linux-stable.git/fs, branch linux-3.1.y

nfs: fix regression in handling of context= option in NFSv4

2012-01-18T15:31:55+00:00

commit 8a0d551a59ac92d8ff048d6cb29d3a02073e81e8 upstream.

Setting the security context of a NFSv4 mount via the context= mount
option is currently broken. The NFSv4 codepath allocates a parsed
options struct, and then parses the mount options to fill it. It
eventually calls nfs4_remote_mount which calls security_init_mnt_opts.
That clobbers the lsm_opts struct that was populated earlier. This bug
also looks like it causes a small memory leak on each v4 mount where
context= is used.

Fix this by moving the initialization of the lsm_opts into
nfs_alloc_parsed_mount_data. Also, add a destructor for
nfs_parsed_mount_data to make it easier to free all of the allocations
hanging off of it, and to ensure that the security_free_mnt_opts is
called whenever security_init_mnt_opts is.

I believe this regression was introduced quite some time ago, probably
by commit c02d7adf.

Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFSv4: include bitmap in nfsv4 get acl data

2012-01-18T15:31:55+00:00

commit bf118a342f10dafe44b14451a1392c3254629a1f upstream.

The NFSv4 bitmap size is unbounded: a server can return an arbitrary
sized bitmap in an FATTR4_WORD0_ACL request.  Replace using the
nfs4_fattr_bitmap_maxsz as a guess to the maximum bitmask returned by a server
with the inclusion of the bitmap (xdr length plus bitmasks) and the acl data
xdr length to the (cached) acl page data.

This is a general solution to commit e5012d1f "NFSv4.1: update
nfs4_fattr_bitmap_maxsz" and fixes hitting a BUG_ON in xdr_shrink_bufhead
when getting ACLs.

Fix a bug in decode_getacl that returned -EINVAL on ACLs > page when getxattr
was called with a NULL buffer, preventing ACL > PAGE_SIZE from being retrieved.

Signed-off-by: Andy Adamson 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFS - fix recent breakage to NFS error handling.

2012-01-18T15:31:55+00:00

commit 2edb6bc3852c681c0d948245bd55108dc6407604 upstream.

From c6d615d2b97fe305cbf123a8751ced859dca1d5e Mon Sep 17 00:00:00 2001
From: NeilBrown 
Date: Wed, 16 Nov 2011 09:39:05 +1100
Subject: NFS - fix recent breakage to NFS error handling.

commit 02c24a82187d5a628c68edfe71ae60dc135cd178 made a small and
presumably unintended change to write error handling in NFS.

Previously an error from filemap_write_and_wait_range would only be of
interest if nfs_file_fsync did not return an error.  After this commit,
an error from filemap_write_and_wait_range would mean that (the rest of)
nfs_file_fsync would not even be called.

This means that:
 1/ you are more likely to see EIO than e.g. EDQUOT or ENOSPC.
 2/ NFS_CONTEXT_ERROR_WRITE remains set for longer so more writes are
    synchronous.

This patch restores previous behaviour.

Cc: Josef Bacik 
Cc: Jan Kara 
Cc: Al Viro 
Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFSv4.1: fix backchannel slotid off-by-one bug

2012-01-18T15:31:55+00:00

commit 61f2e5106582d02f30b6807e3f9c07463c572ccb upstream.

Signed-off-by: Andy Adamson 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

ext4: fix undefined behavior in ext4_fill_flex_info()

2012-01-18T15:31:52+00:00

commit d50f2ab6f050311dbf7b8f5501b25f0bf64a439b upstream.

Commit 503358ae01b70ce6909d19dd01287093f6b6271c ("ext4: avoid divide by
zero when trying to mount a corrupted file system") fixes CVE-2009-4307
by performing a sanity check on s_log_groups_per_flex, since it can be
set to a bogus value by an attacker.

	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
	groups_per_flex = 1 << sbi->s_log_groups_per_flex;

	if (groups_per_flex < 2) { ... }

This patch fixes two potential issues in the previous commit.

1) The sanity check might only work on architectures like PowerPC.
On x86, 5 bits are used for the shifting amount.  That means, given a
large s_log_groups_per_flex value like 36, groups_per_flex = 1 << 36
is essentially 1 << 4 = 16, rather than 0.  This will bypass the check,
leaving s_log_groups_per_flex and groups_per_flex inconsistent.

2) The sanity check relies on undefined behavior, i.e., oversized shift.
A standard-confirming C compiler could rewrite the check in unexpected
ways.  Consider the following equivalent form, assuming groups_per_flex
is unsigned for simplicity.

	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
	if (groups_per_flex == 0 || groups_per_flex == 1) {

We compile the code snippet using Clang 3.0 and GCC 4.6.  Clang will
completely optimize away the check groups_per_flex == 0, leaving the
patched code as vulnerable as the original.  GCC keeps the check, but
there is no guarantee that future versions will do the same.

Signed-off-by: Xi Wang 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

xfs: fix acl count validation in xfs_acl_from_disk()

2012-01-12T19:33:47+00:00

commit 093019cf1b18dd31b2c3b77acce4e000e2cbc9ce upstream.

Commit fa8b18ed didn't prevent the integer overflow and possible
memory corruption.  "count" can go negative and bypass the check.

Signed-off-by: Xi Wang 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Ben Myers 
Signed-off-by: Greg Kroah-Hartman

xfs: validate acl count

2012-01-12T19:33:46+00:00

commit fa8b18edd752a8b4e9d1ee2cd615b82c93cf8bba upstream.

This prevents in-memory corruption and possible panics if the on-disk
ACL is badly corrupted.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Ben Myers 
Signed-off-by: Greg Kroah-Hartman

udf: Fix deadlock when converting file from in-ICB one to normal one

2012-01-12T19:33:25+00:00

commit d2eb8c359309ec45d6bf5b147303ab8e13be86ea upstream.

During BKL removal in 2.6.38, conversion of files from in-ICB format to normal
format got broken. We call ->writepage with i_data_sem held but udf_get_block()
also acquires i_data_sem thus creating A-A deadlock.

We fix the problem by dropping i_data_sem before calling ->writepage() which is
safe since i_mutex still protects us against any changes in the file. Also fix
pagelock - i_data_sem lock inversion in udf_expand_file_adinicb() by dropping
i_data_sem before calling find_or_create_page().

Reported-by: Matthias Matiak 
Tested-by: Matthias Matiak 
Reviewed-by: Namjae Jeon 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

ext3: Don't warn from writepage when readonly inode is spotted after error

2012-01-12T19:33:21+00:00

commit 33c104d415e92a51aaf638dc3d93920cfa601e5c upstream.

WARN_ON_ONCE(IS_RDONLY(inode)) tends to trip when filesystem hits error and is
remounted read-only. This unnecessarily scares users (well, they should be
scared because of filesystem error, but the stack trace distracts them from the
right source of their fear ;-). We could as well just remove the WARN_ON but
it's not hard to fix it to not trip on filesystem with errors and not use more
cycles in the common case so that's what we do.

Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

reiserfs: Force inode evictions before umount to avoid crash

2012-01-12T19:33:20+00:00

commit a9e36da655e54545c3289b2a0700b5c443de0edd upstream.

This patch fixes a crash in reiserfs_delete_xattrs during umount.

When shrink_dcache_for_umount clears the dcache from
generic_shutdown_super, delayed evictions are forced to disk. If an
evicted inode has extended attributes associated with it, it will
need to walk the xattr tree to locate and remove them.

But since shrink_dcache_for_umount will BUG if it encounters active
dentries, the xattr tree must be released before it's called or it will
crash during every umount.

This patch forces the evictions to occur before generic_shutdown_super
by calling shrink_dcache_sb first. The additional evictions caused
by the removal of each associated xattr file and dir will be automatically
handled as they're added to the LRU list.

CC: reiserfs-devel@vger.kernel.org
Signed-off-by: Jeff Mahoney 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman