1. 01 9月, 2010 1 次提交
    • P
      pid: make setpgid() system call use RCU read-side critical section · 950eaaca
      Paul E. McKenney 提交于
      [   23.584719]
      [   23.584720] ===================================================
      [   23.585059] [ INFO: suspicious rcu_dereference_check() usage. ]
      [   23.585176] ---------------------------------------------------
      [   23.585176] kernel/pid.c:419 invoked rcu_dereference_check() without protection!
      [   23.585176]
      [   23.585176] other info that might help us debug this:
      [   23.585176]
      [   23.585176]
      [   23.585176] rcu_scheduler_active = 1, debug_locks = 1
      [   23.585176] 1 lock held by rc.sysinit/728:
      [   23.585176]  #0:  (tasklist_lock){.+.+..}, at: [<ffffffff8104771f>] sys_setpgid+0x5f/0x193
      [   23.585176]
      [   23.585176] stack backtrace:
      [   23.585176] Pid: 728, comm: rc.sysinit Not tainted 2.6.36-rc2 #2
      [   23.585176] Call Trace:
      [   23.585176]  [<ffffffff8105b436>] lockdep_rcu_dereference+0x99/0xa2
      [   23.585176]  [<ffffffff8104c324>] find_task_by_pid_ns+0x50/0x6a
      [   23.585176]  [<ffffffff8104c35b>] find_task_by_vpid+0x1d/0x1f
      [   23.585176]  [<ffffffff81047727>] sys_setpgid+0x67/0x193
      [   23.585176]  [<ffffffff810029eb>] system_call_fastpath+0x16/0x1b
      [   24.959669] type=1400 audit(1282938522.956:4): avc:  denied  { module_request } for  pid=766 comm="hwclock" kmod="char-major-10-135" scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclas
      
      It turns out that the setpgid() system call fails to enter an RCU
      read-side critical section before doing a PID-to-task_struct translation.
      This commit therefore does rcu_read_lock() before the translation, and
      also does rcu_read_unlock() after the last use of the returned pointer.
      Reported-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Acked-by: NDavid Howells <dhowells@redhat.com>
      950eaaca
  2. 26 8月, 2010 2 次提交
  3. 25 8月, 2010 20 次提交
  4. 24 8月, 2010 17 次提交