linux-stable.git/fs, branch v3.18.52

gfs2: remove IS_ERR_VALUE abuse

2017-05-08T05:44:12+00:00

Picked from commit 287980e49ffc0f6d911601e7e352a812ed27768e ("remove lots
of IS_ERR_VALUE abuses") upstream.

The original fix that was backported to 3.18 already addressed the warning
in some configurations, but not in others, leaving us with the same output:

../fs/gfs2/dir.c: In function 'get_first_leaf':
../fs/gfs2/dir.c:768:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
   error = get_leaf(dip, leaf_no, bh_out);
         ^
../fs/gfs2/dir.c: In function 'dir_split_leaf.isra.20':
../fs/gfs2/dir.c:987:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]

This takes the approach that we took in later versions in mainline,
but does not backport the entire patch, as that would be too large
for stable and IIRC caused regressions in other drivers.

Fixes: 9d46d31e9aea ("gfs2: avoid uninitialized variable warning")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

posix_acl: Clear SGID bit when setting file permissions

2017-05-08T05:44:10+00:00

commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jeff Layton 
Signed-off-by: Jan Kara 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

Handle mismatched open calls

2017-05-08T05:44:10+00:00

commit 38bd49064a1ecb67baad33598e3d824448ab11ec upstream.

A signal can interrupt a SendReceive call which result in incoming
responses to the call being ignored. This is a problem for calls such as
open which results in the successful response being ignored. This
results in an open file resource on the server.

The patch looks into responses which were cancelled after being sent and
in case of successful open closes the open fids.

For this patch, the check is only done in SendReceive2()

RH-bz: 1403319

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

timerfd: Protect the might cancel mechanism proper

2017-05-08T05:44:10+00:00

commit 1e38da300e1e395a15048b0af1e5305bd91402f6 upstream.

The handling of the might_cancel queueing is not properly protected, so
parallel operations on the file descriptor can race with each other and
lead to list corruptions or use after free.

Protect the context for these operations with a seperate lock.

The wait queue lock cannot be reused for this because that would create a
lock inversion scenario vs. the cancel lock. Replacing might_cancel with an
atomic (atomic_t or atomic bit) does not help either because it still can
race vs. the actual list operation.

Reported-by: Dmitry Vyukov 
Signed-off-by: Thomas Gleixner 
Cc: "linux-fsdevel@vger.kernel.org"
Cc: syzkaller 
Cc: Al Viro 
Cc: linux-fsdevel@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311521430.3457@nanos
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

nfsd: check for oversized NFSv2/v3 arguments

2017-05-08T05:44:09+00:00

commit e6838a29ecb484c97e4efef9429643b9851fba6e upstream.

A client can append random data to the end of an NFSv2 or NFSv3 RPC call
without our complaining; we'll just stop parsing at the end of the
expected data and ignore the rest.

Encoded arguments and replies are stored together in an array of pages,
and if a call is too large it could leave inadequate space for the
reply.  This is normally OK because NFS RPC's typically have either
short arguments and long replies (like READ) or long arguments and short
replies (like WRITE).  But a client that sends an incorrectly long reply
can violate those assumptions.  This was observed to cause crashes.

Also, several operations increment rq_next_page in the decode routine
before checking the argument size, which can leave rq_next_page pointing
well past the end of the page array, causing trouble later in
svc_free_pages.

So, following a suggestion from Neil Brown, add a central check to
enforce our expectation that no NFSv2/v3 call has both a large call and
a large reply.

As followup we may also want to rewrite the encoding routines to check
more carefully that they aren't running off the end of the page array.

We may also consider rejecting calls that have any extra garbage
appended.  That would be safer, and within our rights by spec, but given
the age of our server and the NFS protocol, and the fact that we've
never enforced this before, we may need to balance that against the
possibility of breaking some oddball client.

Reported-by: Tuomas Haanpää 
Reported-by: Ari Kauppi 
Reviewed-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()

2017-05-08T05:44:07+00:00

commit 9e92f48c34eb2b9af9d12f892e2fe1fce5e8ce35 upstream.

We aren't checking to see if the in-inode extended attribute is
corrupted before we try to expand the inode's extra isize fields.

This can lead to potential crashes caused by the BUG_ON() check in
ext4_xattr_shift_entries().

Signed-off-by: Theodore Ts'o 
Cc: Julia Lawall 
Signed-off-by: Greg Kroah-Hartman

f2fs: do more integrity verification for superblock

2017-05-08T05:44:07+00:00

commit 9a59b62fd88196844cee5fff851bee2cfd7afb6e upstream.

Do more sanity check for superblock during ->mount.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix state->private cast on 32 bit machines

2017-04-30T03:49:16+00:00

commit 6e1103a6e9b19dbdc348077d04a546b626911fc5 upstream.

Suppress the following warning displayed on building 32bit (i686) kernel.

===============================================================================
...
   CC [M]  fs/btrfs/extent_io.o
fs/btrfs/extent_io.c: In function ‘btrfs_free_io_failure_record’:
fs/btrfs/extent_io.c:2193:13: warning: cast to pointer from integer of
different size [-Wint-to-pointer-cast]
    failrec = (struct io_failure_record *)state->private;
...
===============================================================================

Signed-off-by: Satoru Takeuchi 
Reported-by: Chris Murphy 
Signed-off-by: Chris Mason 
Cc: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

gfs2: avoid uninitialized variable warning

2017-04-30T03:49:16+00:00

commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 upstream.

We get a bogus warning about a potential uninitialized variable
use in gfs2, because the compiler does not figure out that we
never use the leaf number if get_leaf_nr() returns an error:

fs/gfs2/dir.c: In function 'get_first_leaf':
fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/gfs2/dir.c: In function 'dir_split_leaf':
fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]

Changing the 'if (!error)' to 'if (!IS_ERR_VALUE(error))' is
sufficient to let gcc understand that this is exactly the same
condition as in IS_ERR() so it can optimize the code path enough
to understand it.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Bob Peterson 
Signed-off-by: Greg Kroah-Hartman

Fix signed/unsigned pointer warning

2017-04-30T03:49:15+00:00

commit 97c7134ae22fbd2b8730211f9d4d4517264a8efe upstream.

Commit 2ae83bf93882d1 ("[CIFS] Fix setting time before epoch (negative
time values)") changed "u64 t" to "s64 t", which makes do_div() complain
about a pointer signedness mismatch:

      CC      fs/cifs/netmisc.o
    In file included from ./arch/mips/include/asm/div64.h:12:0,
                     from include/linux/kernel.h:124,
                     from include/linux/list.h:8,
                     from include/linux/wait.h:6,
                     from include/linux/net.h:23,
                     from fs/cifs/netmisc.c:25:
    fs/cifs/netmisc.c: In function ‘cifs_NTtimeToUnix’:
    include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast [enabled by default]
      (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
                                ^
    fs/cifs/netmisc.c:941:22: note: in expansion of macro ‘do_div’
       ts.tv_nsec = (long)do_div(t, 10000000) * 100;

Introduce a temporary "u64 abs_t" variable to fix this.

Signed-off-by: Kevin Cernekee 
Signed-off-by: Steve French 
Cc: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman