iommu/vt-d: Handle 36bit addressing for x86-32
authorChris Wilson <chris@chris-wilson.co.uk>
Sat, 22 Aug 2020 16:02:09 +0000 (17:02 +0100)
committerJoerg Roedel <jroedel@suse.de>
Fri, 4 Sep 2020 10:14:28 +0000 (12:14 +0200)
commit29aaebbca4abc4cceb38738483051abefafb6950
treecac0bb145e32c1f2e5079ba7817f5151e46767ed
parent2822e582501b65707089b097e773e6fd70774841
iommu/vt-d: Handle 36bit addressing for x86-32

Beware that the address size for x86-32 may exceed unsigned long.

[    0.368971] UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.c:128:14
[    0.369055] shift exponent 36 is too large for 32-bit type 'long unsigned int'

If we don't handle the wide addresses, the pages are mismapped and the
device read/writes go astray, detected as DMAR faults and leading to
device failure. The behaviour changed (from working to broken) in commit
fa954e683178 ("iommu/vt-d: Delegate the dma domain to upper layer"), but
the error looks older.

Fixes: fa954e683178 ("iommu/vt-d: Delegate the dma domain to upper layer")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: James Sewart <jamessewart@arista.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: <stable@vger.kernel.org> # v5.3+
Link: https://lore.kernel.org/r/20200822160209.28512-1-chris@chris-wilson.co.uk
Signed-off-by: Joerg Roedel <jroedel@suse.de>
drivers/iommu/intel/iommu.c