kernel-ark/security/keys
David Howells 9d1ac65a96 KEYS: Fix RCU no-lock warning in keyctl_session_to_parent()
There's an protected access to the parent process's credentials in the middle
of keyctl_session_to_parent().  This results in the following RCU warning:

  ===================================================
  [ INFO: suspicious rcu_dereference_check() usage. ]
  ---------------------------------------------------
  security/keys/keyctl.c:1291 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-session-/2137:
   #0:  (tasklist_lock){.+.+..}, at: [<ffffffff811ae2ec>] keyctl_session_to_parent+0x60/0x236

  stack backtrace:
  Pid: 2137, comm: keyctl-session- Not tainted 2.6.36-rc2-cachefs+ #1
  Call Trace:
   [<ffffffff8105606a>] lockdep_rcu_dereference+0xaa/0xb3
   [<ffffffff811ae379>] keyctl_session_to_parent+0xed/0x236
   [<ffffffff811af77e>] sys_keyctl+0xb4/0xb6
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

The code should take the RCU read lock to make sure the parents credentials
don't go away, even though it's holding a spinlock and has IRQ disabled.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-10 07:30:00 -07:00
..
compat.c
gc.c KEYS: Fix RCU handling in key_gc_keyring() 2010-05-05 11:39:23 +10:00
internal.h Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
key.c KEYS: Do preallocation for __key_link() 2010-05-06 22:25:02 +10:00
keyctl.c KEYS: Fix RCU no-lock warning in keyctl_session_to_parent() 2010-09-10 07:30:00 -07:00
keyring.c kernel-wide: replace USHORT_MAX, SHORT_MAX and SHORT_MIN with USHRT_MAX, SHRT_MAX and SHRT_MIN 2010-05-25 08:07:02 -07:00
Makefile
permission.c security: whitespace coding style fixes 2010-04-23 10:10:23 +10:00
proc.c KEYS: Make /proc/keys check to see if a key is possessed before security check 2010-08-02 15:34:27 +10:00
process_keys.c KEYS: Make /proc/keys check to see if a key is possessed before security check 2010-08-02 15:34:27 +10:00
request_key_auth.c
request_key.c KEYS: request_key() should return -ENOKEY if the constructed key is negative 2010-08-06 09:17:02 -07:00
sysctl.c
user_defined.c KEYS: Fix an RCU warning in the reading of user keys 2010-05-05 11:38:52 +10:00