linux-stable.git/fs, branch v4.4.87

epoll: fix race between ep_poll_callback(POLLFREE) and ep_free()/ep_remove()

2017-09-07T06:34:10+00:00

commit 138e4ad67afd5c6c318b056b4d17c17f2c0ca5c0 upstream.

The race was introduced by me in commit 971316f0503a ("epoll:
ep_unregister_pollwait() can use the freed pwq->whead").  I did not
realize that nothing can protect eventpoll after ep_poll_callback() sets
->whead = NULL, only whead->lock can save us from the race with
ep_free() or ep_remove().

Move ->whead = NULL to the end of ep_poll_callback() and add the
necessary barriers.

TODO: cleanup the ewake/EPOLLEXCLUSIVE logic, it was confusing even
before this patch.

Hopefully this explains use-after-free reported by syzcaller:

	BUG: KASAN: use-after-free in debug_spin_lock_before
	...
	 _raw_spin_lock_irqsave+0x4a/0x60 kernel/locking/spinlock.c:159
	 ep_poll_callback+0x29f/0xff0 fs/eventpoll.c:1148

this is spin_lock(eventpoll->lock),

	...
	Freed by task 17774:
	...
	 kfree+0xe8/0x2c0 mm/slub.c:3883
	 ep_free+0x22c/0x2a0 fs/eventpoll.c:865

Fixes: 971316f0503a ("epoll: ep_unregister_pollwait() can use the freed pwq->whead")
Reported-by: 范龙飞 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

CIFS: remove endian related sparse warning

2017-09-07T06:34:09+00:00

commit 6e3c1529c39e92ed64ca41d53abadabbaa1d5393 upstream.

Recent patch had an endian warning ie
cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()

Signed-off-by: Steve French 
CC: Ronnie Sahlberg 
Acked-by: Pavel Shilovsky 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix maximum SMB2 header size

2017-09-07T06:34:09+00:00

commit 9e37b1784f2be9397a903307574ee565bbadfd75 upstream.

Currently the maximum size of SMB2/3 header is set incorrectly which
leads to hanging of directory listing operations on encrypted SMB3
connections. Fix this by setting the maximum size to 170 bytes that
is calculated as RFC1002 length field size (4) + transform header
size (52) + SMB2 header size (64) + create response size (56).

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Acked-by: Sachin Prabhu 
Signed-off-by: Greg Kroah-Hartman

ceph: fix readpage from fscache

2017-09-07T06:34:09+00:00

commit dd2bc473482eedc60c29cf00ad12568ce40ce511 upstream.

ceph_readpage() unlocks page prematurely prematurely in the case
that page is reading from fscache. Caller of readpage expects that
page is uptodate when it get unlocked. So page shoule get locked
by completion callback of fscache_read_or_alloc_pages()

Signed-off-by: "Yan, Zheng" 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

btrfs: remove duplicate const specifier

2017-09-02T05:06:50+00:00

commit fb75d857a31d600cc0c37b8c7d914014f7fa3f9a upstream.

duplicate const is redundant so remove it

Signed-off-by: Colin Ian King 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

nfsd: Limit end of page list when decoding NFSv4 WRITE

2017-08-30T08:19:25+00:00

commit fc788f64f1f3eb31e87d4f53bcf1ab76590d5838 upstream.

When processing an NFSv4 WRITE operation, argp->end should never
point past the end of the data in the final page of the page list.
Otherwise, nfsd4_decode_compound can walk into uninitialized memory.

More critical, nfsd4_decode_write is failing to increment argp->pagelen
when it increments argp->pagelist.  This can cause later xdr decoders
to assume more data is available than really is, which can cause server
crashes on malformed requests.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()

2017-08-30T08:19:25+00:00

commit d3edede29f74d335f81d95a4588f5f136a9f7dcf upstream.

Add checking for the path component length and verify it is <= the maximum
that the server advertizes via FileFsAttributeInformation.

With this patch cifs.ko will now return ENAMETOOLONG instead of ENOENT
when users to access an overlong path.

To test this, try to cd into a (non-existing) directory on a CIFS share
that has a too long name:
cd /mnt/aaaaaaaaaaaaaaa...

and it now should show a good error message from the shell:
bash: cd: /mnt/aaaaaaaaaaaaaaaa...aaaaaa: File name too long

rh bz 1153996

Signed-off-by: Ronnie Sahlberg 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: Fix df output for users with quota limits

2017-08-30T08:19:25+00:00

commit 42bec214d8bd432be6d32a1acb0a9079ecd4d142 upstream.

The df for a SMB2 share triggers a GetInfo call for
FS_FULL_SIZE_INFORMATION. The values returned are used to populate
struct statfs.

The problem is that none of the information returned by the call
contains the total blocks available on the filesystem. Instead we use
the blocks available to the user ie. quota limitation when filling out
statfs.f_blocks. The information returned does contain Actual free units
on the filesystem and is used to populate statfs.f_bfree. For users with
quota enabled, it can lead to situations where the total free space
reported is more than the total blocks on the system ending up with df
reports like the following

 # df -h /mnt/a
Filesystem         Size  Used Avail Use% Mounted on
//192.168.22.10/a  2.5G -2.3G  2.5G    - /mnt/a

To fix this problem, we instead populate both statfs.f_bfree with the
same value as statfs.f_bavail ie. CallerAvailableAllocationUnits. This
is similar to what is done already in the code for cifs and df now
reports the quota information for the user used to mount the share.

 # df --si /mnt/a
Filesystem         Size  Used Avail Use% Mounted on
//192.168.22.10/a  2.7G  101M  2.6G   4% /mnt/a

Signed-off-by: Sachin Prabhu 
Signed-off-by: Pierguido Lambri 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

pnfs/blocklayout: require 64-bit sector_t

2017-08-16T20:40:30+00:00

commit 8a9d6e964d318533ba3d2901ce153ba317c99a89 upstream.

The blocklayout code does not compile cleanly for a 32-bit sector_t,
and also has no reliable checks for devices sizes, which makes it
unsafe to use with a kernel that doesn't support large block devices.

Signed-off-by: Christoph Hellwig 
Reported-by: Arnd Bergmann 
Fixes: 5c83746a0cf2 ("pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing")
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

nfs/flexfiles: fix leak of nfs4_ff_ds_version arrays

2017-08-16T20:40:28+00:00

commit 1feb26162bee7b2f110facfec71b5c7bdbc7d14d upstream.

The client was freeing the nfs4_ff_layout_ds, but not the contained
nfs4_ff_ds_version array.

Signed-off-by: Weston Andros Adamson 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman