Fix the security problem in the CIFS filesystem DNS lookup code in which a
malicious redirect could be installed by a random user by simply adding a
result record into one of their keyrings with add_key() and then invoking a
CIFS CFS lookup [CVE-2010-2524].
This is done by creating an internal keyring specifically for the caching of
DNS lookups. To enforce the use of this keyring, the module init routine
creates a set of override credentials with the keyring installed as the thread
keyring and instructs request_key() to only install lookup result keys in that
keyring.
The override is then applied around the call to request_key().
This has some additional benefits when a kernel service uses this module to
request a key:
(1) The result keys are owned by root, not the user that caused the lookup.
(2) The result keys don't pop up in the user's keyrings.
(3) The result keys don't come out of the quota of the user that caused the
lookup.
The keyring can be viewed as root by doing cat /proc/keys:
2a0ca6c3 I----- 1 perm 1f030000 0 0 keyring .dns_resolver: 1/4
It can then be listed with 'keyctl list' by root.
# keyctl list 0x2a0ca6c3
1 key in keyring:
726766307: --alswrv 0 0 dns_resolver: foo.bar.com
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-Tested-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Steve French <smfrench@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This bug appears to be the result of a cut-and-paste mistake from the
NTLMv1 code. The function to generate the MAC key was commented out, but
not the conditional above it. The conditional then ended up causing the
session setup key not to be copied to the buffer unless this was the
first session on the socket, and that made all but the first NTLMv2
session setup fail.
Fix this by removing the conditional and all of the commented clutter
that made it difficult to see.
Cc: Stable <stable@kernel.org>
Reported-by: Gunther Deschner <gdeschne@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
It's currently possible for cifs_open to fail after it has already
called cifs_new_fileinfo. In that situation, the new fileinfo will be
leaked as the caller doesn't call fput. That in turn leads to a busy
inodes after umount problem since the fileinfo holds an extra inode
reference now. Shuffle cifs_open around a bit so that it only calls
cifs_new_fileinfo if it's going to succeed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
...and ensure that we propagate the error back to avoid any surprises.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-and-Tested-by: Jeff Layton <jlayton@redhat.com>
...which takes a ton of unneeded arguments and does a lot more pointer
dereferencing than is really needed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
The current scheme of sticking open files on a list and assuming that
cifs_open will scoop them off of it is broken and leads to "Busy
inodes after umount..." errors at unmount time.
The problem is that there is no guarantee that cifs_open will always
be called after a ->lookup or ->create operation. If there are
permissions or other problems, then it's quite likely that it *won't*
be called.
Fix this by fully instantiating the filp whenever the file is created
and pass that filp back to the VFS. If there is a problem, the VFS
can clean up the references.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
Having cifs_posix_open call cifs_new_fileinfo is problematic and
inconsistent with how "regular" opens work. It's also buggy as
cifs_reopen_file calls this function on a reconnect, which creates a new
struct cifsFileInfo that just gets leaked.
Push it out into the callers. This also allows us to get rid of the
"mnt" arg to cifs_posix_open.
Finally, in the event that a cifsFileInfo isn't or can't be created, we
always want to close the filehandle out on the server as the client
won't have a record of the filehandle and can't actually use it. Make
sure that CIFSSMBClose is called in those cases.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
The standard behavior for drop_inode is to delete the inode when the
last reference to it is put and the nlink count goes to 0. This helps
keep inodes that are still considered "not deleted" in cache as long as
possible even when there aren't dentries attached to them.
When server inode numbers are disabled, it's not possible for cifs_iget
to ever match an existing inode (since inode numbers are generated via
iunique). In this situation, cifs can keep a lot of inodes in cache that
will never be used again.
Implement a drop_inode routine that deletes the inode if server inode
numbers are disabled on the mount. This helps keep the cifs inode
caches down to a more manageable size when server inode numbers are
disabled.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Busy-file renames don't actually work across directories, so we need
to limit this code to renames within the same dir.
This fixes the bug detailed here:
https://bugzilla.redhat.com/show_bug.cgi?id=591938
Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Commit 315e995c63 is causing OOM kills
when stress-testing a CIFS filesystem. The VFS readpages operation takes
a page reference. The older code just handed this reference off to the
page cache, but the new code takes an extra one. The simplest fix is to
put the new reference after add_to_page_cache_lru.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The uniqueid field sent by the server when unix extensions are enabled
is currently used sometimes when it shouldn't be. The readdir codepath
is correct, but most others are not. Fix it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We use this value to find an inode within the hash bucket, so we can't
change this without re-hashing the inode. For now, treat this value
as immutable.
Eventually, we should probably use an inode number change on a path
based operation to indicate that the lookup cache is invalid, but that's
a bit more code to deal with.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The old cifs_revalidate logic always revalidated hardlinked inodes.
This hack allowed CIFS to pass some connectathon tests when server inode
numbers aren't used (basic test7, in particular).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
CIFS has stubs for XFS-style quotas without an actual implementation backing
them, hidden behind a config option not visible in Kconfig. Remove these
stubs for now as the quota operations will see some major changes and this
code simply gets in the way.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When we made serverino the default, we trusted that the field sent by the
server in the "uniqueid" field was actually unique. It turns out that it
isn't reliably so.
Samba, in particular, will just put the st_ino in the uniqueid field when
unix extensions are enabled. When a share spans multiple filesystems, it's
quite possible that there will be collisions. This is a server bug, but
when the inodes in question are a directory (as is often the case) and
there is a collision with the root inode of the mount, the result is a
kernel panic on umount.
Fix this by checking explicitly for directory inodes with the same
uniqueid. If that is the case, then we can assume that using server inode
numbers will be a problem and that they should be disabled.
Fixes Samba bugzilla 7407
Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
..otherwise memory allocation errors go undetected.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The comments make it clear the otherwise subtle behavior of cifs_new_fileinfo().
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
--
fs/cifs/dir.c | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)
Signed-off-by: Steve French <sfrench@us.ibm.com>
..a left over from the commit 3321b791b2.
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...rather than the secType. This allows us to get rid of the MSKerberos
securityEnum. The client just makes a decision at upcall time.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
So that we can reasonably set up the secType based on both the
NegotiateProtocol response and the parsed mount options.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We can use the is_first_ses_reconnect() function to determine this.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
On lease break we were breaking to readonly leases always
even if write requested. Also removed experimental
ifdef around setlease code
Signed-off-by: Steve French <sfrench@us.ibm.com>
This is a typo, if pvolume_info were NULL it would oops.
This function is used in clean up and error handling. The current code
never passes a NULL pvolume_info, but it could pass a NULL *pvolume_info
if the kmalloc() failed.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...since that more accurately describes what that variable holds.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...it's mostly part of cifs_mount. Break it out into a separate
function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Add a local_nls field to the smb_vol struct and keep a pointer to the
local_nls in it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
While creating a file on a server which supports unix extensions
such as Samba, if a file is being created which does not supply
nameidata (i.e. nd is null), cifs client can oops when calling
cifs_posix_open.
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When process does fork() private_data of files with lock list stays the same
for file descriptors of the parent and of the child. While finishing the child closes
files and deletes locks from the list even if unlocking fails. When the child process
finishes the parent doesn't have lock in lock list and can't unlock previously before
fork() locked region after the child process finished.
This patch provides behaviour to save locks in lock list if unlocking fails.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Neaten cERROR and cFYI macros, reduce text space
~2.5K
Convert '__FILE__ ": " fmt' to '"%s: " fmt', __FILE__' to save text space
Surround macros with do {} while
Add parentheses to macros
Make statement expression macro from macro with assign
Remove now unnecessary parentheses from cFYI and cERROR uses
defconfig with CIFS support old
$ size fs/cifs/built-in.o
text data bss dec hex filename
156012 1760 148 157920 268e0 fs/cifs/built-in.o
defconfig with CIFS support old
$ size fs/cifs/built-in.o
text data bss dec hex filename
153508 1760 148 155416 25f18 fs/cifs/built-in.o
allyesconfig old:
$ size fs/cifs/built-in.o
text data bss dec hex filename
309138 3864 74824 387826 5eaf2 fs/cifs/built-in.o
allyesconfig new
$ size fs/cifs/built-in.o
text data bss dec hex filename
305655 3864 74824 384343 5dd57 fs/cifs/built-in.o
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
add_to_page_cache_lru is exported, so it should be used. Benefits over
using a private pagevec: neater code, 128 bytes fewer stack used, percpu
lru ordering is preserved, and finally don't need to flush pagevec
before returning so batching may be shared with other LRU insertions.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
not overwriting file_lock structure after GET_LK
cifs: Fix a kernel BUG with remote OS/2 server (try #3)
[CIFS] initialize nbytes at the beginning of CIFSSMBWrite()
[CIFS] Add mmap for direct, nobrl cifs mount types
If we have preventing lock, cifs should overwrite file_lock structure
with info about preventing lock. If we haven't preventing lock, cifs
should leave it unchanged except for the lock type (change it to F_UNLCK).
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
While chasing a bug report involving a OS/2 server, I noticed the server sets
pSMBr->CountHigh to a incorrect value even in case of normal writes. This
results in 'nbytes' being computed wrongly and triggers a kernel BUG at
mm/filemap.c.
void iov_iter_advance(struct iov_iter *i, size_t bytes)
{
BUG_ON(i->count < bytes); <--- BUG here
Why the server is setting 'CountHigh' is not clear but only does so after
writing 64k bytes. Though this looks like the server bug, the client side
crash may not be acceptable.
The workaround is to mask off high 16 bits if the number of bytes written as
returned by the server is greater than the bytes requested by the client as
suggested by Jeff Layton.
CC: Stable <stable@kernel.org>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
By doing this we always overwrite nbytes value that is being passed on to
CIFSSMBWrite() and need not rely on the callers to initialize. CIFSSMBWrite2 is
doing this already.
CC: Stable <stable@kernel.org>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
without mmap functions in file_ops OpenOffice can't save changes in
existing document. The same situation you can see with gedit. Also, a.out
format of files can't be executed without mmap.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: trivial white space
[CIFS] checkpatch cleanup
cifs: add cifs_revalidate_file
cifs: add a CIFSSMBUnixQFileInfo function
cifs: add a CIFSSMBQFileInfo function
cifs: overhaul cifs_revalidate and rename to cifs_revalidate_dentry
...to allow updating inode attributes on an existing inode by
filehandle. Change mmap and llseek codepaths to use that
instead of cifs_revalidate_dentry since they have a filehandle
readily available.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
