linux/fs
Dave Chinner 43feeea88c xfs: zero length symlinks are not valid
A log recovery failure has been reproduced where a symlink inode has
a zero length in extent form. It was caused by a shutdown during a
combined fstress+fsmark workload.

The underlying problem is the issue in xfs_inactive_symlink(): the
inode is unlocked between the symlink inactivation/truncation and
the inode being freed. This opens a window for the inode to be
written to disk before it xfs_ifree() removes it from the unlinked
list, marks it free in the inobt and zeros the mode.

For shortform inodes, the fix is simple. xfs_ifree() clears the data
fork state, so there's no need to do it in xfs_inactive_symlink().
This means the shortform fork verifier will not see a zero length
data fork as it mirrors the inode size through to xfs_ifree()), and
hence if the inode gets written back and the fork verifiers are run
they will still see a fork that matches the on-disk inode size.

For extent form (remote) symlinks, it is a little more tricky. Here
we explicitly set the inode size to zero, so the above race can lead
to zero length symlinks on disk. Because the inode is unlinked at
this point (i.e. on the unlinked list) and unreferenced, it can
never be seen again by a user. Hence when we set the inode size to
zeor, also change the type to S_IFREG. xfs_ifree() expects S_IFREG
inodes to be of zero length, and so this avoids all the problems of
zero length symlinks ever hitting the disk. It also avoids the
problem of needing to handle zero length symlink inodes in log
recovery to replay the extent free intents and the remaining
deferops to free the extents the symlink used.

Also add a couple of asserts to warn us if zero length symlinks end
up in either the symlink create or inactivation paths.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-12-12 08:47:15 -08:00
..
9p Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-01 19:58:52 -07:00
adfs adfs: use timespec64 for time conversion 2018-08-22 10:52:51 -07:00
affs affs: fix potential memory leak when parsing option 'prefix' 2018-05-28 12:36:41 +02:00
afs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-30 10:47:50 -08:00
autofs Merge branch 'akpm' (patches from Andrew) 2018-08-22 12:34:08 -07:00
befs fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
bfs bfs: add sanity check at bfs_fill_super() 2018-11-03 10:09:38 -07:00
btrfs for-4.20-rc5-tag 2018-12-05 09:58:17 -08:00
cachefiles fscache, cachefiles: remove redundant variable 'cache' 2018-11-30 16:00:58 +00:00
ceph libceph: assume argonaut on the server side 2018-11-08 17:51:11 +01:00
cifs CIFS: Avoid returning EBUSY to upper layer VFS 2018-12-07 00:59:23 -06:00
coda vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
configfs configfs: fix registered group removal 2018-07-17 06:14:07 -07:00
cramfs Make the Cramfs code more robust against filesystem corruptions, 2018-10-30 12:46:25 -07:00
crypto crypto: speck - remove Speck 2018-09-04 11:35:03 +08:00
debugfs Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent" 2018-06-12 20:52:16 -07:00
devpts devpts: Convert to new IDA API 2018-08-21 23:54:17 -04:00
dlm iov_iter: Separate type from direction and use accessor functions 2018-10-24 00:41:07 +01:00
ecryptfs ecryptfs_rename(): verify that lower dentries are still OK after lock_rename() 2018-10-09 23:33:17 -04:00
efivarfs efivars: Call guid_parse() against guid_t type of variable 2018-07-22 14:13:44 +02:00
efs
exofs fs/exofs: only use true/false for asignment of bool type variable 2018-10-18 02:04:59 -04:00
exportfs exportfs: do not read dentry after free 2018-11-23 09:08:17 -05:00
ext2 ext2: fix potential use after free 2018-11-27 10:21:15 +01:00
ext4 A large number of ext4 bug fixes, mostly buffer and memory leaks on 2018-11-11 16:53:02 -06:00
f2fs Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax 2018-10-28 11:35:40 -07:00
fat fat: truncate inode timestamp updates in setattr 2018-10-31 08:54:14 -07:00
freevxfs freevxfs_lookup(): use d_splice_alias() 2018-05-22 14:27:51 -04:00
fscache fscache: fix race between enablement and dropping of object 2018-11-30 15:57:31 +00:00
fuse fuse: fix use-after-free in fuse_direct_IO() 2018-11-09 15:52:17 +01:00
gfs2 Merge tag 'gfs2-4.20.fixes3' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 2018-11-16 11:38:14 -06:00
hfs hfs: do not free node before using 2018-11-30 14:56:14 -08:00
hfsplus hfsplus: do not free node before using 2018-11-30 14:56:14 -08:00
hostfs vfs: discard ATTR_ATTR_FLAG 2018-08-17 16:20:28 -07:00
hpfs hpfs: remove unnecessary checks on the value of r when assigning error code 2018-08-25 12:42:33 -07:00
hugetlbfs mm: zero out the vma in vma_init() 2018-08-22 10:52:44 -07:00
isofs Update email address 2018-09-29 22:47:48 -04:00
jbd2 jbd2: fix use after free in jbd2_log_do_checkpoint() 2018-10-05 18:44:40 -04:00
jffs2 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-10-24 11:22:39 +01:00
jfs jfs: remove redundant dquot_initialize() in jfs_evict_inode() 2018-09-20 09:28:49 -05:00
kernfs mm: zero-seek shrinkers 2018-10-26 16:26:33 -07:00
lockd lockd: fix access beyond unterminated strings in prints 2018-10-29 16:58:04 -04:00
minix minix_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
nfs nfs: don't dirty kernel pages read by direct-io 2018-12-02 09:43:56 -05:00
nfs_common net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
nfsd nfsd: COPY and CLONE operations require the saved filehandle to be set 2018-11-08 12:11:45 -05:00
nilfs2 nilfs2: Use xa_erase_irq 2018-11-05 14:57:05 -05:00
nls
notify fanotify: fix handling of events on child sub-directory 2018-11-08 15:43:48 +01:00
ntfs ntfs: don't open-code ERR_CAST 2018-10-12 22:46:50 -04:00
ocfs2 ocfs2: fix potential use after free 2018-11-30 14:56:15 -08:00
omfs omfs_lookup(): report IO errors, use d_splice_alias() 2018-05-22 14:27:58 -04:00
openpromfs openpromfs: switch to d_splice_alias() 2018-05-22 14:27:57 -04:00
orangefs Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-01 19:58:52 -07:00
overlayfs vfs: rework data cloning infrastructure 2018-11-02 09:33:08 -07:00
proc New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00
pstore pstore fix: 2018-11-30 09:03:15 -08:00
qnx4 qnx4_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
qnx6 qnx6_lookup: switch to d_splice_alias() 2018-05-22 14:27:54 -04:00
quota fs/quota: Fix spectre gadget in do_quotactl 2018-08-22 18:17:48 +02:00
ramfs
reiserfs reiserfs: remove workaround code for GCC 3.x 2018-10-31 08:54:14 -07:00
romfs romfs_lookup: switch to d_splice_alias() 2018-05-22 14:27:55 -04:00
squashfs Squashfs: Compute expected length from inode size rather than block length 2018-08-02 09:34:02 -07:00
sysfs Driver core patches for 4.19-rc1 2018-08-18 11:44:53 -07:00
sysv sysv: return 'err' instead of 0 in __sysv_write_inode 2018-11-10 08:02:40 -05:00
tracefs tracefs: Annotate tracefs_ops with __ro_after_init 2018-07-31 11:32:44 -04:00
ubifs ubifs: Remove unneeded semicolon 2018-10-23 13:49:02 +02:00
udf udf: Allow mounting volumes with incorrect identification strings 2018-11-19 10:27:59 +01:00
ufs fs/ufs: use ktime_get_real_seconds for sb and cg timestamps 2018-08-17 16:20:27 -07:00
xfs xfs: zero length symlinks are not valid 2018-12-12 08:47:15 -08:00
Kconfig autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
Kconfig.binfmt kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
Makefile autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
aio.c aio: fix failure to put the file pointer 2018-11-17 10:05:07 -05:00
anon_inodes.c anon_inode_getfile(): switch to alloc_file_pseudo() 2018-07-12 10:04:27 -04:00
attr.c fs: Fix attr.c kernel-doc 2018-07-03 16:44:45 -04:00
bad_inode.c get rid of 'opened' argument of ->atomic_open() - part 3 2018-07-12 10:04:20 -04:00
binfmt_aout.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_elf.c signal: Distinguish between kernel_siginfo and siginfo 2018-10-03 16:47:43 +02:00
binfmt_elf_fdpic.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
binfmt_em86.c
binfmt_flat.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_misc.c turn filp_clone_open() into inline wrapper for dentry_open() 2018-07-10 23:29:03 -04:00
binfmt_script.c
block_dev.c iov_iter: Use accessor function 2018-10-24 00:40:44 +01:00
buffer.c for-linus-20181102 2018-11-02 11:25:48 -07:00
char_dev.c block, char_dev: Use correct format specifier for unsigned ints 2018-03-15 17:59:24 +01:00
compat.c ncpfs: remove compat functionality 2018-06-05 19:23:26 +02:00
compat_binfmt_elf.c y2038: globally rename compat_time to old_time32 2018-08-27 14:48:48 +02:00
compat_ioctl.c media updates for v4.20-rc1 2018-10-29 14:29:58 -07:00
coredump.c signal: Distinguish between kernel_siginfo and siginfo 2018-10-03 16:47:43 +02:00
d_path.c split d_path() and friends into a separate file 2018-03-29 15:07:46 -04:00
dax.c dax: Fix unlock mismatch with updated API 2018-12-04 21:32:00 -08:00
dcache.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
dcookies.c fs: add do_lookup_dcookie() helper; remove in-kernel call to syscall 2018-04-02 20:15:39 +02:00
direct-io.c fs: fix lost error code in dio_complete 2018-11-30 08:35:14 -07:00
drop_caches.c
eventfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
eventpoll.c fs/eventpoll.c: simplify ep_is_linked() callers 2018-08-22 10:52:49 -07:00
exec.c Revert "exec: make de_thread() freezable" 2018-12-04 16:04:20 +01:00
fcntl.c signal: Distinguish between kernel_siginfo and siginfo 2018-10-03 16:47:43 +02:00
fhandle.c
file.c fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() 2018-04-02 20:16:00 +02:00
file_table.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
filesystems.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
fs-writeback.c fs: Convert writeback to XArray 2018-10-21 10:46:42 -04:00
fs_pin.c
fs_struct.c
inode.c mm: don't reclaim inodes with many attached pages 2018-11-18 10:15:09 -08:00
internal.h overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
ioctl.c vfs: rework data cloning infrastructure 2018-11-02 09:33:08 -07:00
iomap.c iomap: partially revert 4721a60109 (simulated directio short read on EFAULT) 2018-12-04 09:40:02 -08:00
libfs.c fs, dax: prepare for dax-specific address_space_operations 2018-03-30 11:34:55 -07:00
locks.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
mbcache.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
mount.h
mpage.c mpage: mpage_readpages() should submit IO as read-ahead 2018-08-17 16:20:29 -07:00
namei.c namei: allow restricted O_CREAT of FIFOs and regular files 2018-08-23 18:48:43 -07:00
namespace.c mnt: fix __detach_mounts infinite loop 2018-11-12 01:02:34 -06:00
no-block.c
nsfs.c
open.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
pipe.c Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-08-13 19:58:36 -07:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c vfs: allow some remap flags to be passed to vfs_clone_file_range 2018-12-04 08:50:49 -08:00
readdir.c fs: add ksys_getdents64() helper; remove in-kernel calls to sys_getdents64() 2018-04-02 20:16:02 +02:00
select.c y2038: globally rename compat_time to old_time32 2018-08-27 14:48:48 +02:00
seq_file.c fs/seq_file.c: simplify seq_file iteration code and interface 2018-08-17 16:20:28 -07:00
signalfd.c signal: Distinguish between kernel_siginfo and siginfo 2018-10-03 16:47:43 +02:00
splice.c splice: don't read more than available pipe space 2018-12-04 08:50:49 -08:00
stack.c
stat.c y2038: Remove newstat family from default syscall set 2018-08-29 15:42:20 +02:00
statfs.c kernel: add kcompat_sys_{f,}statfs64() 2018-07-12 14:49:48 +01:00
super.c fsnotify: add super block object type 2018-09-03 15:14:01 +02:00
sync.c Changes for this release: 2018-04-04 12:44:02 -07:00
timerfd.c y2038: globally rename compat_time to old_time32 2018-08-27 14:48:48 +02:00
userfaultfd.c userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas 2018-11-30 14:56:14 -08:00
utimes.c y2038: utimes: Rework #ifdef guards for compat syscalls 2018-08-29 15:42:23 +02:00
xattr.c sysfs: Do not return POSIX ACL xattrs via listxattr 2018-09-18 07:30:48 -04:00