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 <[email protected]>
Signed-off-by: Serge E. Hallyn <[email protected]>
Acked-by: "Eric W. Biederman" <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: Pierre Peiffer <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2 files changed
