2.6.30-stable review patch. If anyone has any objections, please let us know. ------------------ From: Sonny Rao commit ce2ae53b750abfaa012ce408e93da131a5b5649b upstream. get_futex_key() can infinitely loop if it is called on a virtual address that is within a huge page but not aligned to the beginning of that page. The call to get_user_pages_fast will return the struct page for a sub-page within the huge page and the check for page->mapping will always fail. The fix is to call compound_head on the page before checking that it's mapped. Signed-off-by: Sonny Rao Acked-by: Thomas Gleixner Cc: anton@samba.org Cc: rajamony@us.ibm.com Cc: speight@us.ibm.com Cc: mstephen@us.ibm.com Cc: grimm@us.ibm.com Cc: mikey@ozlabs.au.ibm.com LKML-Reference: <20090710231313.GA23572@us.ibm.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/futex.c | 1 + 1 file changed, 1 insertion(+) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -241,6 +241,7 @@ again: if (err < 0) return err; + page = compound_head(page); lock_page(page); if (!page->mapping) { unlock_page(page); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/