linux-stable.git/fs/ecryptfs, branch v3.14.78

ecryptfs: don't allow mmap when the lower fs doesn't support it

2016-08-10T08:21:03+00:00

commit f0fe970df3838c202ef6c07a4c2b36838ef0a88b upstream.

There are legitimate reasons to disallow mmap on certain files, notably
in sysfs or procfs.  We shouldn't emulate mmap support on file systems
that don't offer support natively.

CVE-2016-1583

Signed-off-by: Jeff Mahoney 
[tyhicks: clean up f_op check by using ecryptfs_file_to_lower()]
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

Revert "ecryptfs: forbid opening files without mmap handler"

2016-08-10T08:21:03+00:00

commit 78c4e172412de5d0456dc00d2b34050aa0b683b5 upstream.

This reverts commit 2f36db71009304b3f0b95afacd8eba1f9f046b87.

It fixed a local root exploit but also introduced a dependency on
the lower file system implementing an mmap operation just to open a file,
which is a bit of a heavy hammer.  The right fix is to have mmap depend
on the existence of the mmap handler instead.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

ecryptfs: forbid opening files without mmap handler

2016-06-24T17:15:29+00:00

commit 2f36db71009304b3f0b95afacd8eba1f9f046b87 upstream.

This prevents users from triggering a stack overflow through a recursive
invocation of pagefault handling that involves mapping procfs files into
virtual memory.

Signed-off-by: Jann Horn 
Acked-by: Tyler Hicks 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

eCryptfs: Remove buggy and unnecessary write in file name decode routine

2015-01-08T18:00:51+00:00

commit 942080643bce061c3dd9d5718d3b745dcb39a8bc upstream.

Dmitry Chernenkov used KASAN to discover that eCryptfs writes past the
end of the allocated buffer during encrypted filename decoding. This
fix corrects the issue by getting rid of the unnecessary 0 write when
the current bit offset is 2.

Signed-off-by: Michael Halcrow 
Reported-by: Dmitry Chernenkov 
Suggested-by: Kees Cook 
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

eCryptfs: Force RO mount when encrypted view is enabled

2015-01-08T18:00:50+00:00

commit 332b122d39c9cbff8b799007a825d94b2e7c12f2 upstream.

The ecryptfs_encrypted_view mount option greatly changes the
functionality of an eCryptfs mount. Instead of encrypting and decrypting
lower files, it provides a unified view of the encrypted files in the
lower filesystem. The presence of the ecryptfs_encrypted_view mount
option is intended to force a read-only mount and modifying files is not
supported when the feature is in use. See the following commit for more
information:

  e77a56d [PATCH] eCryptfs: Encrypted passthrough

This patch forces the mount to be read-only when the
ecryptfs_encrypted_view mount option is specified by setting the
MS_RDONLY flag on the superblock. Additionally, this patch removes some
broken logic in ecryptfs_open() that attempted to prevent modifications
of files when the encrypted view feature was in use. The check in
ecryptfs_open() was not sufficient to prevent file modifications using
system calls that do not operate on a file descriptor.

Signed-off-by: Tyler Hicks 
Reported-by: Priya Bansal 
Signed-off-by: Greg Kroah-Hartman

ecryptfs: avoid to access NULL pointer when write metadata in xattr

2014-10-30T16:38:25+00:00

commit 35425ea2492175fd39f6116481fe98b2b3ddd4ca upstream.

Christopher Head 2014-06-28 05:26:20 UTC described:
"I tried to reproduce this on 3.12.21. Instead, when I do "echo hello > foo"
in an ecryptfs mount with ecryptfs_xattr specified, I get a kernel crash:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [] fsstack_copy_attr_all+0x2/0x61
PGD d7840067 PUD b2c3c067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: nvidia(PO)
CPU: 3 PID: 3566 Comm: bash Tainted: P           O 3.12.21-gentoo-r1 #2
Hardware name: ASUSTek Computer Inc. G60JX/G60JX, BIOS 206 03/15/2010
task: ffff8801948944c0 ti: ffff8800bad70000 task.ti: ffff8800bad70000
RIP: 0010:[]  [] fsstack_copy_attr_all+0x2/0x61
RSP: 0018:ffff8800bad71c10  EFLAGS: 00010246
RAX: 00000000000181a4 RBX: ffff880198648480 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffff880172010450 RDI: 0000000000000000
RBP: ffff880198490e40 R08: 0000000000000000 R09: 0000000000000000
R10: ffff880172010450 R11: ffffea0002c51e80 R12: 0000000000002000
R13: 000000000000001a R14: 0000000000000000 R15: ffff880198490e40
FS:  00007ff224caa700(0000) GS:ffff88019fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000bb07f000 CR4: 00000000000007e0
Stack:
ffffffff811826e8 ffff8800a39d8000 0000000000000000 000000000000001a
ffff8800a01d0000 ffff8800a39d8000 ffffffff81185fd5 ffffffff81082c2c
00000001a39d8000 53d0abbc98490e40 0000000000000037 ffff8800a39d8220
Call Trace:
[] ? ecryptfs_setxattr+0x40/0x52
[] ? ecryptfs_write_metadata+0x1b3/0x223
[] ? should_resched+0x5/0x23
[] ? ecryptfs_initialize_file+0xaf/0xd4
[] ? ecryptfs_create+0xf4/0x142
[] ? vfs_create+0x48/0x71
[] ? do_last.isra.68+0x559/0x952
[] ? link_path_walk+0xbd/0x458
[] ? path_openat+0x224/0x472
[] ? do_filp_open+0x2b/0x6f
[] ? __alloc_fd+0xd6/0xe7
[] ? do_sys_open+0x65/0xe9
[] ? system_call_fastpath+0x16/0x1b
RIP  [] fsstack_copy_attr_all+0x2/0x61
RSP 
CR2: 0000000000000000
---[ end trace df9dba5f1ddb8565 ]---"

If we create a file when we mount with ecryptfs_xattr_metadata option, we will
encounter a crash in this path:
->ecryptfs_create
  ->ecryptfs_initialize_file
    ->ecryptfs_write_metadata
      ->ecryptfs_write_metadata_to_xattr
        ->ecryptfs_setxattr
          ->fsstack_copy_attr_all
It's because our dentry->d_inode used in fsstack_copy_attr_all is NULL, and it
will be initialized when ecryptfs_initialize_file finish.

So we should skip copying attr from lower inode when the value of ->d_inode is
invalid.

Signed-off-by: Chao Yu 
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

ecryptfs: fix failure handling in ->readlink()

2014-01-25T08:13:00+00:00

If ecryptfs_readlink_lower() fails, buf remains an uninitialized
pointer and passing it nd_set_link() won't do anything good.

Fixed by switching ecryptfs_readlink_lower() to saner API - make it
return buf or ERR_PTR(...) and update callers.

Signed-off-by: Al Viro

Merge tag 'ecryptfs-3.13-rc1-quiet-checkers' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

2013-11-22T18:58:14+00:00

Pull minor eCryptfs fix from Tyler Hicks:
 "Quiet static checkers by removing unneeded conditionals"

* tag 'ecryptfs-3.13-rc1-quiet-checkers' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: file->private_data is always valid

tree-wide: use reinit_completion instead of INIT_COMPLETION

2013-11-15T00:32:21+00:00

Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.

[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang 
Acked-by: Linus Walleij  (personally at LCE13)
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

eCryptfs: file->private_data is always valid

2013-11-14T20:12:15+00:00

When accessing the lower_file pointer located in private_data of
eCryptfs files, there is no need to check to see if the private_data
pointer has been initialized to a non-NULL value. The file->private_data
and file->private_data->lower_file pointers are always initialized to
non-NULL values in ecryptfs_open().

This change quiets a Smatch warning:

  CHECK   /var/scm/kernel/linux/fs/ecryptfs/file.c
fs/ecryptfs/file.c:321 ecryptfs_unlocked_ioctl() error: potential NULL dereference 'lower_file'.
fs/ecryptfs/file.c:335 ecryptfs_compat_ioctl() error: potential NULL dereference 'lower_file'.

Signed-off-by: Tyler Hicks 
Reported-by: Dan Carpenter 
Reviewed-by: Geyslan G. Bem 
Cc: Al Viro