Re: [RFC PATCH] iommu/vt-d: avoid panic in __dmar_remove_one_dev_info
From: Jerry Snitselaar
Date: Tue Dec 17 2019 - 15:50:04 EST
On Tue Dec 17 19, Jerry Snitselaar wrote:
On Tue Dec 17 19, Jerry Snitselaar wrote:
In addition to checking for a null pointer, verify that
info does not have the value DEFER_DEVICE_DOMAIN_INFO or
DUMMY_DEVICE_DOMAIN_INFO. If info has one of those values
__dmar_remove_one_dev_info will panic when trying to access
a member of the device_domain_info struct.
[ 1.464241] BUG: unable to handle kernel NULL pointer dereference at 000000000000004e
[ 1.464241] PGD 0 P4D 0
[ 1.464241] Oops: 0000 [#1] SMP PTI
[ 1.464241] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W --------- - - 4.18.0-160.el8.x86_64 #1
[ 1.464241] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 07/21/2019
[ 1.464241] RIP: 0010:__dmar_remove_one_dev_info+0x27/0x250
[ 1.464241] Code: 00 00 00 0f 1f 44 00 00 8b 05 35 ec 75 01 41 56 41 55 41 54 55 53 85 c0 0f 84 99 01 00 00 48 85 ff 0f 84 92 01 00 00 48 89 fb <4c> 8b 67 50 48 8b 6f 58 $
[ 1.464241] RSP: 0000:ffffc900000dfd10 EFLAGS: 00010082
[ 1.464241] RAX: 0000000000000001 RBX: fffffffffffffffe RCX: 0000000000000000
[ 1.464241] RDX: 0000000000000001 RSI: 0000000000000004 RDI: fffffffffffffffe
[ 1.464241] RBP: ffff88ec7a72f368 R08: 0000000000000457 R09: 0000000000000039
[ 1.464241] R10: 0000000000000000 R11: ffffc900000dfa58 R12: ffff88ec7a0eec20
[ 1.464241] R13: ffff88ec6fd0eab0 R14: ffffffff81eae980 R15: 0000000000000000
[ 1.464241] FS: 0000000000000000(0000) GS:ffff88ec7a600000(0000) knlGS:0000000000000000
[ 1.464241] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.464241] CR2: 000000000000004e CR3: 0000006c7900a001 C 00000000001606b0
[ 1.464241] Call Trace:
[ 1.464241] dmar_remove_one_dev_info.isra.68+0x27/0x40
[ 1.464241] intel_iommu_add_device+0x124/0x180
[ 1.464241] ? iommu_probe_device+0x40/0x40
[ 1.464241] add_iommu_group+0xa/0x20
[ 1.464241] bus_for_each_dev+0x77/0xc0
[ 1.464241] ? down_write+0xe/0x40
[ 1.464241] bus_set_iommu+0x85/0xc0
[ 1.464241] intel_iommu_init+0x4b4/0x777
[ 1.464241] ? e820__memblock_setup+0x63/0x63
[ 1.464241] ? do_early_param+0x91/0x91
[ 1.464241] pci_iommu_init+0x19/0x45
[ 1.464241] do_one_initcall+0x46/0x1c3
[ 1.464241] ? do_early_param+0x91/0x91
[ 1.464241] kernel_init_freeable+0x1af/0x258
[ 1.464241] ? rest_init+0xaa/0xaa
[ 1.464241] kernel_init+0xa/0x107
[ 1.464241] ret_from_fork+0x35/0x40
[ 1.464241] Modules linked in:
[ 1.464241] CR2: 000000000000004e
[ 1.464241] ---[ end trace 0927d2ba8b8032b5 ]---
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.3+
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: ae23bfb68f28 ("iommu/vt-d: Detach domain before using a private one")
Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0c8d81f56a30..e42a09794fa2 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5163,7 +5163,8 @@ static void dmar_remove_one_dev_info(struct device *dev)
spin_lock_irqsave(&device_domain_lock, flags);
info = dev->archdata.iommu;
- if (info)
+ if (info && info != DEFER_DEVICE_DOMAIN_INFO
+ && info != DUMMY_DEVICE_DOMAIN_INFO)
__dmar_remove_one_dev_info(info);
spin_unlock_irqrestore(&device_domain_lock, flags);
}
--
2.24.0
_______________________________________________
iommu mailing list
iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/iommu
Nack this.
Apparently the issue is just being seen with the kdump kernel. I'm
wondering if it is already solved by 6c3a44ed3c55 ("iommu/vt-d: Turn
off translations at shutdown"). Testing a 5.5 build now.
And a minute later I got a response. The 5.5 kernel hits the original
panic when booting into the kdump kernel.
I need to test with this patch on 5.5, but with a test build of our
kernel with this patch the problem just moves to:
[ 3.742317] pci 0000:01:00.0: Using iommu dma mapping
[ 3.744020] pci 0000:01:00.1: Adding to iommu group 86
[ 3.746697] NMI watchdog: Watchdog detected hard LOCKUP on cpu 0Modules linked in:
[ 3.746697] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.0-167.el8.iommu6.x86_64 #1
[ 3.746697] Hardware name: HP ProLiant DL560 Gen9/ProLiant DL560 Gen9, BIOS P85 07/21/2019
[ 3.746697] RIP: 0010:native_queued_spin_lock_slowpath+0x5d/0x1d0
[ 3.746697] Code: 0f ba 2f 08 0f 92 c0 0f b6 c0 c1 e0 08 89 c2 8b 07 30 e4 09 d0 a9 00 01 ff ff 75 47 85 c$
[ 3.746697] RSP: 0000:ffffc900000f3bd8 EFLAGS: 00000002
[ 3.746697] RAX: 0000000000000101 RBX: 0000000000000046 RCX: ffff88887f170000
[ 3.746697] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff82e8a600
[ 3.746697] RBP: ffff88886fd0ec00 R08: 0000000000000004 R09: ffffc900000f3b94
[ 3.746697] R10: 0000000000000001 R11: ffff88887a4e3200 R12: ffff88887cbf6540
[ 3.746697] R13: 0000000000000001 R14: ffff88887a4e3480 R15: 0000000000000001
[ 3.746697] FS: 0000000000000000(0000) GS:ffff88887f600000(0000) knlGS:0000000000000000
[ 3.746697] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3.746697] CR2: 0000000000000000 CR3: 000000087de0a001 CR4: 00000000003606b0
[ 3.746697] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 3.746697] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 3.746697] Call Trace:
[ 3.746697] _raw_spin_lock_irqsave+0x32/0x40
[ 3.746697] dmar_insert_one_dev_info+0xa3/0x4d0
[ 3.746697] ? free_unref_page_commit+0x91/0x100
[ 3.746697] ? device_to_iommu+0x1a3/0x220
[ 3.746697] domain_add_dev_info+0x50/0x90
[ 3.746697] intel_iommu_attach_device+0xb7/0x140
[ 3.746697] find_domain+0x41/0x60
[ 3.746697] dmar_insert_one_dev_info+0xaf/0x4d0
[ 3.746697] ? device_to_iommu+0x1a3/0x220
[ 3.746697] domain_add_dev_info+0x50/0x90
[ 3.746697] intel_iommu_add_device+0x137/0x180
[ 3.746697] ? iommu_probe_device+0x40/0x
[ 3.746697] add_iommu_group+0xa/0x20
[ 3.746697] bus_for_each_dev+0x77/0xc0
[ 3.746697] ? down_write+0xe/0x40
[ 3.746697] bus_set_iommu+0x85/0xc0
[ 3.746697] intel_iommu_init+0x4b4/0x777
[ 3.746697] ? e820__memblock_setup+0x63/0x63
[ 3.746697] ? do_early_param+0x91/0x91
[ 3.746697] pci_iommu_init+0x19/0x45
[ 3.746697] do_one_initcall+0x46/0x1c3
[ 3.746697] ? do_early_param+0x91/0x91
[ 3.746697] kernel_init_freeable+0x1af/0x258
[ 3.746697] ? rest_init+0xaa/0xaa
[ 3.746697] kernel_init+0xa/0x103
[ 3.746697] ret_from_fork+0x35/0x40