diff options
| author | Takashi Iwai <tiwai@suse.de> | 2018-04-13 15:35:13 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-24 09:34:09 +0200 |
| commit | 0df9b12d7790ccf259c24e8ad92abcfa8da2e0f7 (patch) | |
| tree | 7b53914459565f8e187595b4f445528b1cb35a0e /kernel | |
| parent | 52b329d678e8495bda4d943df6444403f41c57ff (diff) | |
resource: fix integer overflow at reallocation
commit 60bb83b81169820c691fbfa33a6a4aef32aa4b0b upstream.
We've got a bug report indicating a kernel panic at booting on an x86-32
system, and it turned out to be the invalid PCI resource assigned after
reallocation. __find_resource() first aligns the resource start address
and resets the end address with start+size-1 accordingly, then checks
whether it's contained. Here the end address may overflow the integer,
although resource_contains() still returns true because the function
validates only start and end address. So this ends up with returning an
invalid resource (start > end).
There was already an attempt to cover such a problem in the commit
47ea91b4052d ("Resource: fix wrong resource window calculation"), but
this case is an overseen one.
This patch adds the validity check of the newly calculated resource for
avoiding the integer overflow problem.
Bugzilla: http://bugzilla.opensuse.org/show_bug.cgi?id=1086739
Link: http://lkml.kernel.org/r/s5hpo37d5l8.wl-tiwai@suse.de
Fixes: 23c570a67448 ("resource: ability to resize an allocated resource")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reported-by: Michael Henders <hendersm@shaw.ca>
Tested-by: Michael Henders <hendersm@shaw.ca>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/resource.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 9b5f04404152..7ee3dd1ad2af 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -633,7 +633,8 @@ static int __find_resource(struct resource *root, struct resource *old, alloc.start = constraint->alignf(constraint->alignf_data, &avail, size, constraint->align); alloc.end = alloc.start + size - 1; - if (resource_contains(&avail, &alloc)) { + if (alloc.start <= alloc.end && + resource_contains(&avail, &alloc)) { new->start = alloc.start; new->end = alloc.end; return 0; |