lkml.org 
[lkml]   [2018]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] iommu/vt-d: fix shift-out-of-bounds in bug checking
Hello, any reviewer? Thanks!

On Fri, Apr 20, 2018 at 01:29:55PM +0800, changbin.du@intel.com wrote:
> From: Changbin Du <changbin.du@intel.com>
>
> 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>
> ---
> drivers/iommu/dmar.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> index accf5838..e4ae600 100644
> --- a/drivers/iommu/dmar.c
> +++ b/drivers/iommu/dmar.c
> @@ -1345,7 +1345,7 @@ void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 qdep,
> 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
> --
> 2.7.4
>

--
Thanks,
Changbin Du

\
 
 \ /
  Last update: 2018-04-26 11:15    [W:0.078 / U:0.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site