aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorSerge E. Hallyn <serue@us.ibm.com>2008-04-29 04:01:00 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 11:06:14 -0400
commit02fdb36ae7f55db7757b623acd27a62d5000d755 (patch)
tree9d96036a7ee174a2828fbb7497a9f365f4f148a1 /kernel
parent6013f67fc1a4c7fa5bcab2d39c1eaa3e260c7ac1 (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.c12
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);