Skip to content

L
linux
Switch branch/tag
  1. 08 Oct, 2005 5 commits
    • David Howells's avatar
      [PATCH] Keys: Split key permissions checking into a .c file · 468ed2b0
      David Howells authored 
      The attached patch splits key permissions checking out of key-ui.h and
moves it into a .c file.  It's quite large and called quite a lot, and
it's about to get bigger with the addition of LSM support for keys...

key_any_permission() is also discarded as it's no longer used.
Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      468ed2b0
    • David Howells's avatar
      [PATCH] Keys: Add request-key process documentation · f1a9badc
      David Howells authored 
      The attached patch adds documentation for the process by which request-key
works, including how it permits helper processes to gain access to the
requestor's keyrings.
Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f1a9badc
    • David Howells's avatar
      [PATCH] key: plug request_key_auth memleak · 74fd92c5
      David Howells authored 
      Plug request_key_auth memleak.  This can be triggered by unprivileged
users, so is local DoS.
Signed-off-by: default avatarChris Wright <chrisw@osdl.org>
Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      74fd92c5
    • David Vrabel's avatar
      [PATCH] yenta: fix build if YENTA && !CARDBUS · c2059b2e
      David Vrabel authored 
      (struct pcmcia_socket).tune_bridge only exists if CONFIG_CARDBUS is set
but building yenta_socket without CardBus is valid.
Signed-off-by: default avatarDavid Vrabel <dvrabel@arcom.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c2059b2e
    • Oleg Nesterov's avatar
      [PATCH] fix do_coredump() vs SIGSTOP race · 788e05a6
      Oleg Nesterov authored 
      Let's suppose we have 2 threads in thread group:
	A - does coredump
	B - has pending SIGSTOP

thread A						thread B

do_coredump:						get_signal_to_deliver:

  lock(->sighand)
  ->signal->flags = SIGNAL_GROUP_EXIT
  unlock(->sighand)

							lock(->sighand)
							signr = dequeue_signal()
								->signal->flags |= SIGNAL_STOP_DEQUEUED
								return SIGSTOP;

							do_signal_stop:
							    unlock(->sighand)

  coredump_wait:

      zap_threads:
          lock(tasklist_lock)
          send SIGKILL to B
              // signal_wake_up() does nothing
          unlock(tasklist_lock)

							    lock(tasklist_lock)
							    lock(->sighand)
							    re-check sig->flags & SIGNAL_STOP_DEQUEUED, yes
							    set_current_state(TASK_STOPPED);
							    finish_stop:
							        schedule();
							            // ->state == TASK_STOPPED

      wait_for_completion(&startup_done)
         // waits for complete() from B,
         // ->state == TASK_UNINTERRUPTIBLE

We can't wake up 'B' in any way:

	SIGCONT will be ignored because handle_stop_signal() sees
	->signal->flags & SIGNAL_GROUP_EXIT.

	sys_kill(SIGKILL)->__group_complete_signal() will choose
	uninterruptible 'A', so it can't help.

	sys_tkill(B, SIGKILL) will be ignored by specific_send_sig_info()
	because B already has pending SIGKILL.

This scenario is not possbile if 'A' does do_group_exit(), because
it sets sig->flags = SIGNAL_GROUP_EXIT and delivers SIGKILL to
subthreads atomically, holding both tasklist_lock and sighand->lock.
That means that do_signal_stop() will notice !SIGNAL_STOP_DEQUEUED
after re-locking ->sighand. And it is not possible to any other
thread to re-add SIGNAL_STOP_DEQUEUED later, because dequeue_signal()
can only return SIGKILL.

I think it is better to change do_coredump() to do sigaddset(SIGKILL)
and signal_wake_up() under sighand->lock, but this patch is much
simpler.
Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      788e05a6
  3. 07 Oct, 2005 1 commit
  5. 06 Oct, 2005 7 commits
  7. 05 Oct, 2005 22 commits
  9. 04 Oct, 2005 5 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7