linux/fs
Michael Kerrisk c70f844174 [patch for 2.6.26 4/4] vfs: utimensat(): fix write access check for futimens()
The POSIX.1 draft spec for futimens()/utimensat() says:

        Only a process with the effective user ID equal to the
        user ID of the file, *or with write access to the file*,
        or with appropriate privileges may use futimens() or
        utimensat() with a null pointer as the times argument
        or with both tv_nsec fields set to the special value
        UTIME_NOW.

The important piece here is "with write access to the file", and
this matters for futimens(), which deals with an argument that
is a file descriptor referring to the file whose timestamps are
being updated,  The standard is saying that the "writability"
check is based on the file permissions, not the access mode with
which the file is opened.  (This behavior is consistent with the
semantics of FreeBSD's futimes().)  However, Linux is currently
doing the latter -- futimens(fd, times) is a library
function implemented as

       utimensat(fd, NULL, times, 0)

and within the utimensat() implementation we have the code:

                f = fget(dfd);  // dfd is 'fd'
                ...
                if (f) {
                        if (!(f->f_mode & FMODE_WRITE))
                                goto mnt_drop_write_and_out;

The check should instead be based on the file permissions.

Thanks to Miklos for pointing out how to do this check.
Miklos also pointed out a simplification that could be
made to my first version of this patch, since the checks
for the pathname and file descriptor cases can now be
conflated.

Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-06-23 08:43:52 -04:00
..
9p 9p: fix error path during early mount 2008-05-14 19:23:27 -05:00
adfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
affs [PATCH] fix reservation discarding in affs 2008-05-06 13:45:33 -04:00
afs Fix various old email addresses for dwmw2 2008-06-06 11:29:10 -07:00
autofs mount options: fix autofs 2008-02-08 09:22:40 -08:00
autofs4 autofs: path_{get,put}() cleanups 2008-05-01 08:04:01 -07:00
befs byteorder: don't directly include linux/byteorder/generic.h 2008-05-16 12:01:45 -07:00
bfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
cifs Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2008-06-11 09:45:51 -07:00
coda codafs: fix build warning 2008-04-29 08:06:04 -07:00
configfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
cramfs fs: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:16:44 -04:00
debugfs DEBUGFS: Correct location of debugfs API documentation. 2008-04-30 16:52:47 -07:00
devpts devpts: factor out PTY index allocation 2008-04-30 08:29:48 -07:00
dlm dlm: fix plock dev_write return value 2008-05-19 15:37:27 -05:00
ecryptfs eCryptfs: remove unnecessary page decrypt call 2008-06-06 11:29:09 -07:00
efs efs: update error msg to not refer to deleted read_inode() 2008-04-02 15:28:19 -07:00
exportfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
ext2 ext2: retry block allocation if new blocks are allocated from system zone 2008-04-28 08:58:43 -07:00
ext3 ext3: fix online resize bug 2008-06-06 11:29:13 -07:00
ext4 Ext4: Fix online resize block group descriptor corruption 2008-06-20 11:48:48 -04:00
fat fat: relax the permission check of fat_setattr() 2008-06-12 18:05:39 -07:00
freevxfs fs/freevxfs/: proper externs 2008-04-29 08:06:00 -07:00
fuse fuse: fix thinko in max I/O size calucation 2008-06-17 18:08:10 -07:00
gfs2 [GFS2] Prefer strlcpy() over snprintf() 2008-05-12 08:57:11 +01:00
hfs hfs: fix warning with 64k PAGE_SIZE 2008-04-30 08:29:52 -07:00
hfsplus Fix hfsplus oops on image without extents 2008-05-13 08:02:24 -07:00
hostfs uml: fix hostfs tv_usec calculations 2008-02-05 09:44:30 -08:00
hpfs mount options: fix hpfs 2008-02-08 09:22:40 -08:00
hppfs fix hppfs Makefile breakage 2008-05-21 16:55:58 -07:00
hugetlbfs mm: bdi: add separate writeback accounting capability 2008-04-30 08:29:50 -07:00
isofs isofs: fix access to unallocated memory when reading corrupted filesystem 2008-04-30 08:29:33 -07:00
jbd jbd: need to hold j_state_lock to updates to transaction t_state to T_COMMIT 2008-05-14 19:11:14 -07:00
jbd2 jbd2: Fix barrier fallback code to re-lock the buffer head 2008-06-03 22:31:11 -04:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2008-05-01 11:15:28 -07:00
jfs proc: remove proc_root_fs 2008-04-29 08:06:18 -07:00
lockd fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
minix iget: stop the MINIX filesystem from using iget() and read_inode() 2008-02-07 08:42:28 -08:00
msdos fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
ncpfs ncpfs: use get/put_unaligned_* helpers 2008-04-29 08:06:28 -07:00
nfs nfs: make nfs4_drop_state_owner() static 2008-05-16 09:43:31 -07:00
nfs_common
nfsd nfsd: reorder printk in do_probe_callback to avoid use-after-free 2008-05-18 19:13:07 -04:00
nls
ntfs ntfs: le*_add_cpu conversion 2008-05-24 09:56:08 -07:00
ocfs2 ocfs2: Remove ->hangup() from stack glue operations. 2008-06-16 10:46:52 -07:00
openpromfs iget: stop OPENPROMFS from using iget() and read_inode() 2008-02-07 08:42:29 -08:00
partitions fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
proc pagemap: fix large pages in pagemap 2008-06-12 18:05:41 -07:00
qnx4 iget: stop QNX4 from using iget() and read_inode() 2008-02-07 08:42:28 -08:00
ramfs mm: bdi: add separate writeback accounting capability 2008-04-30 08:29:50 -07:00
reiserfs reiserfs: use open_bdev_excl 2008-04-30 08:29:51 -07:00
romfs ROMFS: Fix up an error in iget removal 2008-03-19 18:53:36 -07:00
smbfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
sysfs sysfs: remove error messages for -EEXIST case 2008-05-14 22:34:16 -07:00
sysv sysv: [bl]e*_add_cpu conversion 2008-04-30 08:29:52 -07:00
udf udf: restore UDFFS_DEBUG to being undefined by default 2008-06-16 14:24:36 +02:00
ufs ufs: remove unneeded ufs_put_inode prototype 2008-05-13 08:02:23 -07:00
vfat fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
xfs [XFS] Fix memory corruption with small buffer reads 2008-05-23 18:12:49 +10:00
aio.c uml: activate_mm: remove the dead PF_BORROWED_MM check 2008-06-06 11:36:22 -07:00
anon_inodes.c [PATCH] sanitize anon_inode_getfd() 2008-05-01 13:08:50 -04:00
attr.c
bad_inode.c iget: introduce a function to register iget failure 2008-02-07 08:42:26 -08:00
binfmt_aout.c fs/binfmt_aout.c: use printk_ratelimit() 2008-04-29 08:06:04 -07:00
binfmt_elf_fdpic.c nommu: fix ksize() abuse 2008-06-06 11:29:13 -07:00
binfmt_elf.c Remove last traces of a.out support from ELF loader. 2008-06-16 10:20:57 -07:00
binfmt_em86.c binfmt_misc.c: avoid potential kernel stack overflow 2008-04-29 08:06:04 -07:00
binfmt_flat.c nommu: fix ksize() abuse 2008-06-06 11:29:13 -07:00
binfmt_misc.c binfmt_misc.c: avoid potential kernel stack overflow 2008-04-29 08:06:04 -07:00
binfmt_script.c binfmt_misc.c: avoid potential kernel stack overflow 2008-04-29 08:06:04 -07:00
binfmt_som.c [PATCH] sanitize handling of shared descriptor tables in failing execve() 2008-04-25 09:23:53 -04:00
bio.c docbook: fix bio missing parameter 2008-05-07 18:35:03 +02:00
block_dev.c [PATCH] fix cgroup-inflicted breakage in block_dev.c 2008-06-23 08:30:55 -04:00
buffer.c fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
char_dev.c fs: remove unused fops from struct char_device_struct 2008-04-29 08:06:01 -07:00
compat_binfmt_elf.c x86: compat_binfmt_elf 2008-01-30 13:31:46 +01:00
compat_ioctl.c tty: The big operations rework 2008-04-30 08:29:47 -07:00
compat.c [PATCH] get rid of leak in compat_execve() 2008-05-16 17:23:05 -04:00
dcache.c [patch 2/7] vfs: mountinfo: add seq_file_root() 2008-04-23 00:04:38 -04:00
dcookies.c d_path: Make d_path() use a struct path 2008-02-14 21:17:09 -08:00
direct-io.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
dnotify.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
dquot.c quota: don't call sync_fs() from vfs_quota_off() when there's no quota turn off 2008-05-13 08:02:23 -07:00
drop_caches.c vfs: skip inodes without pages to free in drop_pagecache_sb() 2008-04-29 08:06:05 -07:00
eventfd.c [PATCH] sanitize anon_inode_getfd() 2008-05-01 13:08:50 -04:00
eventpoll.c [PATCH] sanitize anon_inode_getfd() 2008-05-01 13:08:50 -04:00
exec.c Include <asm/a.out.h> in fs/exec.c only for Alpha. 2008-06-16 10:20:57 -07:00
fcntl.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
fifo.c
file_table.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
file.c [PATCH] avoid multiplication overflows and signedness issues for max_fds 2008-05-16 17:22:52 -04:00
filesystems.c
fs-writeback.c fs/fs-writeback.c: make 2 functions static 2008-04-29 08:06:00 -07:00
generic_acl.c
inode.c VFS: fix unused variable warning 2008-05-06 13:13:37 -07:00
inotify_user.c Remove duplicated unlikely() in IS_ERR() 2008-04-29 08:06:25 -07:00
inotify.c inotify: remove debug code 2008-02-06 10:41:07 -08:00
internal.h [PATCH] move a bunch of declarations to fs/internal.h 2008-04-21 23:11:01 -04:00
ioctl.c make vfs_ioctl() static 2008-04-29 08:06:00 -07:00
ioprio.c cfq-iosched: relax IOPRIO_CLASS_IDLE restrictions 2008-01-28 11:38:15 +01:00
Kconfig [S390] System z large page support. 2008-04-30 13:38:47 +02:00
Kconfig.binfmt frv: don't offer BINFMT_FLAT 2008-06-06 11:29:08 -07:00
libfs.c introduce memory_read_from_buffer() 2008-06-06 11:29:11 -07:00
locks.c Add new 'cond_resched_bkl()' helper function 2008-05-11 16:04:48 -07:00
Makefile x86: compat_binfmt_elf Kconfig 2008-01-30 13:31:46 +01:00
mbcache.c vfs: fix possible deadlock in ext2, ext3, ext4 when using xattrs 2008-04-15 19:35:41 -07:00
mpage.c docbook: fix filesystems.tmpl source files 2008-03-03 10:47:13 -08:00
namei.c [PATCH] return to old errno choice in mkdir() et.al. 2008-05-16 17:23:18 -04:00
namespace.c fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
nfsctl.c Introduce path_put() 2008-02-14 21:13:33 -08:00
no-block.c
open.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
pipe.c sys_pipe(): fix file descriptor leaks 2008-05-08 10:46:56 -07:00
pnode.c [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
pnode.h [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
posix_acl.c
quota_v1.c quota: do not allow setting of quota limits to too high values 2008-04-28 08:58:32 -07:00
quota_v2.c quota: le*_add_cpu conversion 2008-04-30 08:29:51 -07:00
quota.c quota: quota core changes for quotaon on remount 2008-04-28 08:58:33 -07:00
read_write.c fs: use loff_t type instead of long long 2008-04-22 15:17:11 -07:00
read_write.h
readdir.c Use mutex_lock_killable in vfs_readdir 2007-12-06 17:39:54 -05:00
select.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
seq_file.c [patch 2/7] vfs: mountinfo: add seq_file_root() 2008-04-23 00:04:38 -04:00
signalfd.c [PATCH] sanitize anon_inode_getfd() 2008-05-01 13:08:50 -04:00
splice.c splice: handle try_to_release_page() failure 2008-05-28 14:49:27 +02:00
stack.c
stat.c Introduce path_put() 2008-02-14 21:13:33 -08:00
super.c make __put_super() static 2008-04-29 08:06:00 -07:00
sync.c vfs: fix unconditional write_super() call in file_fsync() 2008-04-29 08:06:06 -07:00
timerfd.c [PATCH] sanitize anon_inode_getfd() 2008-05-01 13:08:50 -04:00
utimes.c [patch for 2.6.26 4/4] vfs: utimensat(): fix write access check for futimens() 2008-06-23 08:43:52 -04:00
xattr_acl.c
xattr.c xattr: add missing consts to function arguments 2008-04-29 08:06:06 -07:00