path: root/ipc
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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2006-02-10 01:51:12 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-10 08:13:12 -0800
commit8e36709d8cea48a4d341294ce2b46678a2e77159 (patch)
treebfb3f096c111e2feaab53e386e199d553df36482 /ipc
parentc22db9412736204b25aeba19d18e5ea922f7d632 (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> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'ipc')
1 files changed, 1 insertions, 0 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 4c28d2d8e30..9162123a7b2 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -870,6 +870,7 @@ 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;