From b5f36d9e614135470da452f820f161c443d3c83c Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 6 Jan 2014 14:18:19 +0800 Subject: [PATCH] iommu/vt-d: fix invalid memory access when freeing DMAR irq In function free_dmar_iommu(), it sets IRQ handler data to NULL before calling free_irq(), which will cause invalid memory access because free_irq() will access IRQ handler data when calling function dmar_msi_mask(). So only set IRQ handler data to NULL after calling free_irq(). Sample stack dump: [ 13.094010] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 [ 13.103215] IP: [] __lock_acquire+0x4d/0x12a0 [ 13.110104] PGD 0 [ 13.112614] Oops: 0000 [#1] SMP [ 13.116585] Modules linked in: [ 13.120260] CPU: 60 PID: 1 Comm: swapper/0 Tainted: G W 3.13.0-rc1-gerry+ #9 [ 13.129367] Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.99.99.x059.091020121352 09/10/2012 [ 13.142555] task: ffff88042dd38010 ti: ffff88042dd32000 task.ti: ffff88042dd32000 [ 13.151179] RIP: 0010:[] [] __lock_acquire+0x4d/0x12a0 [ 13.160867] RSP: 0000:ffff88042dd33b78 EFLAGS: 00010046 [ 13.166969] RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000000 [ 13.175122] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000048 [ 13.183274] RBP: ffff88042dd33bd8 R08: 0000000000000002 R09: 0000000000000001 [ 13.191417] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88042dd38010 [ 13.199571] R13: 0000000000000000 R14: 0000000000000048 R15: 0000000000000000 [ 13.207725] FS: 0000000000000000(0000) GS:ffff88103f200000(0000) knlGS:0000000000000000 [ 13.217014] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 13.223596] CR2: 0000000000000048 CR3: 0000000001a0b000 CR4: 00000000000407e0 [ 13.231747] Stack: [ 13.234160] 0000000000000004 0000000000000046 ffff88042dd33b98 ffffffff810a567d [ 13.243059] ffff88042dd33c08 ffffffff810bb14c ffffffff828995a0 0000000000000046 [ 13.251969] 0000000000000000 0000000000000000 0000000000000002 0000000000000000 [ 13.260862] Call Trace: [ 13.263775] [] ? trace_hardirqs_off+0xd/0x10 [ 13.270571] [] ? vprintk_emit+0x23c/0x570 [ 13.277058] [] lock_acquire+0x93/0x120 [ 13.283269] [] ? dmar_msi_mask+0x47/0x70 [ 13.289677] [] _raw_spin_lock_irqsave+0x49/0x90 [ 13.296748] [] ? dmar_msi_mask+0x47/0x70 [ 13.303153] [] dmar_msi_mask+0x47/0x70 [ 13.309354] [] irq_shutdown+0x53/0x60 [ 13.315467] [] __free_irq+0x26d/0x280 [ 13.321580] [] free_irq+0xf0/0x180 [ 13.327395] [] free_dmar_iommu+0x271/0x2b0 [ 13.333996] [] ? trace_hardirqs_on+0xd/0x10 [ 13.340696] [] free_iommu+0x17/0x50 [ 13.346597] [] init_dmars+0x691/0x77a [ 13.352711] [] intel_iommu_init+0x351/0x438 [ 13.359400] [] ? iommu_setup+0x27d/0x27d [ 13.365806] [] pci_iommu_init+0x28/0x52 [ 13.372114] [] do_one_initcall+0x122/0x180 [ 13.378707] [] ? parse_args+0x1e8/0x320 [ 13.385016] [] kernel_init_freeable+0x1e1/0x26c [ 13.392100] [] ? do_early_param+0x88/0x88 [ 13.398596] [] ? rest_init+0xd0/0xd0 [ 13.404614] [] kernel_init+0xe/0x130 [ 13.410626] [] ret_from_fork+0x7c/0xb0 [ 13.416829] [] ? rest_init+0xd0/0xd0 [ 13.422842] Code: ec 99 00 85 c0 8b 05 53 05 a5 00 41 0f 45 d8 85 c0 0f 84 ff 00 00 00 8b 05 99 f9 7e 01 49 89 fe 41 89 f7 85 c0 0f 84 03 01 00 00 <49> 8b 06 be 01 00 00 00 48 3d c0 0e 01 82 0f 44 de 41 83 ff 01 [ 13.450191] RIP [] __lock_acquire+0x4d/0x12a0 [ 13.458598] RSP [ 13.462671] CR2: 0000000000000048 [ 13.466551] ---[ end trace c5bd26a37c81d760 ]--- Reviewed-by: Yijing Wang Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 3731bf68ddce1c..7a0984d1c8d5d4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1291,9 +1291,9 @@ void free_dmar_iommu(struct intel_iommu *iommu) iommu_disable_translation(iommu); if (iommu->irq) { - irq_set_handler_data(iommu->irq, NULL); /* This will mask the irq */ free_irq(iommu->irq, iommu); + irq_set_handler_data(iommu->irq, NULL); destroy_irq(iommu->irq); }