linux/fs
Eric W. Biederman 311fc65c9f pty: Repair TIOCGPTPEER
The implementation of TIOCGPTPEER has two issues.

When /dev/ptmx (as opposed to /dev/pts/ptmx) is opened the wrong
vfsmount is passed to dentry_open.  Which results in the kernel displaying
the wrong pathname for the peer.

The second is simply by caching the vfsmount and dentry of the peer it leaves
them open, in a way they were not previously Which because of the inreased
reference counts can cause unnecessary behaviour differences resulting in
regressions.

To fix these move the ioctl into tty_io.c at a generic level allowing
the ioctl to have access to the struct file on which the ioctl is
being called.  This allows the path of the slave to be derived when
opening the slave through TIOCGPTPEER instead of requiring the path to
the slave be cached.  Thus removing the need for caching the path.

A new function devpts_ptmx_path is factored out of devpts_acquire and
used to implement a function devpts_mntget.   The new function devpts_mntget
takes a filp to perform the lookup on and fsi so that it can confirm
that the superblock that is found by devpts_ptmx_path is the proper superblock.

v2: Lots of fixes to make the code actually work
v3: Suggestions by Linus
    - Removed the unnecessary initialization of filp in ptm_open_peer
    - Simplified devpts_ptmx_path as gotos are no longer required

[ This is the fix for the issue that was reverted in commit
  143c97cc65, but this time without breaking 'pbuilder' due to
  increased reference counts   - Linus ]

Fixes: 54ebbfb160 ("tty: add TIOCGPTPEER ioctl")
Reported-by: Christian Brauner <christian.brauner@canonical.com>
Reported-and-tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-24 13:23:03 -07:00
..
9p 9p: Implement show_options 2017-07-11 06:08:58 -04:00
adfs
affs affs: Implement show_options 2017-07-11 06:06:17 -04:00
afs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
autofs4 Fix up over-eager 'wait_queue_t' renaming 2017-07-10 11:40:19 -07:00
befs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
bfs bfs: fix sanity checks for empty files 2017-07-12 16:26:00 -07:00
btrfs Merge branch 'for-4.13-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 2017-07-28 12:26:59 -07:00
cachefiles sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
ceph ceph: fix race in concurrent readdir 2017-07-17 14:54:59 +02:00
cifs Add wait_for_random_bytes() and get_random_*_wait() functions so that 2017-07-15 12:44:02 -07:00
coda fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
configfs configfs: Introduce config_item_get_unless_zero() 2017-06-12 13:20:20 +02:00
cramfs
crypto The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
debugfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
devpts pty: Repair TIOCGPTPEER 2017-08-24 13:23:03 -07:00
dlm
ecryptfs ecryptfs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
efivarfs VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
efs
exofs mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
exportfs
ext2 ext2: preserve i_mode if ext2_set_acl() fails 2017-07-18 11:23:56 +02:00
ext4 ext4: add missing xattr hash update 2017-08-14 08:30:06 -04:00
f2fs f2fs: avoid cpu lockup 2017-07-17 19:23:18 -07:00
fat
freevxfs
fscache
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2017-08-11 11:20:48 -07:00
gfs2 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
hfs fs: semove set but not checked AOP_FLAG_UNINTERRUPTIBLE flag 2017-05-08 17:15:14 -07:00
hfsplus hfsplus: Don't clear SGID when inheriting ACLs 2017-07-18 18:23:39 +02:00
hostfs
hpfs
hugetlbfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
isofs isofs: Fix off-by-one in 'session' mount option parsing 2017-07-18 12:33:16 +02:00
jbd2 Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
jffs2 jffs2: fix spelling mistake: "requestied" -> "requested" 2017-04-19 11:35:55 -07:00
jfs JFS fixes for 4.13 2017-07-25 08:51:57 -07:00
kernfs
lockd sunrpc: mark all struct svc_version instances as const 2017-07-13 15:58:03 -04:00
minix Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
ncpfs mm: per-cgroup memory reclaim stats 2017-07-06 16:24:35 -07:00
nfs Some more NFS client bugfixes for 4.13 2017-08-11 13:54:09 -07:00
nfs_common
nfsd nfsd: Fix a memory scribble in the callback channel 2017-07-17 13:15:06 -04:00
nilfs2 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 13:08:04 -07:00
nls
notify dentry name snapshots 2017-07-07 20:09:10 -04:00
ntfs ntfs: Use ERR_CAST() to avoid cross-structure cast 2017-05-28 10:11:48 -07:00
ocfs2 ocfs2: don't clear SGID when inheriting ACLs 2017-08-02 17:16:13 -07:00
omfs omfs: Implement show_options 2017-07-06 03:31:46 -04:00
openpromfs
orangefs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
overlayfs ovl: check for bad and whiteout index on lookup 2017-07-20 11:08:21 +02:00
proc mm: fix KSM data corruption 2017-08-10 15:54:07 -07:00
pstore Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
qnx4
qnx6
quota quota: correct space limit check 2017-08-07 16:51:28 +02:00
ramfs ramfs: Implement show_options 2017-07-06 03:31:46 -04:00
reiserfs reiserfs: preserve i_mode if __reiserfs_set_acl() fails 2017-07-18 11:24:08 +02:00
romfs
squashfs
sysfs
sysv mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
tracefs VFS: Don't use save/replace_mount_options if not using generic_show_options 2017-07-06 03:31:46 -04:00
ubifs ubifs: Set double hash cookie also for RENAME_EXCHANGE 2017-07-14 22:50:57 +02:00
udf udf: Convert udf_disk_stamp_to_time() to use mktime64() 2017-06-14 11:21:02 +02:00
ufs Writeback error handling fixes (pile #1) 2017-07-07 18:39:15 -07:00
xfs xfs: don't leak quotacheck dquots when cow recovery 2017-08-17 12:40:33 -07:00
aio.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks 2017-08-16 20:32:02 +02:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: Use %u to format u32 2017-07-16 09:24:05 -07:00
binfmt_misc.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
binfmt_script.c
block_dev.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
buffer.c fs/buffer.c: make bh_lru_install() more efficient 2017-07-10 16:32:30 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'work.__copy_in_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:15:02 -07:00
compat.c
coredump.c
dax.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
dcache.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
dcookies.c
direct-io.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
drop_caches.c
eventfd.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
eventpoll.c kcmp: fs/epoll: wrap kcmp code with CONFIG_CHECKPOINT_RESTORE 2017-07-12 16:26:01 -07:00
exec.c exec: Limit arg stack to at most 75% of _STK_LIM 2017-07-07 20:05:08 -07:00
fcntl.c vfs: fix flock compat thinko 2017-07-07 13:48:18 -07:00
fhandle.c
file_table.c fs: new infrastructure for writeback error handling and reporting 2017-07-06 07:02:25 -04:00
file.c fs/file.c: replace alloc_fdmem() with kvmalloc() alternative 2017-07-06 16:24:30 -07:00
filesystems.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
fs_pin.c sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
fs_struct.c
fs-writeback.c writeback: rework wb_[dec|inc]_stat family of functions 2017-07-12 16:26:05 -07:00
inode.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
ioctl.c
iomap.c iomap: fix integer truncation issues in the zeroing and dirtying helpers 2017-08-11 16:56:33 -07:00
Kconfig fs/Kconfig: kill CONFIG_PERCPU_RWSEM some more 2017-07-12 16:26:00 -07:00
Kconfig.binfmt
libfs.c fs: convert __generic_file_fsync to use errseq_t based reporting 2017-07-06 07:02:29 -04:00
locks.c fs/locks: pass kernel struct flock to fcntl_getlk/setlk 2017-05-27 06:07:19 -04:00
Makefile
mbcache.c ext4: xattr inode deduplication 2017-06-22 11:44:55 -04:00
mount.h Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
mpage.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
namei.c Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
namespace.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
no-block.c
nsfs.c VFS: Provide empty name qstr 2017-07-06 03:27:09 -04:00
open.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
pipe.c VFS: Provide empty name qstr 2017-07-06 03:27:09 -04:00
pnode.c mnt: Make propagate_umount less slow for overlapping mount propagation trees 2017-05-23 08:41:17 -05:00
pnode.h
posix_acl.c
proc_namespace.c
read_write.c Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-07 21:48:15 -07:00
readdir.c
select.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 20:57:13 -07:00
seq_file.c mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
signalfd.c sched/wait: Rename wait_queue_t => wait_queue_entry_t 2017-06-20 12:18:27 +02:00
splice.c fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
stack.c
stat.c ufs: restore maintaining ->i_blocks 2017-06-09 16:28:01 -04:00
statfs.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
super.c VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
sync.c fs: remove call_fsync helper function 2017-07-05 18:44:23 -04:00
timerfd.c timerfd: Use get_itimerspec64() and put_itimerspec64() 2017-06-30 04:14:38 -04:00
userfaultfd.c userfaultfd: replace ENOSPC with ESRCH in case mm has gone during copy/zeropage 2017-08-10 15:54:07 -07:00
utimes.c
xattr.c treewide: use kv[mz]alloc* rather than opencoded variants 2017-05-08 17:15:13 -07:00