[PATCH 4.14 108/189] iommu/vt-d: fix shift-out-of-bounds in bug checking

Greg Kroah-Hartman
2018-06-18T08:35:36Z

From: Changbin Du <changbin.du@intel.com>

[ Upstream commit 0dfc0c792d691f8056f38b5c30789f504be0e467 ]

It allows to flush more than 4GB of device TLBs. So the mask should be
64bit wide. UBSAN captured this fault as below.

[ 3.760024] ================================================================================
[ 3.768440] UBSAN: Undefined behaviour in drivers/iommu/dmar.c:1348:3
[ 3.774864] shift exponent 64 is too large for 32-bit type 'int'
[ 3.780853] CPU: 2 PID: 0 Comm: swapper/2 Tainted: G U 4.17.0-rc1+ #89
[ 3.788661] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016
[ 3.796034] Call Trace:
[ 3.798472] <IRQ>
[ 3.800479] dump_stack+0x90/0xfb
[ 3.803787] ubsan_epilogue+0x9/0x40
[ 3.807353] __ubsan_handle_shift_out_of_bounds+0x10e/0x170
[ 3.812916] ? qi_flush_dev_iotlb+0x124/0x180
[ 3.817261] qi_flush_dev_iotlb+0x124/0x180
[ 3.821437] iommu_flush_dev_iotlb+0x94/0xf0
[ 3.825698] iommu_flush_iova+0x10b/0x1c0
[ 3.829699] ? fq_ring_free+0x1d0/0x1d0
[ 3.833527] iova_domain_flush+0x25/0x40
[ 3.837448] fq_flush_timeout+0x55/0x160
[ 3.841368] ? fq_ring_free+0x1d0/0x1d0
[ 3.845200] ? fq_ring_free+0x1d0/0x1d0
[ 3.849034] call_timer_fn+0xbe/0x310
[ 3.852696] ? fq_ring_free+0x1d0/0x1d0
[ 3.856530] run_timer_softirq+0x223/0x6e0
[ 3.860625] ? sched_clock+0x5/0x10
[ 3.864108] ? sched_clock+0x5/0x10
[ 3.867594] __do_softirq+0x1b5/0x6f5
[ 3.871250] irq_exit+0xd4/0x130
[ 3.874470] smp_apic_timer_interrupt+0xb8/0x2f0
[ 3.879075] apic_timer_interrupt+0xf/0x20
[ 3.883159] </IRQ>
[ 3.885255] RIP: 0010:poll_idle+0x60/0xe7
[ 3.889252] RSP: 0018:ffffb1b201943e30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
[ 3.896802] RAX: 0000000080200000 RBX: 000000000000008e RCX: 000000000000001f
[ 3.903918] RDX: 0000000000000000 RSI: 000000002819aa06 RDI: 0000000000000000
[ 3.911031] RBP: ffff9e93c6b33280 R08: 00000010f717d567 R09: 000000000010d205
[ 3.918146] R10: ffffb1b201943df8 R11: 0000000000000001 R12: 00000000e01b169d
[ 3.925260] R13: 0000000000000000 R14: ffffffffb12aa400 R15: 0000000000000000
[ 3.932382] cpuidle_enter_state+0xb4/0x470
[ 3.936558] do_idle+0x222/0x310
[ 3.939779] cpu_startup_entry+0x78/0x90
[ 3.943693] start_secondary+0x205/0x2e0
[ 3.947607] secondary_startup_64+0xa5/0xb0
[ 3.951783] ================================================================================

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iommu/dmar.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1342,7 +1342,7 @@ void qi_flush_dev_iotlb(struct intel_iom
struct qi_desc desc;

if (mask) {
- BUG_ON(addr & ((1 << (VTD_PAGE_SHIFT + mask)) - 1));
+ BUG_ON(addr & ((1ULL << (VTD_PAGE_SHIFT + mask)) - 1));
addr |= (1ULL << (VTD_PAGE_SHIFT + mask - 1)) - 1;
desc.high = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
} else