inode->i_private is assigned by a Node pointer only after registering a
new binary format, so it could be NULL if inode was created by
bm_fill_super() (or iput() was called by the error path in
bm_register_write()), and this could result in NULL pointer dereference
when evicting such an inode. e.g. mount binfmt_misc filesystem then
umount it immediately:
mount -t binfmt_misc binfmt_misc /proc/sys/fs/binfmt_misc
umount /proc/sys/fs/binfmt_misc
will result in
BUG: unable to handle kernel NULL pointer dereference at 0000000000000013
IP: bm_evict_inode+0x16/0x40 [binfmt_misc]
...
Call Trace:
evict+0xd3/0x1a0
iput+0x17d/0x1d0
dentry_unlink_inode+0xb9/0xf0
__dentry_kill+0xc7/0x170
shrink_dentry_list+0x122/0x280
shrink_dcache_parent+0x39/0x90
do_one_tree+0x12/0x40
shrink_dcache_for_umount+0x2d/0x90
generic_shutdown_super+0x1f/0x120
kill_litter_super+0x29/0x40
deactivate_locked_super+0x43/0x70
deactivate_super+0x45/0x60
cleanup_mnt+0x3f/0x70
__cleanup_mnt+0x12/0x20
task_work_run+0x86/0xa0
exit_to_usermode_loop+0x6d/0x99
syscall_return_slowpath+0xba/0xf0
entry_SYSCALL_64_fastpath+0xa3/0xa
Fix it by making sure Node (e) is not NULL.
Link: http://lkml.kernel.org/r/20171010100642.31786-1-eguan@redhat.com
Fixes: 83f918274e ("exec: binfmt_misc: shift filp_close(interp_file) from kill_node() to bm_evict_inode()")
Signed-off-by: Eryu Guan <eguan@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull xfs fixes from Darrick Wong:
- Fix a stale kernel memory exposure when logging inodes.
- Fix some build problems with CONFIG_XFS_RT=n
- Don't change inode mode if the acl write fails, leaving the file
totally inaccessible.
- Fix a dangling pointer problem when removing an attr fork under
memory pressure.
- Don't crash while trying to invalidate a null buffer associated with
a corrupt metadata pointer.
* tag 'xfs-4.14-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: handle error if xfs_btree_get_bufs fails
xfs: reinit btree pointer on attr tree inactivation walk
xfs: Fix bool initialization/comparison
xfs: don't change inode mode if ACL update fails
xfs: move more RT specific code under CONFIG_XFS_RT
xfs: Don't log uninitialised fields in inode structures
Pull quota fix from Jan Kara:
"A fix for a regression in handling of quota grace times and warnings"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
quota: Generate warnings for DQUOT_SPACE_NOFAIL allocations
Jason reported that a corrupted filesystem failed to replay
the log with a metadata block out of bounds warning:
XFS (dm-2): _xfs_buf_find: Block out of range: block 0x80270fff8, EOFS 0x9c40000
_xfs_buf_find() and xfs_btree_get_bufs() return NULL if
that happens, and then when xfs_alloc_fix_freelist() calls
xfs_trans_binval() on that NULL bp, we oops with:
BUG: unable to handle kernel NULL pointer dereference at 00000000000000f8
We don't handle _xfs_buf_find errors very well, every
caller higher up the stack gets to guess at why it failed.
But we should at least handle it somehow, so return
EFSCORRUPTED here.
Reported-by: Jason L Tibbitts III <tibbs@math.uh.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
xfs_attr3_root_inactive() walks the attr fork tree to invalidate the
associated blocks. xfs_attr3_node_inactive() recursively descends
from internal blocks to leaf blocks, caching block address values
along the way to revisit parent blocks, locate the next entry and
descend down that branch of the tree.
The code that attempts to reread the parent block is unsafe because
it assumes that the local xfs_da_node_entry pointer remains valid
after an xfs_trans_brelse() and re-read of the parent buffer. Under
heavy memory pressure, it is possible that the buffer has been
reclaimed and reallocated by the time the parent block is reread.
This means that 'btree' can point to an invalid memory address, lead
to a random/garbage value for child_fsb and cause the subsequent
read of the attr fork to go off the rails and return a NULL buffer
for an attr fork offset that is most likely not allocated.
Note that this problem can be manufactured by setting
XFS_ATTR_BTREE_REF to 0 to prevent LRU caching of attr buffers,
creating a file with a multi-level attr fork and removing it to
trigger inactivation.
To address this problem, reinit the node/btree pointers to the
parent buffer after it has been re-read. This ensures btree points
to a valid record and allows the walk to proceed.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
If we get ENOSPC half way through setting the ACL, the inode mode
can still be changed even though the ACL does not exist. Reorder the
operation to only change the mode of the inode if the ACL is set
correctly.
Whilst this does not fix the problem with crash consistency (that requires
attribute addition to be a deferred op) it does prevent ENOSPC and other
non-fatal errors setting an xattr to be handled sanely.
This fixes xfstests generic/449.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Various utility functions and interfaces that iterate internal
devices try to reference the realtime device even when RT support is
not compiled into the kernel.
Make sure this code is excluded from the CONFIG_XFS_RT=n build,
and where appropriate stub functions to return fatal errors if
they ever get called when RT support is not present.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Prevent kmemcheck from throwing warnings about reading uninitialised
memory when formatting inodes into the incore log buffer. There are
several issues here - we don't always log all the fields in the
inode log format item, and we never log the inode the
di_next_unlinked field.
In the case of the inode log format item, this is exacerbated
by the old xfs_inode_log_format structure padding issue. Hence make
the padded, 64 bit aligned version of the structure the one we always
use for formatting the log and get rid of the 64 bit variant. This
means we'll always log the 64-bit version and so recovery only needs
to convert from the unpadded 32 bit version from older 32 bit
kernels.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Pull vfs fixes from Al Viro:
"Fairly old DIO bug caught by Andreas (3.10+) and several slightly
younger blk_rq_map_user_iov() bugs, both on map and copy codepaths
(Vitaly and me)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
bio_copy_user_iov(): don't ignore ->iov_offset
more bio_map_user_iov() leak fixes
fix unbalanced page refcounting in bio_map_user_iov
direct-io: Prevent NULL pointer access in submit_page_section
In the code added to function submit_page_section by commit b1058b981,
sdio->bio can currently be NULL when calling dio_bio_submit. This then
leads to a NULL pointer access in dio_bio_submit, so check for a NULL
bio in submit_page_section before trying to submit it instead.
Fixes xfstest generic/250 on gfs2.
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull nfsd fix from Bruce Fields:
"One fix for a 4.14 regression, and one minor fix to the MAINTAINERs
file. (I was weirdly flattered by the idea that lots of random people
suddenly seemed to think Jeff and I were VFS experts. Turns out it was
just a typo)"
* tag 'nfsd-4.14-1' of git://linux-nfs.org/~bfields/linux:
nfsd4: define nfsd4_secinfo_no_name_release()
MAINTAINERS: associate linux/fs.h with VFS instead of file locking
Pull f2fs fix from Jaegeuk Kim:
"This contains one bug fix which causes a kernel panic during fstrim
introduced in 4.14-rc1"
* tag 'f2fs-for-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
f2fs: fix potential panic during fstrim
Eryu has reported that since commit 7b9ca4c61b "quota: Reduce
contention on dq_data_lock" test generic/233 occasionally fails. This is
caused by the fact that since that commit we don't generate warning and
set grace time for quota allocations that have DQUOT_SPACE_NOFAIL set
(these are for example some metadata allocations in ext4). We need these
allocations to behave regularly wrt warning generation and grace time
setting so fix the code to return to the original behavior.
Reported-and-tested-by: Eryu Guan <eguan@redhat.com>
CC: stable@vger.kernel.org
Fixes: 7b9ca4c61b
Signed-off-by: Jan Kara <jack@suse.cz>
Pull xfs fixes from Darrick Wong:
- fix a race between overlapping copy on write aio
- fix cow fork swapping when we defragment reflinked files
* tag 'xfs-4.14-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: handle racy AIO in xfs_reflink_end_cow
xfs: always swap the cow forks when swapping extents
Pull btrfs fixes from David Sterba:
"Two more fixes for bugs introduced in 4.13.
The sector_t problem with 32bit architecture and !LBDAF config seems
serious but the number of affected deployments is hopefully low.
The clashing status bits could lead to a confusing in-memory state of
the whole-filesystem operations if used with the quota override sysfs
knob"
* 'for-4.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix overlap of fs_info::flags values
btrfs: avoid overflow when sector_t is 32 bit
Pull ceph fixes from Ilya Dryomov:
"Two fixups for CephFS snapshot-handling patches in -rc1"
* tag 'ceph-for-4.14-rc4' of git://github.com/ceph/ceph-client:
ceph: fix __choose_mds() for LSSNAP request
ceph: properly queue cap snap for newly created snap realm
Pull overlayfs fixes from Miklos Szeredi:
"Fix a regression in 4.14 and one in 4.13. The latter is a case when
Docker is doing something it really shouldn't and gets away with it.
We now print a warning instead of erroring out.
There are also fixes to several error paths"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: fix regression caused by exclusive upper/work dir protection
ovl: fix missing unlock_rename() in ovl_do_copy_up()
ovl: fix dentry leak in ovl_indexdir_cleanup()
ovl: fix dput() of ERR_PTR in ovl_cleanup_index()
ovl: fix error value printed in ovl_lookup_index()
ovl: fix may_write_real() for overlayfs directories
Commit 34b1744c91 ("nfsd4: define ->op_release for compound ops")
defined a couple ->op_release functions and run them if necessary.
But there's a problem with that is that it reused
nfsd4_secinfo_release() as the op_release of OP_SECINFO_NO_NAME, and
caused a leak on struct nfsd4_secinfo_no_name in
nfsd4_encode_secinfo_no_name(), because there's no .si_exp field in
struct nfsd4_secinfo_no_name.
I found this because I was unable to umount an ext4 partition after
exporting it via NFS & run fsstress on the nfs mount. A simplified
reproducer would be:
# mount a local-fs device at /mnt/test, and export it via NFS with
# fsid=0 export option (this is required)
mount /dev/sda5 /mnt/test
echo "/mnt/test *(rw,no_root_squash,fsid=0)" >> /etc/exports
service nfs restart
# locally mount the nfs export with all default, note that I have
# nfsv4.1 configured as the default nfs version, because of the
# fsid export option, v4 mount would fail and fall back to v3
mount localhost:/mnt/test /mnt/nfs
# try to umount the underlying device, but got EBUSY
umount /mnt/nfs
service nfs stop
umount /mnt/test <=== EBUSY here
Fixed it by defining a separate nfsd4_secinfo_no_name_release()
function as the op_release method of OP_SECINFO_NO_NAME that
releases the correct nfsd4_secinfo_no_name structure.
Fixes: 34b1744c91 ("nfsd4: define ->op_release for compound ops")
Signed-off-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Enforcing exclusive ownership on upper/work dirs caused a docker
regression: https://github.com/moby/moby/issues/34672.
Euan spotted the regression and pointed to the offending commit.
Vivek has brought the regression to my attention and provided this
reproducer:
Terminal 1:
mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none
merged/
Terminal 2:
unshare -m
Terminal 1:
umount merged
mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none
merged/
mount: /root/overlay-testing/merged: none already mounted or mount point
busy
To fix the regression, I replaced the error with an alarming warning.
With index feature enabled, mount does fail, but logs a suggestion to
override exclusive dir protection by disabling index.
Note that index=off mount does take the inuse locks, so a concurrent
index=off will issue the warning and a concurrent index=on mount will fail.
Documentation was updated to reflect this change.
Fixes: 2cac0c00a6 ("ovl: get exclusive ownership on upper/work dirs")
Cc: <stable@vger.kernel.org> # v4.13
Reported-by: Euan Kemp <euank@euank.com>
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Use the ovl_lock_rename_workdir() helper which requires
unlock_rename() only on lock success.
Fixes: ("fd210b7d67ee ovl: move copy up lock out")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
index dentry was not released when breaking out of the loop
due to index verification error.
Fixes: 415543d5c6 ("ovl: cleanup bad and stale index entries on mount")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
