diff options
| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2006-02-09 02:03:17 -0800 |
|---|---|---|
| committer | Chris Wright <chrisw@sous-sol.org> | 2006-03-01 14:36:31 -0800 |
| commit | bde2fcb4fcc69afb0a6ebd1d8c27a83e475480ed (patch) | |
| tree | 5f2719e5d73a2e26a68827e5ce483fc2ae012ad8 | |
| parent | 8bd69ca8a395caf9385b06713f34ef1562ff362c (diff) | |
[PATCH] shmdt cannot detach not-alined shm segment cleanly.
sys_shmdt() can manage shm segments which are covered by multiple vmas. (This
can happen when a user uses mprotect() after shmat().)
This works well if shm is aligned to PAGE_SIZE, but if not, the last
segment cannot be detached. It is because a comparison in sys_shmdt()
(vma->vm_end - addr) < size
addr == return address of shmat()
size == shmsize, argments to shmget()
size should be aligned to PAGE_SIZE before being compared with vma->vm_end,
which is aligned.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
| -rw-r--r-- | ipc/shm.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index 587d836d80d9..c0e7f4df75d9 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -863,6 +863,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr) * could possibly have landed at. Also cast things to loff_t to * prevent overflows and make comparisions vs. equal-width types. */ + size = PAGE_ALIGN(size); while (vma && (loff_t)(vma->vm_end - addr) <= size) { next = vma->vm_next; |