linux-toradex.git/fs/ext4, branch tegra-next

Merge branch 'linux-3.1.y' into android-tegra-nv-3.1

2012-01-24T11:35:20+00:00

Linux 3.1.10

Change-Id: I465d184c492e8041dd0cd90f2cb70fde17ba7118
Signed-off-by: Varun Wadekar

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

Linux 3.1.7

2012-01-05T04:35:50+00:00

Change-Id: I99507d7cfdcee064f808856dc2ce99d806fd864f

ext4: handle EOF correctly in ext4_bio_write_page()

2011-12-21T20:58:34+00:00

commit 5a0dc7365c240795bf190766eba7a27600be3b3e upstream.

We need to zero out part of a page which beyond EOF before setting uptodate,
otherwise, mapread or write will see non-zero data beyond EOF.

Signed-off-by: Yongqiang Yang 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: avoid potential hang in mpage_submit_io() when blocksize < pagesize

2011-12-21T20:58:34+00:00

commit 13a79a4741d37fda2fbafb953f0f301dc007928f upstream.

If there is an unwritten but clean buffer in a page and there is a
dirty buffer after the buffer, then mpage_submit_io does not write the
dirty buffer out.  As a result, da_writepages loops forever.

This patch fixes the problem by checking dirty flag.

Signed-off-by: Yongqiang Yang 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: avoid hangs in ext4_da_should_update_i_disksize()

2011-12-21T20:58:33+00:00

commit ea51d132dbf9b00063169c1159bee253d9649224 upstream.

If the pte mapping in generic_perform_write() is unmapped between
iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the
"copied" parameter to ->end_write can be zero. ext4 couldn't cope with
it with delayed allocations enabled. This skips the i_disksize
enlargement logic if copied is zero and no new data was appeneded to
the inode.

 gdb> bt
 #0  0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\
 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467
 #1  ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\
 xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512
 #2  0xffffffff810d97f1 in generic_perform_write (iocb=, iov=, nr_segs=, pos=0x108000, ppos=0xffff88001e26be40, count=, written=0x0) at mm/filemap.c:2440
 #3  generic_file_buffered_write (iocb=, iov=, nr_segs=, p\
 os=0x108000, ppos=0xffff88001e26be40, count=, written=0x0) at mm/filemap.c:2482
 #4  0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\
 xffff88001e26be40) at mm/filemap.c:2600
 #5  0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=, pos=) at mm/filemap.c:2632
 #6  0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\
 t fs/ext4/file.c:136
 #7  0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=, len=, \
 ppos=0xffff88001e26bf48) at fs/read_write.c:406
 #8  0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 , count=0x4\
 000, pos=0xffff88001e26bf48) at fs/read_write.c:435
 #9  0xffffffff8113816c in sys_write (fd=, buf=0x1ec2960 , count=0x\
 4000) at fs/read_write.c:487
 #10 
 #11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ ()
 #12 0x0000000000000000 in ?? ()
 gdb> print offset
 $22 = 0xffffffffffffffff
 gdb> print idx
 $23 = 0xffffffff
 gdb> print inode->i_blkbits
 $24 = 0xc
 gdb> up
 #1  ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\
 xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512
 2512                    if (ext4_da_should_update_i_disksize(page, end)) {
 gdb> print start
 $25 = 0x0
 gdb> print end
 $26 = 0xffffffffffffffff
 gdb> print pos
 $27 = 0x108000
 gdb> print new_i_size
 $28 = 0x108000
 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize
 $29 = 0xd9000
 gdb> down
 2467            for (i = 0; i < idx; i++)
 gdb> print i
 $30 = 0xd44acbee

This is 100% reproducible with some autonuma development code tuned in
a very aggressive manner (not normal way even for knumad) which does
"exotic" changes to the ptes. It wouldn't normally trigger but I don't
see why it can't happen normally if the page is added to swap cache in
between the two faults leading to "copied" being zero (which then
hangs in ext4). So it should be fixed. Especially possible with lumpy
reclaim (albeit disabled if compaction is enabled) as that would
ignore the young bits in the ptes.

Signed-off-by: Andrea Arcangeli 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: display the correct mount option in /proc/mounts for [no]init_itable

2011-12-21T20:58:33+00:00

commit fc6cb1cda5db7b2d24bf32890826214b857c728e upstream.

/proc/mounts was showing the mount option [no]init_inode_table when
the correct mount option that will be accepted by parse_options() is
[no]init_itable.

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

ext4: fix ext4_end_io_dio() racing against fsync()

2011-12-21T20:58:33+00:00

commit b5a7e97039a80fae673ccc115ce595d5b88fb4ee upstream.

We need to make sure iocb->private is cleared *before* we put the
io_end structure on i_completed_io_list.  Otherwise fsync() could
potentially run on another CPU and free the iocb structure out from
under us.

Reported-by: Kent Overstreet 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'linux-3.1.5' into android-tegra-nv-3.1

2011-12-14T10:03:34+00:00

Conflicts:
	arch/arm/Kconfig

Change-Id: If8aaaf3efcbbf6c9017b38efb6d76ef933f147fa
Signed-off-by: Varun Wadekar

ext4: fix racy use-after-free in ext4_end_io_dio()

2011-12-09T16:54:18+00:00

commit 4c81f045c0bd2cbb78cc6446a4cd98038fe11a2e upstream.

ext4_end_io_dio() queues io_end->work and then clears iocb->private;
however, io_end->work calls aio_complete() which frees the iocb
object.  If that slab object gets reallocated, then ext4_end_io_dio()
can end up clearing someone else's iocb->private, this use-after-free
can cause a leak of a struct ext4_io_end_t structure.

Detected and tested with slab poisoning.

[ Note: Can also reproduce using 12 fio's against 12 file systems with the
  following configuration file:

  [global]
  direct=1
  ioengine=libaio
  iodepth=1
  bs=4k
  ba=4k
  size=128m

  [create]
  filename=${TESTDIR}
  rw=write

  -- tytso ]

Google-Bug-Id: 5354697
Signed-off-by: Tejun Heo 
Signed-off-by: "Theodore Ts'o" 
Reported-by: Kent Overstreet 
Tested-by: Kent Overstreet 
Signed-off-by: Greg Kroah-Hartman