diff options
author | Serge E. Hallyn <serue@us.ibm.com> | 2008-04-29 04:01:00 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 11:06:14 -0400 |
commit | 02fdb36ae7f55db7757b623acd27a62d5000d755 (patch) | |
tree | 9d96036a7ee174a2828fbb7497a9f365f4f148a1 /kernel | |
parent | 6013f67fc1a4c7fa5bcab2d39c1eaa3e260c7ac1 (diff) |
ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC)
CLONE_NEWIPC|CLONE_SYSVSEM interaction isn't handled properly. This can cause
a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo
lists.
Fix, part 3: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC).
With unshare, specifying CLONE_SYSVSEM means unshare the sysvsem. So it seems
reasonable that CLONE_NEWIPC without CLONE_SYSVSEM would just imply
CLONE_SYSVSEM.
However with clone, specifying CLONE_SYSVSEM means *share* the sysvsem. So
calling clone(CLONE_SYSVSEM|CLONE_NEWIPC) is explicitly asking for something
we can't allow. So return -EINVAL in that case.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/nsproxy.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index f5d332cf8c63..adc785146a1c 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c | |||
@@ -139,6 +139,18 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) | |||
139 | goto out; | 139 | goto out; |
140 | } | 140 | } |
141 | 141 | ||
142 | /* | ||
143 | * CLONE_NEWIPC must detach from the undolist: after switching | ||
144 | * to a new ipc namespace, the semaphore arrays from the old | ||
145 | * namespace are unreachable. In clone parlance, CLONE_SYSVSEM | ||
146 | * means share undolist with parent, so we must forbid using | ||
147 | * it along with CLONE_NEWIPC. | ||
148 | */ | ||
149 | if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) { | ||
150 | err = -EINVAL; | ||
151 | goto out; | ||
152 | } | ||
153 | |||
142 | new_ns = create_new_namespaces(flags, tsk, tsk->fs); | 154 | new_ns = create_new_namespaces(flags, tsk, tsk->fs); |
143 | if (IS_ERR(new_ns)) { | 155 | if (IS_ERR(new_ns)) { |
144 | err = PTR_ERR(new_ns); | 156 | err = PTR_ERR(new_ns); |