From 5dc331852848a38ca00a2817e5b98a1d0561b116 Mon Sep 17 00:00:00 2001 From: Robert Bragg Date: Mon, 4 Feb 2008 22:29:18 -0800 Subject: mm: don't allow ioremapping of ranges larger than vmalloc space When running with a 16M IOREMAP_MAX_ORDER (on armv7) we found that the vmlist search routine in __get_vm_area_node can mistakenly allow a driver to ioremap a range larger than vmalloc space. If at the time of the ioremap all existing vmlist areas sit below the determined alignment then the search routine continues past all entries and exits the for loop - straight into the found: label - without ever testing for integer wrapping or that the requested size fits. We were seeing a driver successfully ioremap 128M of flash even though there was only 120M of vmalloc space. From that point the system was left with the remainder of the first 16M of space to vmalloc/ioremap within. Signed-off-by: Robert Bragg Acked-by: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4efc41a6e2a..0536dde139d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -254,6 +254,10 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long fl if (addr > end - size) goto out; } + if ((size + addr) < addr) + goto out; + if (addr > end - size) + goto out; found: area->next = *p; -- cgit v1.2.3