From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 3 Nov 2006 14:42:43 +1100 From: Stephen Rothwell Subject: [PATCH] Fix sys_move_pages when a NULL node list is passed. Message-Id: <20061103144243.4601ba76.sfr@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: LKML , linux-mm@kvack.org, stable@kernel.org, Andrew Morton List-ID: sys_move_pages() uses vmalloc() to allocate an array of structures that is fills with information passed from user mode and then passes to do_stat_pages() (in the case the node list is NULL). do_stat_pages() depends on a marker in the node field of the structure to decide how large the array is and this marker is correctly inserted into the last element of the array. However, vmalloc() doesn't zero the memory it allocates and if the user passes NULL for the node list, then the node fields are not filled in (except for the end marker). If the memory the vmalloc() returned happend to have a word with the marker value in it in just the right place, do_pages_stat will fail to fill the status field of part of the array and we will return (random) kernel data to user mode. Signed-off-by: Stephen Rothwell --- mm/migrate.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) This has been tested in PowerPC (after wiring up sys_move_pages). This should go into 2.6.19 as it leaks kernel memory. It should also be submitted to the 2.6.18 stable tree (as sys_move_pages was introduced before 2.6.18-rc2). -- Cheers, Stephen Rothwell sfr@canb.auug.org.au diff --git a/mm/migrate.c b/mm/migrate.c index ba2453f..b4979d4 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -952,7 +952,8 @@ asmlinkage long sys_move_pages(pid_t pid goto out; pm[i].node = node; - } + } else + pm[i].node = 0; /* anything to not match MAX_NUMNODES */ } /* End marker */ pm[nr_pages].node = MAX_NUMNODES; -- 1.4.3.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org