From 989d51fc99e9df4fb47f34bccf162c59aa386e8c Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:21 +0800 Subject: [PATCH] iommu/vt-d: Avoid double free of g_iommus on error recovery path Array 'g_iommus' may be freed twice on error recovery path in function init_dmars() and free_dmar_iommu(), thus cause random system crash as below. [ 6.774301] IOMMU: dmar init failed [ 6.778310] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 6.785615] software IO TLB [mem 0x76bcf000-0x7abcf000] (64MB) mapped at [ffff880076bcf000-ffff88007abcefff] [ 6.796887] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [ 6.804173] Modules linked in: [ 6.807731] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0-rc1+ #108 [ 6.815122] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRIVTIN1.86B.0047.R00.1402050741 02/05/2014 [ 6.836000] task: ffff880455a80000 ti: ffff880455a88000 task.ti: ffff880455a88000 [ 6.844487] RIP: 0010:[] [] memcpy+0x6/0x110 [ 6.853039] RSP: 0000:ffff880455a89cc8 EFLAGS: 00010293 [ 6.859064] RAX: ffff006568636163 RBX: ffff00656863616a RCX: 0000000000000005 [ 6.867134] RDX: 0000000000000005 RSI: ffffffff81cdc439 RDI: ffff006568636163 [ 6.875205] RBP: ffff880455a89d30 R08: 000000000001bc3b R09: 0000000000000000 [ 6.883275] R10: 0000000000000000 R11: ffffffff81cdc43e R12: ffff880455a89da8 [ 6.891338] R13: ffff006568636163 R14: 0000000000000005 R15: ffffffff81cdc439 [ 6.899408] FS: 0000000000000000(0000) GS:ffff88045b800000(0000) knlGS:0000000000000000 [ 6.908575] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.915088] CR2: ffff88047e1ff000 CR3: 0000000001e0e000 CR4: 00000000001407f0 [ 6.923160] Stack: [ 6.925487] ffffffff8143c904 ffff88045b407e00 ffff006568636163 ffff006568636163 [ 6.934113] ffffffff8120a1a9 ffffffff81cdc43e 0000000000000007 0000000000000000 [ 6.942747] ffff880455a89da8 ffff006568636163 0000000000000007 ffffffff81cdc439 [ 6.951382] Call Trace: [ 6.954197] [] ? vsnprintf+0x124/0x6f0 [ 6.960323] [] ? __kmalloc_track_caller+0x169/0x360 [ 6.967716] [] kvasprintf+0x6b/0x80 [ 6.973552] [] kobject_set_name_vargs+0x21/0x70 [ 6.980552] [] kobject_init_and_add+0x4d/0x90 [ 6.987364] [] ? __kmalloc+0x169/0x370 [ 6.993492] [] ? cache_add_dev+0x17c/0x4f0 [ 7.000005] [] cache_add_dev+0x3ba/0x4f0 [ 7.006327] [] ? i8237A_init_ops+0x14/0x14 [ 7.012842] [] cache_sysfs_init+0x2e/0x61 [ 7.019260] [] do_one_initcall+0xf2/0x220 [ 7.025679] [] ? parse_args+0x2c9/0x450 [ 7.031903] [] kernel_init_freeable+0x1c9/0x25b [ 7.038904] [] ? do_early_param+0x8a/0x8a [ 7.045322] [] ? rest_init+0x150/0x150 [ 7.051447] [] kernel_init+0xe/0x100 [ 7.057380] [] ret_from_fork+0x7c/0xb0 [ 7.063503] [] ? rest_init+0x150/0x150 [ 7.069628] Code: 89 e5 53 48 89 fb 75 16 80 7f 3c 00 75 05 e8 d2 f9 ff ff 48 8b 43 58 48 2b 43 50 88 43 4e 5b 5d c3 90 90 90 90 48 89 f8 48 89 d1 a4 c3 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 20 4c 8b 06 4c 8b [ 7.094960] RIP [] memcpy+0x6/0x110 [ 7.100856] RSP [ 7.104864] ---[ end trace b5d3fdc6c6c28083 ]--- [ 7.110142] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 7.110142] [ 7.120540] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a22c86c867faee..52be7555b0df37 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1298,15 +1298,6 @@ static void free_dmar_iommu(struct intel_iommu *iommu) g_iommus[iommu->seq_id] = NULL; - /* if all iommus are freed, free g_iommus */ - for (i = 0; i < g_num_of_iommus; i++) { - if (g_iommus[i]) - break; - } - - if (i == g_num_of_iommus) - kfree(g_iommus); - /* free context mapping */ free_context_table(iommu); } @@ -2461,7 +2452,7 @@ static int __init init_dmars(void) sizeof(struct deferred_flush_tables), GFP_KERNEL); if (!deferred_flush) { ret = -ENOMEM; - goto error; + goto free_g_iommus; } for_each_active_iommu(iommu, drhd) { @@ -2469,7 +2460,7 @@ static int __init init_dmars(void) ret = iommu_init_domains(iommu); if (ret) - goto error; + goto free_iommu; /* * TBD: @@ -2479,7 +2470,7 @@ static int __init init_dmars(void) ret = iommu_alloc_root_entry(iommu); if (ret) { printk(KERN_ERR "IOMMU: allocate root entry failed\n"); - goto error; + goto free_iommu; } if (!ecap_pass_through(iommu->ecap)) hw_pass_through = 0; @@ -2548,7 +2539,7 @@ static int __init init_dmars(void) ret = iommu_prepare_static_identity_mapping(hw_pass_through); if (ret) { printk(KERN_CRIT "Failed to setup IOMMU pass-through\n"); - goto error; + goto free_iommu; } } /* @@ -2606,7 +2597,7 @@ static int __init init_dmars(void) ret = dmar_set_interrupt(iommu); if (ret) - goto error; + goto free_iommu; iommu_set_root_entry(iommu); @@ -2615,17 +2606,20 @@ static int __init init_dmars(void) ret = iommu_enable_translation(iommu); if (ret) - goto error; + goto free_iommu; iommu_disable_protect_mem_regions(iommu); } return 0; -error: + +free_iommu: for_each_active_iommu(iommu, drhd) free_dmar_iommu(iommu); kfree(deferred_flush); +free_g_iommus: kfree(g_iommus); +error: return ret; }