is to copy the mode bits, but then ovl_setattr() needs to clear
ATTR_MODE to avoid the BUG() in notify_change(). So do this first, then in
the next patch copy the mode.
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4bacc9c923 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Pull fuse fix from Miklos Szeredi:
"This makes sure userspace filesystems are not broken by the parallel
lookups and readdir feature"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: serialize dirops by default
Pull overlayfs fixes from Miklos Szeredi:
"This contains fixes for a dentry leak, a regression in 4.6 noticed by
Docker users and missing write access checking in truncate"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: warn instead of error if d_type is not supported
ovl: get_write_access() in truncate
ovl: fix dentry leak for default_permissions
overlay needs underlying fs to support d_type. Recently I put in a
patch in to detect this condition and started failing mount if
underlying fs did not support d_type.
But this breaks existing configurations over kernel upgrade. Those who
are running docker (partially broken configuration) with xfs not
supporting d_type, are surprised that after kernel upgrade docker does
not run anymore.
https://github.com/docker/docker/issues/22937#issuecomment-229881315
So instead of erroring out, detect broken configuration and warn
about it. This should allow existing docker setups to continue
working after kernel upgrade.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 45aebeaf4f ("ovl: Ensure upper filesystem supports d_type")
Cc: <stable@vger.kernel.org> 4.6
Pull vfs fixes from Al Viro:
"Tmpfs readdir throughput regression fix (this cycle) + some -stable
fodder all over the place.
One missing bit is Miklos' tonight locks.c fix - NFS folks had already
grabbed that one by the time I woke up ;-)"
[ The locks.c fix came through the nfsd tree just moments ago ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
namespace: update event counter when umounting a deleted dentry
9p: use file_dentry()
ceph: fix d_obtain_alias() misuses
lockless next_positive()
libfs.c: new helper - next_positive()
dcache_{readdir,dir_lseek}(): don't bother with nested ->d_lock
Pull lockd/locks fixes from Bruce Fields:
"One fix for lockd soft lookups in an error path, and one fix for file
leases on overlayfs"
* tag 'nfsd-4.7-3' of git://linux-nfs.org/~bfields/linux:
locks: use file_inode()
lockd: unregister notifier blocks if the service fails to come up completely
Pull libnvdimm fixes from Dan Williams:
"1/ Two regression fixes since v4.6: one for the byte order of a sysfs
attribute (bz121161) and another for QEMU 2.6's NVDIMM _DSM (ACPI
Device Specific Method) implementation that gets tripped up by new
auto-probing behavior in the NFIT driver.
2/ A fix tagged for -stable that stops the kernel from
clobbering/ignoring changes to the configuration of a 'pfn'
instance ("struct page" driver). For example changing the
alignment from 2M to 1G may silently revert to 2M if that value is
currently stored on media.
3/ A fix from Eric for an xfstests failure in dax. It is not
currently tagged for -stable since it requires an 8-exabyte file
system to trigger, and there appear to be no user visible side
effects"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
nfit: fix format interface code byte order
dax: fix offset overflow in dax_io
acpi, nfit: fix acpi_check_dsm() vs zero functions implemented
libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment
(Another one for the f_path debacle.)
ltp fcntl33 testcase caused an Oops in selinux_file_send_sigiotask.
The reason is that generic_add_lease() used filp->f_path.dentry->inode
while all the others use file_inode(). This makes a difference for files
opened on overlayfs since the former will point to the overlay inode the
latter to the underlying inode.
So generic_add_lease() added the lease to the overlay inode and
generic_delete_lease() removed it from the underlying inode. When the file
was released the lease remained on the overlay inode's lock list, resulting
in use after free.
Reported-by: Eryu Guan <eguan@redhat.com>
Fixes: 4bacc9c923 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
- m_start() in fs/namespace.c expects that ns->event is incremented each
time a mount added or removed from ns->list.
- umount_tree() removes items from the list but does not increment event
counter, expecting that it's done before the function is called.
- There are some codepaths that call umount_tree() without updating
"event" counter. e.g. from __detach_mounts().
- When this happens m_start may reuse a cached mount structure that no
longer belongs to ns->list (i.e. use after free which usually leads
to infinite loop).
This change fixes the above problem by incrementing global event counter
before invoking umount_tree().
Change-Id: I622c8e84dcb9fb63542372c5dbf0178ee86bb589
Cc: stable@vger.kernel.org
Signed-off-by: Andrey Ulanov <andreyu@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
v9fs may be used as lower layer of overlayfs and accessing f_path.dentry
can lead to a crash. In this case it's a NULL pointer dereference in
p9_fid_create().
Fix by replacing direct access of file->f_path.dentry with the
file_dentry() accessor, which will always return a native object.
Reported-by: Alessio Igor Bogani <alessioigorbogani@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Alessio Igor Bogani <alessioigorbogani@gmail.com>
Fixes: 4bacc9c923 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If the lockd service fails to start up then we need to be sure that the
notifier blocks are not registered, otherwise a subsequent start of the
service could cause the same notifier to be registered twice, leading to
soft lockups.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0751ddf77b "lockd: Register callbacks on the inetaddr_chain..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Negotiate with userspace filesystems whether they support parallel readdir
and lookup. Disable parallelism by default for fear of breaking fuse
filesystems.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 9902af79c0 ("parallel lookups: actual switch to rwsem")
Fixes: d9b3dbdcfd ("fuse: switch to ->iterate_shared()")
Linus Torvalds
Maxim Patlasov
Jann Horn
Jeff Mahoney
Al Viro
Vivek Goyal
Miklos Szeredi
Andrey Ulanov
Scott Mayhew
Tahsin Erdogan