korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-01 08:04:22 +08:00
Code Issues Packages Projects Releases Wiki Activity
69a91c237a
linux/fs
History
Eric Rannaud 69a91c237a fs: allow open(dir, O_TMPFILE|..., 0) with mode 0 
The man page for open(2) indicates that when O_CREAT is specified, the
'mode' argument applies only to future accesses to the file:

	Note that this mode applies only to future accesses of the newly
	created file; the open() call that creates a read-only file
	may well return a read/write file descriptor.

The man page for open(2) implies that 'mode' is treated identically by
O_CREAT and O_TMPFILE.

O_TMPFILE, however, behaves differently:

	int fd = open("/tmp", O_TMPFILE | O_RDWR, 0);
	assert(fd == -1);
	assert(errno == EACCES);

	int fd = open("/tmp", O_TMPFILE | O_RDWR, 0600);
	assert(fd > 0);

For O_CREAT, do_last() sets acc_mode to MAY_OPEN only:

	if (*opened & FILE_CREATED) {
		/* Don't check for write permission, don't truncate */
		open_flag &= ~O_TRUNC;
		will_truncate = false;
		acc_mode = MAY_OPEN;
		path_to_nameidata(path, nd);
		goto finish_open_created;
	}

But for O_TMPFILE, do_tmpfile() passes the full op->acc_mode to
may_open().

This patch lines up the behavior of O_TMPFILE with O_CREAT. After the
inode is created, may_open() is called with acc_mode = MAY_OPEN, in
do_tmpfile().

A different, but related glibc bug revealed the discrepancy:
https://sourceware.org/bugzilla/show_bug.cgi?id=17523

The glibc lazily loads the 'mode' argument of open() and openat() using
va_arg() only if O_CREAT is present in 'flags' (to support both the 2
argument and the 3 argument forms of open; same idea for openat()).
However, the glibc ignores the 'mode' argument if O_TMPFILE is in
'flags'.

On x86_64, for open(), it magically works anyway, as 'mode' is in
RDX when entering open(), and is still in RDX on SYSCALL, which is where
the kernel looks for the 3rd argument of a syscall.

But openat() is not quite so lucky: 'mode' is in RCX when entering the
glibc wrapper for openat(), while the kernel looks for the 4th argument
of a syscall in R10. Indeed, the syscall calling convention differs from
the regular calling convention in this respect on x86_64. So the kernel
sees mode = 0 when trying to use glibc openat() with O_TMPFILE, and
fails with EACCES.

Signed-off-by: Eric Rannaud <e@nanocritical.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-30 15:50:13 -07:00
..
9p 9p: switch to %p[dD] 2014-10-09 02:39:04 -04:00
adfs adfs: add __printf verification, fix format/argument mismatches 2014-08-08 15:57:24 -07:00
affs fs/affs: remove redundant sys_tz declarations 2014-10-14 02:18:22 +02:00
afs Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
autofs4 autofs4: d_manage() should return -EISDIR when appropriate in rcu-walk mode. 2014-10-14 02:18:16 +02:00
befs fs/befs/btree.c: remove typedef befs_btree_node 2014-10-14 02:18:20 +02:00
bfs fs/bfs: use bfs prefix for dump_imap 2014-08-08 15:57:24 -07:00
btrfs vfs: export check_sticky() 2014-10-24 00:14:36 +02:00
cachefiles FS-Cache fixes 2014-10-14 08:40:15 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2014-10-15 06:46:01 +02:00
cifs [CIFS] Remove obsolete comment 2014-10-17 17:17:12 -05:00
coda fs/coda: use linux/uaccess.h 2014-08-08 15:57:20 -07:00
configfs fs/configfs: use pr_fmt 2014-06-04 16:53:53 -07:00
cramfs fs/cramfs/inode.c: use linux/uaccess.h 2014-08-08 15:57:25 -07:00
debugfs fs: debugfs: remove trailing whitespace 2014-07-09 16:58:21 -07:00
devpts fs/devpts/inode.c: convert printk to pr_foo() 2014-06-06 16:08:14 -07:00
dlm dlm: fix missing endian conversion of rcom_status flags 2014-10-14 15:11:48 -05:00
ecryptfs fs: limit filesystem stacking depth 2014-10-24 00:14:39 +02:00
efivarfs fs/efivarfs/super.c: use static const for dentry_operations 2014-06-04 16:54:14 -07:00
efs fs/efs/namei.c: return is not a function 2014-08-08 15:57:18 -07:00
exofs Boaz Harrosh - Fix broken email address 2014-10-19 20:22:32 +03:00
exportfs fs/exportfs/expfs.c: kernel-doc warning fixes 2014-06-04 16:54:14 -07:00
ext2 percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-10-11 08:02:31 -04:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-10-26 11:19:18 -07:00
f2fs f2fs: support volatile operations for transient data 2014-10-07 11:54:41 -07:00
fat fat: remove redundant sys_tz declaration 2014-10-14 02:18:20 +02:00
freevxfs
fscache fs/fscache/object-list.c: use __seq_open_private() 2014-10-13 17:52:21 +01:00
fuse vfs: Make d_invalidate return void 2014-10-09 02:38:57 -04:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-10-13 11:28:42 +02:00
hfs fs/hfs/hfs_fs.h: remove redundant sys_tz declaration 2014-10-14 02:18:20 +02:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
hostfs hostfs: support rename flags 2014-08-07 14:40:09 -04:00
hpfs fs/hpfs/dnode.c: fix suspect code indent 2014-08-08 15:57:22 -07:00
hppfs
hugetlbfs fs/hugetlbfs/inode.c: remove null test before kfree 2014-06-04 16:54:11 -07:00
isofs isofs: replace strnicmp with strncasecmp 2014-10-14 02:18:24 +02:00
jbd jbd/jbd2: use non-movable memory for the jbd superblock 2014-09-04 22:36:35 -04:00
jbd2 jbd2: simplify calling convention around __jbd2_journal_clean_checkpoint_list 2014-09-18 00:58:12 -04:00
jffs2 [jffs2] kill wbuf_queued/wbuf_dwork_lock 2014-10-09 02:39:01 -04:00
jfs Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
kernfs vfs: Remove unnecessary calls of check_submounts_and_drop 2014-10-09 02:38:56 -04:00
lockd File locking related changes for v3.18 (pile #1) 2014-10-11 13:21:34 -04:00
logfs fs/logfs/readwrite.c: kernel-doc warning fixes 2014-08-06 18:01:12 -07:00
minix minix zmap block counts calculation fix 2014-08-08 15:57:20 -07:00
ncpfs fs/ncpfs/dir.c: remove redundant sys_tz declaration 2014-10-14 02:18:16 +02:00
nfs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2014-10-21 12:53:45 -07:00
nfs_common lockd: move lockd's grace period handling into its own module 2014-09-17 16:33:11 -04:00
nfsd nfsd4: fix crash on unknown operation number 2014-10-23 13:39:51 -04:00
nilfs2 nilfs2: improve the performance of fdatasync() 2014-10-14 02:18:20 +02:00
nls
notify fsnotify: next_i is freed during fsnotify_unmount_inodes. 2014-10-29 16:33:14 -07:00
ntfs NTFS: Bump version to 2.1.31. 2014-10-16 12:53:35 +01:00
ocfs2 ocfs2: fix d_splice_alias() return code checking 2014-10-29 16:33:15 -07:00
omfs FS/OMFS: block number sanity check during fill_super operation 2014-10-14 02:18:22 +02:00
openpromfs
overlayfs overlayfs: embed middle into overlay_readdir_data 2014-10-24 20:25:23 -04:00
proc mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared 2014-10-14 02:18:28 +02:00
pstore pstore: Fix duplicate {console,ftrace}-efi entries 2014-10-15 13:51:33 -07:00
qnx4
qnx6 fs/qnx6: update debugging to current functions 2014-08-08 15:57:26 -07:00
quota percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
ramfs fs/ramfs/file-nommu.c: replace count*size kzalloc by kcalloc 2014-08-08 15:57:18 -07:00
reiserfs fs/reiserfs/journal.c: fix sparse context imbalance warning 2014-10-14 02:18:20 +02:00
romfs fs/romfs/super.c: add blank line after declarations 2014-08-08 15:57:25 -07:00
squashfs fs/squashfs/super.c: logging cleanup 2014-08-06 18:01:13 -07:00
sysfs kernfs: move the last knowledge of sysfs out from kernfs 2014-06-03 08:11:18 -07:00
sysv
ubifs UBIFS: Fix trivial typo in power_cut_emulated() 2014-09-30 09:29:44 +03:00
udf udf: Fix loading of special inodes 2014-10-09 13:06:14 +02:00
ufs fs/ufs/balloc.c: remove unused variable 2014-10-14 02:18:20 +02:00
xfs Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
aio.c percpu_ref: add PERCPU_REF_INIT_* flags 2014-09-24 13:31:50 -04:00
anon_inodes.c
attr.c fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-10 13:57:22 -07:00
bad_inode.c bad_inode: add ->rename2() 2014-08-07 14:40:09 -04:00
binfmt_aout.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
binfmt_elf_fdpic.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
binfmt_elf.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
binfmt_em86.c
binfmt_flat.c fs/binfmt_flat.c: make old_reloc() static 2014-06-04 16:54:21 -07:00
binfmt_misc.c binfmt_misc: work around gcc-4.9 warning 2014-10-14 02:18:16 +02:00
binfmt_script.c
binfmt_som.c
block_dev.c Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
buffer.c fs: clarify rate limit suppressed buffer I/O errors 2014-10-21 13:55:11 -06:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Bluetooth: Move HCI socket definitions into its own header file 2014-07-11 13:53:04 +03:00
compat.c vfs: move getname() from callers to do_mount() 2014-10-09 02:39:16 -04:00
coredump.c coredump: add %i/%I in core_pattern to report the tid of the crashed thread 2014-10-14 02:18:21 +02:00
dcache.c fix inode leaks on d_splice_alias() failure exits 2014-10-23 22:30:18 -04:00
dcookies.c
direct-io.c fuse: honour max_read and max_write in direct_io mode 2014-09-26 21:16:51 -04:00
drop_caches.c fs: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
eventfd.c
eventpoll.c eventpoll: fix uninitialized variable in epoll_ctl 2014-09-10 15:42:12 -07:00
exec.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
fcntl.c security: make security_file_set_fowner, f_setown and __f_setown void return 2014-09-09 16:01:36 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-10-13 11:28:42 +02:00
file.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:44:12 +02:00
filesystems.c
fs_pin.c make fs/{namespace,super}.c forget about acct.h 2014-08-07 14:40:09 -04:00
fs_struct.c
fs-writeback.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
inode.c mm: allow drivers to prevent new writable mappings 2014-08-08 15:57:31 -07:00
internal.h vfs: export __inode_permission() to modules 2014-10-24 00:14:35 +02:00
ioctl.c
Kconfig overlay filesystem 2014-10-24 00:14:38 +02:00
Kconfig.binfmt
libfs.c locks: plumb a "priv" pointer into the setlease routines 2014-10-07 14:06:12 -04:00
locks.c locks: flock_make_lock should return a struct file_lock (or PTR_ERR) 2014-10-07 14:06:13 -04:00
Makefile overlay filesystem 2014-10-24 00:14:38 +02:00
mbcache.c fs/mbcache: replace __builtin_log2() with ilog2() 2014-06-25 22:08:29 -04:00
mount.h vfs: Add a function to lazily unmount all mounts from any dentry. 2014-10-09 02:38:55 -04:00
mpage.c vfs: guard end of device for mpage interface 2014-10-09 22:25:53 -04:00
namei.c fs: allow open(dir, O_TMPFILE|..., 0) with mode 0 2014-10-30 15:50:13 -07:00
namespace.c vfs: introduce clone_private_mount() 2014-10-24 00:14:36 +02:00
no-block.c
open.c vfs: add i_op->dentry_open() 2014-10-24 00:14:35 +02:00
pipe.c
pnode.c get rid of propagate_umount() mistakenly treating slaves as busy. 2014-08-30 18:31:41 -04:00
pnode.h
posix_acl.c
proc_namespace.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
read_write.c cachefiles_write_page(): switch to __kernel_write() 2014-10-09 02:39:05 -04:00
readdir.c fanotify: create FAN_ACCESS event for readdir 2014-06-04 16:53:52 -07:00
select.c
seq_file.c fs/seq_file: fallback to vmalloc allocation 2014-07-03 09:21:54 -07:00
signalfd.c
splice.c vfs: export do_splice_direct() to modules 2014-10-24 00:14:35 +02:00
stack.c fs: fix comment for 'CONFIG_LBADF' 2014-08-26 09:35:56 +02:00
stat.c
statfs.c
super.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-10-13 11:28:42 +02:00
sync.c Export sync_filesystem() for modular ->remount_fs() use 2014-09-05 08:16:21 -07:00
timerfd.c timerfd: Remove an always true check 2014-08-27 11:17:48 +02:00
utimes.c
xattr.c vfs: Deduplicate code shared by xattr system calls operating on paths 2014-10-12 17:09:10 -04:00