[Patch Part2 V2 01/17] iommu/vt-d: avoid double free of g_iommus on error recovery path
From: Jiang Liu
Date: Wed Feb 19 2014 - 01:07:20 EST
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:[<ffffffff8143eea6>] [<ffffffff8143eea6>] 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] [<ffffffff8143c904>] ? vsnprintf+0x124/0x6f0
[ 6.960323] [<ffffffff8120a1a9>] ? __kmalloc_track_caller+0x169/0x360
[ 6.967716] [<ffffffff81440e1b>] kvasprintf+0x6b/0x80
[ 6.973552] [<ffffffff81432bf1>] kobject_set_name_vargs+0x21/0x70
[ 6.980552] [<ffffffff8143393d>] kobject_init_and_add+0x4d/0x90
[ 6.987364] [<ffffffff812067c9>] ? __kmalloc+0x169/0x370
[ 6.993492] [<ffffffff8102dbbc>] ? cache_add_dev+0x17c/0x4f0
[ 7.000005] [<ffffffff8102ddfa>] cache_add_dev+0x3ba/0x4f0
[ 7.006327] [<ffffffff821a87ca>] ? i8237A_init_ops+0x14/0x14
[ 7.012842] [<ffffffff821a87f8>] cache_sysfs_init+0x2e/0x61
[ 7.019260] [<ffffffff81002162>] do_one_initcall+0xf2/0x220
[ 7.025679] [<ffffffff810a4a29>] ? parse_args+0x2c9/0x450
[ 7.031903] [<ffffffff8219d1b1>] kernel_init_freeable+0x1c9/0x25b
[ 7.038904] [<ffffffff8219c8d2>] ? do_early_param+0x8a/0x8a
[ 7.045322] [<ffffffff8184d5e0>] ? rest_init+0x150/0x150
[ 7.051447] [<ffffffff8184d5ee>] kernel_init+0xe/0x100
[ 7.057380] [<ffffffff8187b87c>] ret_from_fork+0x7c/0xb0
[ 7.063503] [<ffffffff8184d5e0>] ? 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 <f3> a4 c3 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 20 4c 8b 06 4c 8b
[ 7.094960] RIP [<ffffffff8143eea6>] memcpy+0x6/0x110
[ 7.100856] RSP <ffff880455a89cc8>
[ 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 <jiang.liu@xxxxxxxxxxxxxxx>
---
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 a22c86c..52be755 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;
}
--
1.7.10.4
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