diff options
author | Takashi Iwai <tiwai@suse.de> | 2018-04-13 18:35:13 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-13 20:10:27 -0400 |
commit | 60bb83b81169820c691fbfa33a6a4aef32aa4b0b (patch) | |
tree | ff4b9f1c7594cc18c6678d9509907b3743131b4c | |
parent | 16e205cf42da1f497b10a4a24f563e6c0d574eec (diff) |
resource: fix integer overflow at reallocation
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>
-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 e270b5048988..2af6c03858b9 100644 --- a/kernel/resource.c +++ b/kernel/resource.c | |||
@@ -651,7 +651,8 @@ static int __find_resource(struct resource *root, struct resource *old, | |||
651 | alloc.start = constraint->alignf(constraint->alignf_data, &avail, | 651 | alloc.start = constraint->alignf(constraint->alignf_data, &avail, |
652 | size, constraint->align); | 652 | size, constraint->align); |
653 | alloc.end = alloc.start + size - 1; | 653 | alloc.end = alloc.start + size - 1; |
654 | if (resource_contains(&avail, &alloc)) { | 654 | if (alloc.start <= alloc.end && |
655 | resource_contains(&avail, &alloc)) { | ||
655 | new->start = alloc.start; | 656 | new->start = alloc.start; |
656 | new->end = alloc.end; | 657 | new->end = alloc.end; |
657 | return 0; | 658 | return 0; |