linux-stable.git/fs/fuse/dir.c, branch linux-4.7.y

fuse: fix killing s[ug]id in setattr

2016-10-22T10:06:47+00:00

commit a09f99eddef44035ec764075a37bace8181bec38 upstream.

Fuse allowed VFS to set mode in setattr in order to clear suid/sgid on
chown and truncate, and (since writeback_cache) write.  The problem with
this is that it'll potentially restore a stale mode.

The poper fix would be to let the filesystems do the suid/sgid clearing on
the relevant operations.  Possibly some are already doing it but there's no
way we can detect this.

So fix this by refreshing and recalculating the mode.  Do this only if
ATTR_KILL_S[UG]ID is set to not destroy performance for writes.  This is
still racy but the size of the window is reduced.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: invalidate dir dentry after chmod

2016-10-22T10:06:47+00:00

commit 5e2b8828ff3d79aca8c3a1730652758753205b61 upstream.

Without "default_permissions" the userspace filesystem's lookup operation
needs to perform the check for search permission on the directory.

If directory does not allow search for everyone (this is quite rare) then
userspace filesystem has to set entry timeout to zero to make sure
permissions are always performed.

Changing the mode bits of the directory should also invalidate the
(previously cached) dentry to make sure the next lookup will have a chance
of updating the timeout, if needed.

Reported-by: Jean-Pierre André 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: listxattr: verify xattr list

2016-10-22T10:06:47+00:00

commit cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 upstream.

Make sure userspace filesystem is returning a well formed list of xattr
names (zero or more nonzero length, null terminated strings).

[Michael Theall: only verify in the nonzero size case]

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

Use the right predicate in ->atomic_open() instances

2016-07-05T20:02:23+00:00

->atomic_open() can be given an in-lookup dentry *or* a negative one
found in dcache.  Use d_in_lookup() to tell one from another, rather
than d_unhashed().

Signed-off-by: Al Viro

fuse: serialize dirops by default

2016-06-30T11:10:49+00:00

Negotiate with userspace filesystems whether they support parallel readdir
and lookup.  Disable parallelism by default for fear of breaking fuse
filesystems.

Signed-off-by: Miklos Szeredi 
Fixes: 9902af79c01a ("parallel lookups: actual switch to rwsem")
Fixes: d9b3dbdcfd62 ("fuse: switch to ->iterate_shared()")

switch ->setxattr() to passing dentry and inode separately

2016-05-28T00:09:16+00:00

smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64.  Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim 
Tested-by: Casey Schaufler 
Signed-off-by: Al Viro

fuse: switch to ->iterate_shared()

2016-05-02T23:49:31+00:00

Switch dcache pre-seeding on readdir to d_alloc_parallel();
nothing else is needed.

Signed-off-by: Al Viro

->getxattr(): pass dentry and inode as separate arguments

2016-04-11T04:48:00+00:00

Signed-off-by: Al Viro

wrappers for ->i_mutex access

2016-01-22T23:04:28+00:00

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro

switch ->get_link() to delayed_call, kill ->put_link()

2015-12-30T18:01:03+00:00

Signed-off-by: Al Viro