No functional changes.
keyctl_session_to_parent() is the only user of signal->count which needs
the correct value. Change it to use thread_group_empty() instead, this
must be strictly equivalent under tasklist, and imho looks better.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
call_usermodehelper_keys() uses call_usermodehelper_setkeys() to change
subprocess_info->cred in advance. Now that we have info->init() we can
change this code to set tgcred->session_keyring in context of execing
kernel thread.
Note: since currently call_usermodehelper_keys() is never called with
UMH_NO_WAIT, call_usermodehelper_keys()->key_get() and umh_keys_cleanup()
are not really needed, we could rely on install_session_keyring_to_cred()
which does key_get() on success.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
USHORT_MAX/SHORT_MAX/SHORT_MIN.
- Make SHRT_MIN of type s16, not int, for consistency.
[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We were using the wrong variable here so the error codes weren't being returned
properly. The original code returns -ENOKEY.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Do preallocation for __key_link() so that the various callers in request_key.c
can deal with any errors from this source before attempting to construct a key.
This allows them to assume that the actual linkage step is guaranteed to be
successful.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Errors from construct_alloc_key() shouldn't just be ignored in the way they are
by construct_key_and_link(). The only error that can be ignored so is
EINPROGRESS as that is used to indicate that we've found a key and don't need
to construct one.
We don't, however, handle ENOMEM, EDQUOT or EACCES to indicate allocation
failures of one sort or another.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
keyring_serialise_link_sem is only needed for keyring->keyring links as it's
used to prevent cycle detection from being avoided by parallel keyring
additions.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
call_sbin_request_key() creates a keyring and then attempts to insert a link to
the authorisation key into that keyring, but does so without holding a write
lock on the keyring semaphore.
It will normally get away with this because it hasn't told anyone that the
keyring exists yet. The new keyring, however, has had its serial number
published, which means it can be accessed directly by that handle.
This was found by a previous patch that adds RCU lockdep checks to the code
that reads the keyring payload pointer, which includes a check that the keyring
semaphore is actually locked.
Without this patch, the following command:
keyctl request2 user b a @s
will provoke the following lockdep warning is displayed in dmesg:
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
security/keys/keyring.c:727 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
2 locks held by keyctl/2076:
#0: (key_types_sem){.+.+.+}, at: [<ffffffff811a5b29>] key_type_lookup+0x1c/0x71
#1: (keyring_serialise_link_sem){+.+.+.}, at: [<ffffffff811a6d1e>] __key_link+0x4d/0x3c5
stack backtrace:
Pid: 2076, comm: keyctl Not tainted 2.6.34-rc6-cachefs #54
Call Trace:
[<ffffffff81051fdc>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffff811a6d1e>] ? __key_link+0x4d/0x3c5
[<ffffffff811a6e6f>] __key_link+0x19e/0x3c5
[<ffffffff811a5952>] ? __key_instantiate_and_link+0xb1/0xdc
[<ffffffff811a59bf>] ? key_instantiate_and_link+0x42/0x5f
[<ffffffff811aa0dc>] call_sbin_request_key+0xe7/0x33b
[<ffffffff8139376a>] ? mutex_unlock+0x9/0xb
[<ffffffff811a5952>] ? __key_instantiate_and_link+0xb1/0xdc
[<ffffffff811a59bf>] ? key_instantiate_and_link+0x42/0x5f
[<ffffffff811aa6fa>] ? request_key_auth_new+0x1c2/0x23c
[<ffffffff810aaf15>] ? cache_alloc_debugcheck_after+0x108/0x173
[<ffffffff811a9d00>] ? request_key_and_link+0x146/0x300
[<ffffffff810ac568>] ? kmem_cache_alloc+0xe1/0x118
[<ffffffff811a9e45>] request_key_and_link+0x28b/0x300
[<ffffffff811a89ac>] sys_request_key+0xf7/0x14a
[<ffffffff81052c0b>] ? trace_hardirqs_on_caller+0x10c/0x130
[<ffffffff81394fb9>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
The keyring key type code should use RCU dereference wrappers, even when it
holds the keyring's key semaphore.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
key_gc_keyring() needs to either hold the RCU read lock or hold the keyring
semaphore if it's going to scan the keyring's list. Given that it only needs
to read the key list, and it's doing so under a spinlock, the RCU read lock is
the thing to use.
Furthermore, the RCU check added in e7b0a61b79 is
incorrect as holding the spinlock on key_serial_lock is not grounds for
assuming a keyring's pointer list can be read safely. Instead, a simple
rcu_dereference() inside of the previously mentioned RCU read lock is what we
want.
Reported-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
keys: don't need to use RCU in keyring_read() as semaphore is held
The request_key() system call and request_key_and_link() should make a
link from an existing key to the destination keyring (if supplied), not
just from a new key to the destination keyring.
This can be tested by:
ring=`keyctl newring fred @s`
keyctl request2 user debug:a a
keyctl request user debug:a $ring
keyctl list $ring
If it says:
keyring is empty
then it didn't work. If it shows something like:
1 key in keyring:
1070462727: --alswrv 0 0 user: debug:a
then it did.
request_key() system call is meant to recursively search all your keyrings for
the key you desire, and, optionally, if it doesn't exist, call out to userspace
to create one for you.
If request_key() finds or creates a key, it should, optionally, create a link
to that key from the destination keyring specified.
Therefore, if, after a successful call to request_key() with a desination
keyring specified, you see the destination keyring empty, the code didn't work
correctly.
If you see the found key in the keyring, then it did - which is what the patch
is required for.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
keyring_read() doesn't need to use rcu_dereference() to access the keyring
payload as the caller holds the key semaphore to prevent modifications
from happening whilst the data is read out.
This should solve the following warning:
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
security/keys/keyring.c:204 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
1 lock held by keyctl/2144:
#0: (&key->sem){+++++.}, at: [<ffffffff81177f7c>] keyctl_read_key+0x9c/0xcf
stack backtrace:
Pid: 2144, comm: keyctl Not tainted 2.6.34-rc2-cachefs #113
Call Trace:
[<ffffffff8105121f>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffff811762d5>] keyring_read+0x4d/0xe7
[<ffffffff81177f8c>] keyctl_read_key+0xac/0xcf
[<ffffffff811788d4>] sys_keyctl+0x75/0xb9
[<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
Fix the following RCU warning:
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
security/keys/request_key.c:116 invoked rcu_dereference_check() without protection!
This was caused by doing:
[root@andromeda ~]# keyctl newring fred @s
539196288
[root@andromeda ~]# keyctl request2 user a a 539196288
request_key: Required key not available
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
This fixes to include <linux/uaccess.h> instead <asm/uaccess.h> and some
code style issues like to put a else sentence below close brace '}' and
to replace a tab instead of some space characters.
Signed-off-by: Chihau Chau <chihau@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
As of commit ee18d64c1f ("KEYS: Add a keyctl to
install a process's session keyring on its parent [try #6]"), CONFIG_KEYS=y
fails to build on architectures that haven't implemented TIF_NOTIFY_RESUME yet:
security/keys/keyctl.c: In function 'keyctl_session_to_parent':
security/keys/keyctl.c:1312: error: 'TIF_NOTIFY_RESUME' undeclared (first use in this function)
security/keys/keyctl.c:1312: error: (Each undeclared identifier is reported only once
security/keys/keyctl.c:1312: error: for each function it appears in.)
Make KEYCTL_SESSION_TO_PARENT depend on TIF_NOTIFY_RESUME until
m68k, and xtensa have implemented it.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
