linux/ipc
Fabian Frederick 9b24fef9f0 sysv, ipc: fix security-layer leaking
Commit 53dad6d3a8 ("ipc: fix race with LSMs") updated ipc_rcu_putref()
to receive rcu freeing function but used generic ipc_rcu_free() instead
of msg_rcu_free() which does security cleaning.

Running LTP msgsnd06 with kmemleak gives the following:

  cat /sys/kernel/debug/kmemleak

  unreferenced object 0xffff88003c0a11f8 (size 8):
    comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
    hex dump (first 8 bytes):
      1b 00 00 00 01 00 00 00                          ........
    backtrace:
      kmemleak_alloc+0x23/0x40
      kmem_cache_alloc_trace+0xe1/0x180
      selinux_msg_queue_alloc_security+0x3f/0xd0
      security_msg_queue_alloc+0x2e/0x40
      newque+0x4e/0x150
      ipcget+0x159/0x1b0
      SyS_msgget+0x39/0x40
      entry_SYSCALL_64_fastpath+0x13/0x8f

Manfred Spraul suggested to fix sem.c as well and Davidlohr Bueso to
only use ipc_rcu_free in case of security allocation failure in newary()

Fixes: 53dad6d3a8 ("ipc: fix race with LSMs")
Link: http://lkml.kernel.org/r/1470083552-22966-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
..
Makefile ipc/msg: increase MSGMNI, remove scaling 2014-12-13 12:42:52 -08:00
compat.c ipc: resolve shadow warnings 2014-10-14 02:18:23 +02:00
compat_mq.c ipc, kernel: use Linux headers 2014-06-06 16:08:14 -07:00
ipc_sysctl.c ipc/msg: increase MSGMNI, remove scaling 2014-12-13 12:42:52 -08:00
mq_sysctl.c ipc: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
mqueue.c vfs: Generalize filesystem nodev handling. 2016-06-23 15:41:57 -05:00
msg.c sysv, ipc: fix security-layer leaking 2016-08-02 17:31:41 -04:00
msgutil.c ipc,msg: drop dst nil validation in copy_msg 2015-11-06 17:50:42 -08:00
namespace.c ipc: Initialize ipc_namespace->user_ns early. 2016-06-23 15:41:53 -05:00
sem.c sysv, ipc: fix security-layer leaking 2016-08-02 17:31:41 -04:00
shm.c shmem: make shmem_inode_info::lock irq-safe 2016-07-26 16:19:19 -07:00
syscall.c get rid of union semop in sys_semctl(2) arguments 2013-03-05 15:14:16 -05:00
util.c tree wide: use kvfree() than conditional kfree()/vfree() 2016-01-22 17:02:18 -08:00
util.h tree wide: use kvfree() than conditional kfree()/vfree() 2016-01-22 17:02:18 -08:00