linux-stable.git/fs, branch v3.10.71

x86, mm/ASLR: Fix stack randomization on 64-bit systems

2015-03-06T22:40:54+00:00

commit 4e7c22d447bb6d7e37bfe39ff658486ae78e8d77 upstream.

The issue is that the stack for processes is not properly randomized on
64 bit architectures due to an integer overflow.

The affected function is randomize_stack_top() in file
"fs/binfmt_elf.c":

  static unsigned long randomize_stack_top(unsigned long stack_top)
  {
           unsigned int random_variable = 0;

           if ((current->flags & PF_RANDOMIZE) &&
                   !(current->personality & ADDR_NO_RANDOMIZE)) {
                   random_variable = get_random_int() & STACK_RND_MASK;
                   random_variable <<= PAGE_SHIFT;
           }
           return PAGE_ALIGN(stack_top) + random_variable;
           return PAGE_ALIGN(stack_top) - random_variable;
  }

Note that, it declares the "random_variable" variable as "unsigned int".
Since the result of the shifting operation between STACK_RND_MASK (which
is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64):

	  random_variable <<= PAGE_SHIFT;

then the two leftmost bits are dropped when storing the result in the
"random_variable". This variable shall be at least 34 bits long to hold
the (22+12) result.

These two dropped bits have an impact on the entropy of process stack.
Concretely, the total stack entropy is reduced by four: from 2^28 to
2^30 (One fourth of expected entropy).

This patch restores back the entropy by correcting the types involved
in the operations in the functions randomize_stack_top() and
stack_maxrandom_size().

The successful fix can be tested with:

  $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done
  7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0                          [stack]
  7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0                          [stack]
  7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0                          [stack]
  7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0                          [stack]
  ...

Once corrected, the leading bytes should be between 7ffc and 7fff,
rather than always being 7fff.

Signed-off-by: Hector Marco-Gisbert 
Signed-off-by: Ismael Ripoll 
[ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ]
Signed-off-by: Kees Cook 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: Al Viro 
Fixes: CVE-2015-1593
Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net
Signed-off-by: Borislav Petkov 
Signed-off-by: Greg Kroah-Hartman

jffs2: fix handling of corrupted summary length

2015-03-06T22:40:53+00:00

commit 164c24063a3eadee11b46575c5482b2f1417be49 upstream.

sm->offset maybe wrong but magic maybe right, the offset do not have CRC.

Badness at c00c7580 [verbose debug info unavailable]
NIP: c00c7580 LR: c00c718c CTR: 00000014
REGS: df07bb40 TRAP: 0700   Not tainted  (2.6.34.13-WR4.3.0.0_standard)
MSR: 00029000   CR: 22084f84  XER: 00000000
TASK = df84d6e0[908] 'mount' THREAD: df07a000
GPR00: 00000001 df07bbf0 df84d6e0 00000000 00000001 00000000 df07bb58 00000041
GPR08: 00000041 c0638860 00000000 00000010 22084f88 100636c8 df814ff8 00000000
GPR16: df84d6e0 dfa558cc c05adb90 00000048 c0452d30 00000000 000240d0 000040d0
GPR24: 00000014 c05ae734 c05be2e0 00000000 00000001 00000000 00000000 c05ae730
NIP [c00c7580] __alloc_pages_nodemask+0x4d0/0x638
LR [c00c718c] __alloc_pages_nodemask+0xdc/0x638
Call Trace:
[df07bbf0] [c00c718c] __alloc_pages_nodemask+0xdc/0x638 (unreliable)
[df07bc90] [c00c7708] __get_free_pages+0x20/0x48
[df07bca0] [c00f4a40] __kmalloc+0x15c/0x1ec
[df07bcd0] [c01fc880] jffs2_scan_medium+0xa58/0x14d0
[df07bd70] [c01ff38c] jffs2_do_mount_fs+0x1f4/0x6b4
[df07bdb0] [c020144c] jffs2_do_fill_super+0xa8/0x260
[df07bdd0] [c020230c] jffs2_fill_super+0x104/0x184
[df07be00] [c0335814] get_sb_mtd_aux+0x9c/0xec
[df07be20] [c033596c] get_sb_mtd+0x84/0x1e8
[df07be60] [c0201ed0] jffs2_get_sb+0x1c/0x2c
[df07be70] [c0103898] vfs_kern_mount+0x78/0x1e8
[df07bea0] [c0103a58] do_kern_mount+0x40/0x100
[df07bec0] [c011fe90] do_mount+0x240/0x890
[df07bf10] [c0120570] sys_mount+0x90/0xd8
[df07bf40] [c00110d8] ret_from_syscall+0x0/0x4

=== Exception: c01 at 0xff61a34
    LR = 0x100135f0
Instruction dump:
38800005 38600000 48010f41 4bfffe1c 4bfc2d15 4bfffe8c 72e90200 4082fc28
3d20c064 39298860 8809000d 68000001 <0f000000> 2f800000 419efc0c 38000001
mount: mounting /dev/mtdblock3 on /common failed: Input/output error

Signed-off-by: Chen Jie 
Signed-off-by: Andrew Morton 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

NFSv4.1: Fix a kfree() of uninitialised pointers in decode_cb_sequence_args

2015-03-06T22:40:50+00:00

commit d8ba1f971497c19cf80da1ea5391a46a5f9fbd41 upstream.

If the call to decode_rc_list() fails due to a memory allocation error,
then we need to truncate the array size to ensure that we only call
kfree() on those pointer that were allocated.

Reported-by: David Ramos 
Fixes: 4aece6a19cf7f ("nfs41: cb_sequence xdr implementation")
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

nfs: don't call blocking operations while !TASK_RUNNING

2015-03-06T22:40:49+00:00

commit 6ffa30d3f734d4f6b478081dfc09592021028f90 upstream.

Bruce reported seeing this warning pop when mounting using v4.1:

     ------------[ cut here ]------------
     WARNING: CPU: 1 PID: 1121 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()
    do not call blocking ops when !TASK_RUNNING; state=1 set at [] prepare_to_wait+0x2f/0x90
    Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer ppdev joydev snd virtio_console virtio_balloon pcspkr serio_raw parport_pc parport pvpanic floppy soundcore i2c_piix4 virtio_blk virtio_net qxl drm_kms_helper ttm drm virtio_pci virtio_ring ata_generic virtio pata_acpi
    CPU: 1 PID: 1121 Comm: nfsv4.1-svc Not tainted 3.19.0-rc4+ #25
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153950- 04/01/2014
     0000000000000000 000000004e5e3f73 ffff8800b998fb48 ffffffff8186ac78
     0000000000000000 ffff8800b998fba0 ffff8800b998fb88 ffffffff810ac9da
     ffff8800b998fb68 ffffffff81c923e7 00000000000004d9 0000000000000000
    Call Trace:
     [] dump_stack+0x4c/0x65
     [] warn_slowpath_common+0x8a/0xc0
     [] warn_slowpath_fmt+0x55/0x70
     [] ? prepare_to_wait+0x2f/0x90
     [] ? prepare_to_wait+0x2f/0x90
     [] __might_sleep+0xbd/0xd0
     [] kmem_cache_alloc_trace+0x243/0x430
     [] ? groups_alloc+0x3e/0x130
     [] groups_alloc+0x3e/0x130
     [] svcauth_unix_accept+0x16e/0x290 [sunrpc]
     [] svc_authenticate+0xe1/0xf0 [sunrpc]
     [] svc_process_common+0x244/0x6a0 [sunrpc]
     [] bc_svc_process+0x1c4/0x260 [sunrpc]
     [] nfs41_callback_svc+0x128/0x1f0 [nfsv4]
     [] ? wait_woken+0xc0/0xc0
     [] ? nfs4_callback_svc+0x60/0x60 [nfsv4]
     [] kthread+0x11f/0x140
     [] ? local_clock+0x15/0x30
     [] ? kthread_create_on_node+0x250/0x250
     [] ret_from_fork+0x7c/0xb0
     [] ? kthread_create_on_node+0x250/0x250
    ---[ end trace 675220a11e30f4f2 ]---

nfs41_callback_svc does most of its work while in TASK_INTERRUPTIBLE,
which is just wrong. Fix that by finishing the wait immediately if we've
found that the list has something on it.

Also, we don't expect this kthread to accept signals, so we should be
using a TASK_UNINTERRUPTIBLE sleep instead. That however, opens us up
hung task warnings from the watchdog, so have the schedule_timeout
wake up every 60s if there's no callback activity.

Reported-by: "J. Bruce Fields" 
Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

xfs: set superblock buffer type correctly

2015-03-06T22:40:47+00:00

commit 3443a3bca54588f43286b725d8648d33a38c86f1 upstream.

When the superblock is modified in a transaction, the commonly
modified fields are not actually copied to the superblock buffer to
avoid the buffer lock becoming a serialisation point. However, there
are some other operations that modify the superblock fields within
the transaction that don't directly log to the superblock but rely
on the changes to be applied during the transaction commit (to
minimise the buffer lock hold time).

When we do this, we fail to mark the buffer log item as being a
superblock buffer and that can lead to the buffer not being marked
with the corect type in the log and hence causing recovery issues.
Fix it by setting the type correctly, similar to xfs_mod_sb()...

Tested-by: Jan Kara 
Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

xfs: inode unlink does not set AGI buffer type

2015-03-06T22:40:47+00:00

commit f19b872b086711bb4b22c3a0f52f16aa920bcc61 upstream.

This leads to log recovery throwing errors like:

XFS (md0): Mounting V5 Filesystem
XFS (md0): Starting recovery (logdev: internal)
XFS (md0): Unknown buffer type 0!
XFS (md0): _xfs_buf_ioapply: no ops on block 0xaea8802/0x1
ffff8800ffc53800: 58 41 47 49 .....

Which is the AGI buffer magic number.

Ensure that we set the type appropriately in both unlink list
addition and removal.

Tested-by: Jan Kara 
Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

xfs: ensure buffer types are set correctly

2015-03-06T22:40:47+00:00

commit 0d612fb570b71ea2e49554a770cff4c489018b2c upstream.

Jan Kara reported that log recovery was finding buffers with invalid
types in them. This should not happen, and indicates a bug in the
logging of buffers. To catch this, add asserts to the buffer
formatting code to ensure that the buffer type is in range when the
transaction is committed.

We don't set a type on buffers being marked stale - they are not
going to get replayed, the format item exists only for recovery to
be able to prevent replay of the buffer, so the type does not
matter. Hence that needs special casing here.

Reported-by: Jan Kara 
Tested-by: Jan Kara 
Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

ext4: prevent bugon on race between write/fcntl

2015-02-11T06:48:17+00:00

commit a41537e69b4aa43f0fea02498c2595a81267383b upstream.

O_DIRECT flags can be toggeled via fcntl(F_SETFL). But this value checked
twice inside ext4_file_write_iter() and __generic_file_write() which
result in BUG_ON inside ext4_direct_IO.

Let's initialize iocb->private unconditionally.

TESTCASE: xfstest:generic/036  https://patchwork.ozlabs.org/patch/402445/

#TYPICAL STACK TRACE:
kernel BUG at fs/ext4/inode.c:2960!
invalid opcode: 0000 [#1] SMP
Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
CPU: 6 PID: 5505 Comm: aio-dio-fcntl-r Not tainted 3.17.0-rc2-00176-gff5c017 #161
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
task: ffff88080e95a7c0 ti: ffff88080f908000 task.ti: ffff88080f908000
RIP: 0010:[]  [] ext4_direct_IO+0x162/0x3d0
RSP: 0018:ffff88080f90bb58  EFLAGS: 00010246
RAX: 0000000000000400 RBX: ffff88080fdb2a28 RCX: 00000000a802c818
RDX: 0000040000080000 RSI: ffff88080d8aeb80 RDI: 0000000000000001
RBP: ffff88080f90bbc8 R08: 0000000000000000 R09: 0000000000001581
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88080d8aeb80
R13: ffff88080f90bbf8 R14: ffff88080fdb28c8 R15: ffff88080fdb2a28
FS:  00007f23b2055700(0000) GS:ffff880818400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23b2045000 CR3: 000000080cedf000 CR4: 00000000000407e0
Stack:
 ffff88080f90bb98 0000000000000000 7ffffffffffffffe ffff88080fdb2c30
 0000000000000200 0000000000000200 0000000000000001 0000000000000200
 ffff88080f90bbc8 ffff88080fdb2c30 ffff88080f90be08 0000000000000200
Call Trace:
 [] generic_file_direct_write+0xed/0x180
 [] __generic_file_write_iter+0x222/0x370
 [] ext4_file_write_iter+0x34b/0x400
 [] ? aio_run_iocb+0x239/0x410
 [] ? aio_run_iocb+0x239/0x410
 [] ? local_clock+0x25/0x30
 [] ? __lock_acquire+0x274/0x700
 [] ? ext4_unwritten_wait+0xb0/0xb0
 [] aio_run_iocb+0x286/0x410
 [] ? local_clock+0x25/0x30
 [] ? lock_release_holdtime+0x29/0x190
 [] ? lookup_ioctx+0x4b/0xf0
 [] do_io_submit+0x55b/0x740
 [] ? do_io_submit+0x3ca/0x740
 [] SyS_io_submit+0x10/0x20
 [] system_call_fastpath+0x16/0x1b
Code: 01 48 8b 80 f0 01 00 00 48 8b 18 49 8b 45 10 0f 85 f1 01 00 00 48 03 45 c8 48 3b 43 48 0f 8f e3 01 00 00 49 83 7c
24 18 00 75 04 <0f> 0b eb fe f0 ff 83 ec 01 00 00 49 8b 44 24 18 8b 00 85 c0 89
RIP  [] ext4_direct_IO+0x162/0x3d0
 RSP 

Reported-by: Sasha Levin 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Dmitry Monakhov 
[hujianyang: Backported to 3.10
 - Move initialization of iocb->private to ext4_file_write() as we don't
   have ext4_file_write_iter(), which is introduced by commit 9b884164.
 - Adjust context to make 'overwrite' changes apply to ext4_file_dio_write()
   as ext4_file_dio_write() is not move into ext4_file_write()]
Signed-off-by: hujianyang 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix deadlock of segment constructor over I_SYNC flag

2015-02-11T06:48:16+00:00

commit 7ef3ff2fea8bf5e4a21cef47ad87710a3d0fdb52 upstream.

Nilfs2 eventually hangs in a stress test with fsstress program.  This
issue was caused by the following deadlock over I_SYNC flag between
nilfs_segctor_thread() and writeback_sb_inodes():

  nilfs_segctor_thread()
    nilfs_segctor_thread_construct()
      nilfs_segctor_unlock()
        nilfs_dispose_list()
          iput()
            iput_final()
              evict()
                inode_wait_for_writeback()  * wait for I_SYNC flag

  writeback_sb_inodes()
     * set I_SYNC flag on inode->i_state
    __writeback_single_inode()
      do_writepages()
        nilfs_writepages()
          nilfs_construct_dsync_segment()
            nilfs_segctor_sync()
               * wait for completion of segment constructor
    inode_sync_complete()
       * clear I_SYNC flag after __writeback_single_inode() completed

writeback_sb_inodes() calls do_writepages() for dirty inodes after
setting I_SYNC flag on inode->i_state.  do_writepages() in turn calls
nilfs_writepages(), which can run segment constructor and wait for its
completion.  On the other hand, segment constructor calls iput(), which
can call evict() and wait for the I_SYNC flag on
inode_wait_for_writeback().

Since segment constructor doesn't know when I_SYNC will be set, it
cannot know whether iput() will block or not unless inode->i_nlink has a
non-zero count.  We can prevent evict() from being called in iput() by
implementing sop->drop_inode(), but it's not preferable to leave inodes
with i_nlink == 0 for long periods because it even defers file
truncation and inode deallocation.  So, this instead resolves the
deadlock by calling iput() asynchronously with a workqueue for inodes
with i_nlink == 0.

Signed-off-by: Ryusuke Konishi 
Cc: Al Viro 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

pstore/ram: avoid atomic accesses for ioremapped regions

2015-02-06T06:35:40+00:00

commit 0405a5cec3406f19e69da07c8111a6bf1088ac29 upstream.

For persistent RAM outside of main memory, the memory may have limitations
on supported accesses. For internal RAM on highbank platform exclusive
accesses are not supported and will hang the system. So atomic_cmpxchg
cannot be used. This commit uses spinlock protection for buffer size and
start updates on ioremapped regions instead.

Signed-off-by: Rob Herring 
Acked-by: Anton Vorontsov 
Signed-off-by: Tony Luck 
[hkp: Backported to 3.10: adjust context]
Signed-off-by: HuKeping