linux-toradex.git/fs, branch v3.10.9

jbd2: Fix use after free after error in jbd2_journal_dirty_metadata()

2013-08-20T15:43:05+00:00

commit 91aa11fae1cf8c2fd67be0609692ea9741cdcc43 upstream.

When jbd2_journal_dirty_metadata() returns error,
__ext4_handle_dirty_metadata() stops the handle. However callers of this
function do not count with that fact and still happily used now freed
handle. This use after free can result in various issues but very likely
we oops soon.

The motivation of adding __ext4_journal_stop() into
__ext4_handle_dirty_metadata() in commit 9ea7a0df seems to be only to
improve error reporting. So replace __ext4_journal_stop() with
ext4_journal_abort_handle() which was there before that commit and add
WARN_ON_ONCE() to dump stack to provide useful information.

Reported-by: Sage Weil 
Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

Fix TLB gather virtual address range invalidation corner cases

2013-08-20T15:43:05+00:00

commit 2b047252d087be7f2ba088b4933cd904f92e6fce upstream.

Ben Tebulin reported:

 "Since v3.7.2 on two independent machines a very specific Git
  repository fails in 9/10 cases on git-fsck due to an SHA1/memory
  failures.  This only occurs on a very specific repository and can be
  reproduced stably on two independent laptops.  Git mailing list ran
  out of ideas and for me this looks like some very exotic kernel issue"

and bisected the failure to the backport of commit 53a59fc67f97 ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").

That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.

The real bug is that the TLB gather virtual memory range setup is subtly
buggered.  It was introduced in commit 597e1c3580b7 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.

The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB.  And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.

Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.

This makes the patch larger, but conceptually much simpler.  And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.

Ben verified that this fixes his problem.

Reported-bisected-and-tested-by: Ben Tebulin 
Build-testing-by: Stephen Rothwell 
Build-testing-by: Richard Weinberger 
Reviewed-by: Michal Hocko 
Acked-by: Peter Zijlstra 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs/proc/task_mmu.c: fix buffer overflow in add_page_map()

2013-08-20T15:43:02+00:00

commit 8c8296223f3abb142be8fc31711b18a704c0e7d8 upstream.

Recently we met quite a lot of random kernel panic issues after enabling
CONFIG_PROC_PAGE_MONITOR.  After debuggind we found this has something
to do with following bug in pagemap:

In struct pagemapread:

  struct pagemapread {
      int pos, len;
      pagemap_entry_t *buffer;
      bool v2;
  };

pos is number of PM_ENTRY_BYTES in buffer, but len is the size of
buffer, it is a mistake to compare pos and len in add_page_map() for
checking buffer is full or not, and this can lead to buffer overflow and
random kernel panic issue.

Correct len to be total number of PM_ENTRY_BYTES in buffer.

[akpm@linux-foundation.org: document pagemapread.pos and .len units, fix PM_ENTRY_BYTES definition]
Signed-off-by: Yonghua Zheng 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

reiserfs: fix deadlock in umount

2013-08-15T05:59:10+00:00

commit 672fe15d091ce76d6fb98e489962e9add7c1ba4c upstream.

Since remove_proc_entry() started to wait for IO in progress (i.e.
since 2007 or so), the locking in fs/reiserfs/proc.c became wrong;
if procfs read happens between the moment when umount() locks the
victim superblock and removal of /proc/fs/reiserfs//*,
we'll get a deadlock - read will wait for s_umount (in sget(),
called by r_start()), while umount will wait in remove_proc_entry()
for that read to finish, holding s_umount all along.

Fortunately, the same change allows a much simpler race avoidance -
all we need to do is remove the procfs entries in the very beginning
of reiserfs ->kill_sb(); that'll guarantee that pointer to superblock
will remain valid for the duration for procfs IO, so we don't need
sget() to keep the sucker alive.  As the matter of fact, we can
get rid of the home-grown iterator completely, and use single_open()
instead.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)

2013-08-15T05:59:10+00:00

commit 776164c1faac4966ab14418bb0922e1820da1d19 upstream.

debugfs_remove_recursive() is wrong,

1. it wrongly assumes that !list_empty(d_subdirs) means that this
   dir should be removed.

   This is not that bad by itself, but:

2. if d_subdirs does not becomes empty after __debugfs_remove()
   it gives up and silently fails, it doesn't even try to remove
   other entries.

   However ->d_subdirs can be non-empty because it still has the
   already deleted !debugfs_positive() entries.

3. simple_release_fs() is called even if __debugfs_remove() fails.

Suppose we have

	dir1/
		dir2/
			file2
		file1

and someone opens dir1/dir2/file2.

Now, debugfs_remove_recursive(dir1/dir2) succeeds, and dir1/dir2 goes
away.

But debugfs_remove_recursive(dir1) silently fails and doesn't remove
this directory. Because it tries to delete (the already deleted)
dir1/dir2/file2 again and then fails due to "Avoid infinite loop"
logic.

Test-case:

	#!/bin/sh

	cd /sys/kernel/debug/tracing
	echo 'p:probe/sigprocmask sigprocmask' >> kprobe_events
	sleep 1000 < events/probe/sigprocmask/id &
	echo -n >| kprobe_events

	[ -d events/probe ] && echo "ERR!! failed to rm probe"

And after that it is not possible to create another probe entry.

With this patch debugfs_remove_recursive() skips !debugfs_positive()
files although this is not strictly needed. The most important change
is that it does not try to make ->d_subdirs empty, it simply scans
the whole list(s) recursively and removes as much as possible.

Link: http://lkml.kernel.org/r/20130726151256.GC19472@redhat.com

Acked-by: Greg Kroah-Hartman 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

cifs: don't instantiate new dentries in readdir for inodes that need to be revalidated immediately

2013-08-15T05:59:09+00:00

commit 757c4f6260febff982276818bb946df89c1105aa upstream.

David reported that commit c2b93e06 (cifs: only set ops for inodes in
I_NEW state) caused a regression with mfsymlinks. Prior to that patch,
if a mfsymlink dentry was instantiated at readdir time, the inode would
get a new set of ops when it was revalidated. After that patch, this
did not occur.

This patch addresses this by simply skipping instantiating dentries in
the readdir codepath when we know that they will need to be immediately
revalidated. The next attempt to use that dentry will cause a new lookup
to occur (which is basically what we want to happen anyway).

Reported-and-Tested-by: David McBride 
Cc: "Stefan (metze) Metzmacher" 
Cc: Sachin Prabhu 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: extend the buffer length enought for sprintf() using

2013-08-15T05:59:09+00:00

commit 057d6332b24a4497c55a761c83c823eed9e3f23b upstream.

For cifs_set_cifscreds() in "fs/cifs/connect.c", 'desc' buffer length
is 'CIFSCREDS_DESC_SIZE' (56 is less than 256), and 'ses->domainName'
length may be "255 + '\0'".

The related sprintf() may cause memory overflow, so need extend related
buffer enough to hold all things.

It is also necessary to be sure of 'ses->domainName' must be less than
256, and define the related macro instead of hard code number '256'.

Signed-off-by: Chen Gang 
Reviewed-by: Jeff Layton 
Reviewed-by: Shirish Pargaonkar 
Reviewed-by: Scott Lovenberg 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

ext4: flush the extent status cache during EXT4_IOC_SWAP_BOOT

2013-08-15T05:59:09+00:00

commit cde2d7a796f7e895e25b43471ed658079345636d upstream.

Previously we weren't swapping only some of the extent_status LRU
fields during the processing of the EXT4_IOC_SWAP_BOOT ioctl.  The
much safer thing to do is to just completely flush the extent status
tree when doing the swap.

Signed-off-by: "Theodore Ts'o" 
Cc: Zheng Liu 
Signed-off-by: Greg Kroah-Hartman

ext4: fix mount/remount error messages for incompatible mount options

2013-08-15T05:59:09+00:00

commit 6ae6514b33f941d3386da0dfbe2942766eab1577 upstream.

Commit 5688978 ("ext4: improve handling of conflicting mount options")
introduced incorrect messages shown while choosing wrong mount options.

First of all, both cases of incorrect mount options,
"data=journal,delalloc" and "data=journal,dioread_nolock" result in
the same error message.

Secondly, the problem above isn't solved for remount option: the
mismatched parameter is simply ignored.  Moreover, ext4_msg states
that remount with options "data=journal,delalloc" succeeded, which is
not true.

To fix it up, I added a simple check after parse_options() call to
ensure that data=journal and delalloc/dioread_nolock parameters are
not present at the same time.

Signed-off-by: Piotr Sarna 
Acked-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Kyungmin Park 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: allow the mount options nodelalloc and data=journal

2013-08-15T05:59:09+00:00

commit 59d9fa5c2e9086db11aa287bb4030151d0095a17 upstream.

Commit 26092bf ("ext4: use a table-driven handler for mount options")
wrongly disallows the specifying the mount options nodelalloc and
data=journal simultaneously.  This is incorrect; it should have only
disallowed the combination of delalloc and data=journal
simultaneously.

Reported-by: Piotr Sarna 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman