linux/fs
Jan Engelhardt 19c561a60f fs/fat/: refine chmod checks
Prohibit mode changes in non-quiet mode that cannot be stored reliably with
the on-disk format.

Suppose a vfat filesystem is mounted with umask=0 and [not-quiet].  Then
all files will have mode 0777.  Trying to change the owner will fail,
because fat does not know about owners or groups.  chmod 0770, on the other
hand, will succeed, even though fat does not know about the permission
triplet [user/group/other].

So this patch changes fat's not-quiet behavior so that only UNIX modes are
accepted that can be mapped lossless between the fat disk format and the
local system.  There is only one attribute, and that is the readonly
attribute, which is mapped to the UNIX write permission bit(s).  chmod 0555
is therefore valid (taking away the +w bits <=> setting the readonly
attribute).  Since chmod 0775 and chmod 0755 is an ambiguous case as to
whether to set or clear the readonly bit, these modes are also denied.

In quiet mode, chmod and chown will continue to "succeed" as they did
before, meaning that a subsequent stat() will temporarily return the new
mode as long as the inode is not reread from disk, and chown will silently
do nothing, not even return the new uid/gid in stat().

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:40:59 -08:00
..
9p 9p: use copy of the options value instead of original 2007-11-06 08:02:53 -06:00
adfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
affs fs: mark nibblemap const 2007-10-17 08:42:47 -07:00
afs vfs: Add 64 bit i_version support 2008-01-28 23:58:27 -05:00
autofs Use task_pid_nr() instead of pid_nr(task_pid()) 2007-10-19 11:53:43 -07:00
autofs4 pid namespaces: round up the API 2007-10-19 11:53:37 -07:00
befs fs/: Spelling fixes 2008-02-03 17:33:42 +02:00
bfs regression: bfs endianness bug 2007-12-05 09:25:20 -08:00
cifs Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
coda coda: convert struct class_device to struct device 2008-01-24 20:40:05 -08:00
configfs configfs: file.c fix possible recursive locking 2008-01-25 15:05:47 -08:00
cramfs fs/cramfs/inode.c: replace hardcoded value with preprocessor constant 2007-10-18 14:37:29 -07:00
debugfs Kobject: convert fs/* from kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
devpts
dlm dlm: static initialization improvements 2008-01-30 11:04:43 -06:00
ecryptfs Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
efs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
exportfs exportfs: update documentation 2007-10-22 08:13:21 -07:00
ext2 ext2: Fix the max file size for ext2 file system. 2008-01-28 23:58:26 -05:00
ext3 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
ext4 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
fat fs/fat/: refine chmod checks 2008-02-06 10:40:59 -08:00
freevxfs fs/: Spelling fixes 2008-02-03 17:33:42 +02:00
fuse Kobject: convert fs/* from kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
gfs2 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
hfs hfs: fix coverity-found null deref 2008-01-17 15:38:58 -08:00
hfsplus Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hostfs uml: fix hostfs tv_usec calculations 2008-02-05 09:44:30 -08:00
hpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hppfs
hugetlbfs hugetlb: allow sticky directory mount option 2008-02-05 09:44:14 -08:00
isofs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
jbd spinlock: lockbreak cleanup 2008-01-30 13:31:20 +01:00
jbd2 spinlock: lockbreak cleanup 2008-01-30 13:31:20 +01:00
jffs2 Typoes: "whith" -> "with" 2008-02-03 15:14:02 +02:00
jfs Spelling fixes: lenght->length 2008-02-03 15:42:53 +02:00
lockd NLM: tear down RPC clients in nlm_shutdown_hosts 2008-02-01 16:42:15 -05:00
minix limit minixfs printks on corrupted dir i_size 2007-10-17 08:42:53 -07:00
msdos
ncpfs vm audit: add VM_DONTEXPAND to mmap for drivers that need it 2008-02-04 07:55:38 -08:00
nfs Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
nfs_common
nfsd Add 64-bit capability support to the kernel 2008-02-05 09:44:20 -08:00
nls sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
ntfs is_vmalloc_addr(): Check if an address is within the vmalloc boundaries 2008-02-05 09:44:14 -08:00
ocfs2 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
openpromfs [SPARC]: Constify function pointer tables. 2008-01-22 18:29:20 -08:00
partitions Kobject: convert fs/* from kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
proc Add 64-bit capability support to the kernel 2008-02-05 09:44:20 -08:00
qnx4 Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
ramfs Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
reiserfs Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
romfs fs/romfs/inode.c: trivial improvements 2007-10-17 08:42:47 -07:00
smbfs deprecate smbfs in favour of cifs 2008-02-05 14:37:15 -08:00
sysfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2008-01-25 17:19:08 -08:00
sysv Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
udf fs/udf/balloc.c: mark a variable as uninitialized_var() 2007-10-17 08:43:00 -07:00
ufs ufs: fix nexstep dir block size 2007-12-05 09:21:18 -08:00
vfat
xfs is_vmalloc_addr(): Check if an address is within the vmalloc boundaries 2008-02-05 09:44:14 -08:00
aio.c core: remove last users of empty FASTCALL macro 2008-01-30 13:31:17 +01:00
anon_inodes.c anon-inodes use open coded atomic_inc for the shared inode 2007-10-17 08:43:00 -07:00
attr.c VFS: make notify_change pass ATTR_KILL_S*ID to setattr operations 2007-10-18 14:37:22 -07:00
bad_inode.c
binfmt_aout.c mm: fix exit_mmap BUG() on a.out binary exit 2007-12-20 07:49:53 -08:00
binfmt_elf_fdpic.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
binfmt_elf.c fs/binfmt_elf.c: spello fix 2008-02-03 18:05:15 +02:00
binfmt_em86.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_flat.c binfmt_flat: warning fixes 2007-10-17 08:42:54 -07:00
binfmt_misc.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_script.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_som.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
bio.c __bio_clone: don't calculate hw/phys segment counts 2008-01-28 10:04:46 +01:00
block_dev.c Driver core: convert block from raw kobjects to core devices 2008-01-24 20:40:36 -08:00
buffer.c bufferhead: revert constructor removal 2008-02-05 09:44:14 -08:00
char_dev.c Kobject: rename kobject_init_ng() to kobject_init() 2008-01-24 20:40:38 -08:00
compat_binfmt_elf.c x86: compat_binfmt_elf 2008-01-30 13:31:46 +01:00
compat_ioctl.c remove __attribute_used__ 2008-01-28 23:21:18 +01:00
compat.c timerfd: new timerfd API 2008-02-05 09:44:07 -08:00
dcache.c dcache: don't expose uninitialized memory in /proc/<pid>/fd/<fd> 2007-10-22 08:13:18 -07:00
dcookies.c Remove fs.h from mm.h 2007-07-29 17:09:29 -07:00
direct-io.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
dnotify.c mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
dquot.c Don't send quota messages repeatedly when hardlimit reached 2007-12-23 12:54:36 -08:00
drop_caches.c invalidate_mapping_pages(): add cond_resched 2007-07-16 09:05:36 -07:00
eventfd.c
eventpoll.c lockdep: annotate epoll 2008-02-05 09:44:07 -08:00
exec.c exec: rework the group exit and fix the race with kill 2008-02-05 09:44:07 -08:00
fcntl.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
fifo.c
file_table.c fs/file_table.c: use list_for_each_entry() instead of list_for_each() 2007-10-19 11:53:38 -07:00
file.c
filesystems.c
fs-writeback.c writeback: speed up writeback of big dirty files 2008-02-05 09:44:19 -08:00
generic_acl.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00
inode.c ext4: Add inode version support in ext4 2008-01-28 23:58:27 -05:00
inotify_user.c change inotifyfs magic as the same magic is used for futexfs 2007-10-17 08:43:00 -07:00
inotify.c [PATCH] new helper - inotify_evict_watch() 2007-10-21 02:37:38 -04:00
internal.h
ioctl.c drop obsolete sys_ioctl export 2007-07-16 09:05:48 -07:00
ioprio.c cfq-iosched: relax IOPRIO_CLASS_IDLE restrictions 2008-01-28 11:38:15 +01:00
Kconfig deprecate smbfs in favour of cifs 2008-02-05 14:37:15 -08:00
Kconfig.binfmt x86: compat_binfmt_elf Kconfig 2008-01-30 13:31:46 +01:00
libfs.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
locks.c pid-namespaces-vs-locks-interaction 2008-02-03 17:51:36 -05:00
Makefile x86: compat_binfmt_elf Kconfig 2008-01-30 13:31:46 +01:00
mbcache.c fs: Fix to correct the mbcache entries counter 2007-10-25 15:18:29 -07:00
mpage.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
namei.c Use access mode instead of open flags to determine needed permissions 2008-01-12 14:47:58 -08:00
namespace.c kobject: convert main fs kobject to use kobject_create 2008-01-24 20:40:13 -08:00
nfsctl.c nfsctl: use vfs_path_lookup 2007-07-19 10:04:45 -07:00
no-block.c
open.c mark sys_open/sys_read exports unused 2007-11-14 18:45:42 -08:00
pipe.c sched: affine sync wakeups 2007-10-15 17:00:19 +02:00
pnode.c
pnode.h [PATCH] new helpers - collect_mounts() and release_collected_mounts() 2007-10-21 02:37:25 -04:00
posix_acl.c
quota_v1.c
quota_v2.c
quota.c [IA64] Fix build failure in fs/quota.c 2007-07-27 15:40:13 -07:00
read_write.c ext4: export iov_shorten from kernel for ext4's use 2008-01-28 23:58:27 -05:00
read_write.h
readdir.c Use mutex_lock_killable in vfs_readdir 2007-12-06 17:39:54 -05:00
select.c fs/select, remove unused macros 2007-10-19 11:53:41 -07:00
seq_file.c [FS] seq_file: Introduce the seq_open_private() 2007-10-10 16:55:33 -07:00
signalfd.c Fix a small number of "memeber" typoes. 2008-02-03 15:12:15 +02:00
splice.c splice: always updated atime in direct splice 2008-02-01 09:26:32 +01:00
stack.c
stat.c
super.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
sync.c
timerfd.c timerfd: new timerfd API 2008-02-05 09:44:07 -08:00
utimes.c VFS: check nanoseconds in utimensat 2007-10-17 08:42:52 -07:00
xattr_acl.c
xattr.c VFS: Reorder vfs_getxattr to avoid unnecessary calls to the LSM 2008-02-05 09:44:20 -08:00