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author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2006-02-10 01:51:12 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-10 08:13:12 -0800 |
commit | 8e36709d8cea48a4d341294ce2b46678a2e77159 (patch) | |
tree | bfb3f096c111e2feaab53e386e199d553df36482 /ipc | |
parent | c22db9412736204b25aeba19d18e5ea922f7d632 (diff) | |
download | linux-8e36709d8cea48a4d341294ce2b46678a2e77159.tar.gz |
[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')
-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 4c28d2d8e305..9162123a7b23 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; |