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| author | Manfred Spraul <manfred@colorfullife.com> | 2008-04-29 10:00:57 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 17:06:14 +0200 |
| commit | 9edff4ab1f8d82675277a04e359d0ed8bf14a7b7 (patch) | |
| tree | 05e67ca13f78b0eff666a4424e03dd6d0fa964c7 /ipc/sem.c | |
| parent | ipc: add definitions of USHORT_MAX and others (diff) | |
| download | linux-9edff4ab1f8d82675277a04e359d0ed8bf14a7b7.tar.xz linux-9edff4ab1f8d82675277a04e359d0ed8bf14a7b7.zip | |
ipc: sysvsem: implement sys_unshare(CLONE_SYSVSEM)
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing
undo lists.
Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM)
The original reason to not support it was the potential (inevitable?)
confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the
inverse meaning of clone(CLONE_SYSVSEM).
Our two most reasonable options then appear to be (1) fully support
CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM,
but always do it anyway on unshare(CLONE_SYSVSEM). This patch does
(1).
Changelog:
Apr 16: SEH: switch to Manfred's alternative patch which
removes the unshare_semundo() function which
always refused CLONE_SYSVSEM.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.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 'ipc/sem.c')
| -rw-r--r-- | ipc/sem.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index d56d3ab6bb8a..e9418df5ff3e 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -1250,6 +1250,7 @@ void exit_sem(struct task_struct *tsk) undo_list = tsk->sysvsem.undo_list; if (!undo_list) return; + tsk->sysvsem.undo_list = NULL; if (!atomic_dec_and_test(&undo_list->refcnt)) return; |