]> git.openfabrics.org - ~shefty/rdma-dev.git/commit
pid-namespace: limit value of ns_last_pid to (0, max_pid)
authorAndrew Vagin <avagin@openvz.org>
Mon, 17 Sep 2012 21:09:12 +0000 (14:09 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 17 Sep 2012 22:00:38 +0000 (15:00 -0700)
commit579035dc5ddd6d48fd8529e7358b03d911ab9d8a
treebd54e0a33715547454b241124258c0c3c0d2be5e
parent35c448a8a3471b95ebc0ebcf91eb1183401b4274
pid-namespace: limit value of ns_last_pid to (0, max_pid)

The kernel doesn't check the pid for negative values, so if you try to
write -2 to /proc/sys/kernel/ns_last_pid, you will get a kernel panic.

The crash happens because the next pid is -1, and alloc_pidmap() will
try to access to a nonexistent pidmap.

  map = &pid_ns->pidmap[pid/BITS_PER_PAGE];

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/pid_namespace.c