linux-stable.git/fs/afs, branch linux-5.2.y

afs: use correct afs_call_type in yfs_fs_store_opaque_acl2

2019-09-10T09:35:24+00:00

[ Upstream commit 7533be858f5b9a036b9f91556a3ed70786abca8e ]

It seems that 'yfs_RXYFSStoreOpaqueACL2' should be use in
yfs_fs_store_opaque_acl2().

Fixes: f5e4546347bc ("afs: Implement YFS ACL setting")
Signed-off-by: YueHaibing 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Fix possible oops in afs_lookup trace event

2019-09-10T09:35:24+00:00

[ Upstream commit c4c613ff08d92e72bf64a65ec35a2c3aa1cfcd06 ]

The afs_lookup trace event can cause the following:

[  216.576777] BUG: kernel NULL pointer dereference, address: 000000000000023b
[  216.576803] #PF: supervisor read access in kernel mode
[  216.576813] #PF: error_code(0x0000) - not-present page
...
[  216.576913] RIP: 0010:trace_event_raw_event_afs_lookup+0x9e/0x1c0 [kafs]

If the inode from afs_do_lookup() is an error other than ENOENT, or if it
is ENOENT and afs_try_auto_mntpt() returns an error, the trace event will
try to dereference the error pointer as a valid pointer.

Use IS_ERR_OR_NULL to only pass a valid pointer for the trace, or NULL.

Ideally the trace would include the error value, but for now just avoid
the oops.

Fixes: 80548b03991f ("afs: Add more tracepoints")
Signed-off-by: Marc Dionne 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Fix leak in afs_lookup_cell_rcu()

2019-09-10T09:35:24+00:00

[ Upstream commit a5fb8e6c02d6a518fb2b1a2b8c2471fa77b69436 ]

Fix a leak on the cell refcount in afs_lookup_cell_rcu() due to
non-clearance of the default error in the case a NULL cell name is passed
and the workstation default cell is used.

Also put a bit at the end to make sure we don't leak a cell ref if we're
going to be returning an error.

This leak results in an assertion like the following when the kafs module is
unloaded:

	AFS: Assertion failed
	2 == 1 is false
	0x2 == 0x1 is false
	------------[ cut here ]------------
	kernel BUG at fs/afs/cell.c:770!
	...
	RIP: 0010:afs_manage_cells+0x220/0x42f [kafs]
	...
	 process_one_work+0x4c2/0x82c
	 ? pool_mayday_timeout+0x1e1/0x1e1
	 ? do_raw_spin_lock+0x134/0x175
	 worker_thread+0x336/0x4a6
	 ? rescuer_thread+0x4af/0x4af
	 kthread+0x1de/0x1ee
	 ? kthread_park+0xd4/0xd4
	 ret_from_fork+0x24/0x30

Fixes: 989782dcdc91 ("afs: Overhaul cell database management")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Fix missing dentry data version updating

2019-09-06T08:23:14+00:00

[ Upstream commit 9dd0b82ef530cdfe805c9f7079c99e104be59a14 ]

In the in-kernel afs filesystem, the d_fsdata dentry field is used to hold
the data version of the parent directory when it was created or when
d_revalidate() last caused it to be updated.  This is compared to the
->invalid_before field in the directory inode, rather than the actual data
version number, thereby allowing changes due to local edits to be ignored.
Only if the server data version gets bumped unexpectedly (eg. by a
competing client), do we need to revalidate stuff.

However, the d_fsdata field should also be updated if an rpc op is
performed that modifies that particular dentry.  Such ops return the
revised data version of the directory(ies) involved, so we should use that.

This is particularly problematic for rename, since a dentry from one
directory may be moved directly into another directory (ie. mv a/x b/x).
It would then be sporting the wrong data version - and if this is in the
future, for the destination directory, revalidations would be missed,
leading to foreign renames and hard-link deletion being missed.

Fix this by the following means:

 (1) Return the data version number from operations that read the directory
     contents - if they issue the read.  This starts in afs_dir_iterate()
     and is used, ignored or passed back by its callers.

 (2) In afs_lookup*(), set the dentry version to the version returned by
     (1) before d_splice_alias() is called and the dentry published.

 (3) In afs_d_revalidate(), set the dentry version to that returned from
     (1) if an rpc call was issued.  This means that if a parallel
     procedure, such as mkdir(), modifies the directory, we won't
     accidentally use the data version from that.

 (4) In afs_{mkdir,create,link,symlink}(), set the new dentry's version to
     the directory data version before d_instantiate() is called.

 (5) In afs_{rmdir,unlink}, update the target dentry's version to the
     directory data version as soon as we've updated the directory inode.

 (6) In afs_rename(), we need to unhash the old dentry before we start so
     that we don't get afs_d_revalidate() reverting the version change in
     cross-directory renames.

     We then need to set both the old and the new dentry versions the data
     version of the new directory before we call d_move() as d_move() will
     rehash them.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Only update d_fsdata if different in afs_d_revalidate()

2019-09-06T08:23:14+00:00

[ Upstream commit 5dc84855b0fc7e1db182b55c5564fd539d6eff92 ]

In the in-kernel afs filesystem, d_fsdata is set with the data version of
the parent directory.  afs_d_revalidate() will update this to the current
directory version, but it shouldn't do this if it the value it read from
d_fsdata is the same as no lock is held and cmpxchg() is not used.

Fix the code to only change the value if it is different from the current
directory version.

Fixes: 260a980317da ("[AFS]: Add "directory write" support.")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Fix off-by-one in afs_rename() expected data version calculation

2019-09-06T08:23:14+00:00

[ Upstream commit 37c0bbb3326674940e657118306ac52364314523 ]

When afs_rename() calculates the expected data version of the target
directory in a cross-directory rename, it doesn't increment it as it
should, so it always thinks that the target inode is unexpectedly modified
on the server.

Fixes: a58823ac4589 ("afs: Fix application of status and callback to be under same lock")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

fs: afs: Fix a possible null-pointer dereference in afs_put_read()

2019-09-06T08:23:14+00:00

[ Upstream commit a6eed4ab5dd4bfb696c1a3f49742b8d1846a66a0 ]

In afs_read_dir(), there is an if statement on line 255 to check whether
req->pages is NULL:
	if (!req->pages)
		goto error;

If req->pages is NULL, afs_put_read() on line 337 is executed.
In afs_put_read(), req->pages[i] is used on line 195.
Thus, a possible null-pointer dereference may occur in this case.

To fix this possible bug, an if statement is added in afs_put_read() to
check req->pages.

This bug is found by a static analysis tool STCheck written by us.

Fixes: f3ddee8dc4e2 ("afs: Fix directory handling")
Signed-off-by: Jia-Ju Bai 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Fix loop index mixup in afs_deliver_vl_get_entry_by_name_u()

2019-09-06T08:23:14+00:00

[ Upstream commit 4a46fdba449a5cd890271df5a9e23927d519ed00 ]

afs_deliver_vl_get_entry_by_name_u() scans through the vl entry
received from the volume location server and builds a return list
containing the sites that are currently valid.  When assigning
values for the return list, the index into the vl entry (i) is used
rather than the one for the new list (entry->nr_server).  If all
sites are usable, this works out fine as the indices will match.
If some sites are not valid, for example if AFS_VLSF_DONTUSE is
set, fs_mask and the uuid will be set for the wrong return site.

Fix this by using entry->nr_server as the index into the arrays
being filled in rather than i.

This can lead to EDESTADDRREQ errors if none of the returned sites
have a valid fs_mask.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Marc Dionne 
Signed-off-by: David Howells 
Reviewed-by: Jeffrey Altman 
Signed-off-by: Sasha Levin

afs: Fix the CB.ProbeUuid service handler to reply correctly

2019-09-06T08:23:13+00:00

[ Upstream commit 2067b2b3f4846402a040286135f98f46f8919939 ]

Fix the service handler function for the CB.ProbeUuid RPC call so that it
replies in the correct manner - that is an empty reply for success and an
abort of 1 for failure.

Putting 0 or 1 in an integer in the body of the reply should result in the
fileserver throwing an RX_PROTOCOL_ERROR abort and discarding its record of
the client; older servers, however, don't necessarily check that all the
data got consumed, and so might incorrectly think that they got a positive
response and associate the client with the wrong host record.

If the client is incorrectly associated, this will result in callbacks
intended for a different client being delivered to this one and then, when
the other client connects and responds positively, all of the callback
promises meant for the client that issued the improper response will be
lost and it won't receive any further change notifications.

Fixes: 9396d496d745 ("afs: support the CB.ProbeUuid RPC op")
Signed-off-by: David Howells 
Reviewed-by: Jeffrey Altman 
Signed-off-by: Sasha Levin

Merge tag 'afs-fixes-20190620' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2019-06-28T00:34:12+00:00

Pull AFS fixes from David Howells:
"The in-kernel AFS client has been undergoing testing on opendev.org on
one of their mirror machines. They are using AFS to hold data that is
then served via apache, and Ian Wienand had reported seeing oopses,
spontaneous machine reboots and updates to volumes going missing. This
patch series appears to have fixed the problem, very probably due to
patch (2), but it's not 100% certain.

(1) Fix the printing of the "vnode modified" warning to exclude checks
on files for which we don't have a callback promise from the
server (and so don't expect the server to tell us when it
changes).

Without this, for every file or directory for which we still have
an in-core inode that gets changed on the server, we may get a
message logged when we next look at it. This can happen in bulk
if, for instance, someone does "vos release" to update a R/O
volume from a R/W volume and a whole set of files are all changed
together.

We only really want to log a message if the file changed and the
server didn't tell us about it or we failed to track the state
internally.

(2) Fix accidental corruption of either afs_vlserver struct objects or
the the following memory locations (which could hold anything).
The issue is caused by a union that points to two different
structs in struct afs_call (to save space in the struct). The call
cleanup code assumes that it can simply call the cleanup for one
of those structs if not NULL - when it might be actually pointing
to the other struct.

This means that every Volume Location RPC op is going to corrupt
something.

(3) Fix an uninitialised spinlock. This isn't too bad, it just causes
a one-off warning if lockdep is enabled when "vos release" is
called, but the spinlock still behaves correctly.

(4) Fix the setting of i_block in the inode. This causes du, for
example, to produce incorrect results, but otherwise should not be
dangerous to the kernel"

* tag 'afs-fixes-20190620' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Fix setting of i_blocks
afs: Fix uninitialised spinlock afs_volume::cb_break_lock
afs: Fix vlserver record corruption
afs: Fix over zealous "vnode modified" warnings