diff mbox series

[v2] powerpc/iommu: Fix the iommu group reference leak during platform domain attach

Message ID 170793401503.7491.9431631474642074097.stgit@linux.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series [v2] powerpc/iommu: Fix the iommu group reference leak during platform domain attach | expand

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Commit Message

Shivaprasad G Bhat Feb. 14, 2024, 6:09 p.m. UTC 
The function spapr_tce_platform_iommu_attach_dev() is missing to call
iommu_group_put() when the domain is already set. This refcount leak
shows up with BUG_ON() during DLPAR remove operation as,

  KernelBug: Kernel bug in state 'None': kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries
  <snip>
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries
  NIP:  c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000
  REGS: c0000013aed5f840 TRAP: 0700   Tainted: G          I         (6.8.0-rc3-autotest-g99bd3cb0d12e)
  MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 44002402  XER: 20040000
  CFAR: c000000000a0d170 IRQMASK: 0
  GPR00: c0000000000ff4cc c0000013aed5fae0 c000000001512700 c0000013aa362138
  GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000119c8afd0
  GPR08: 0000000000000000 c000001284442b00 0000000000000001 0000000000001003
  GPR12: 0000000300000000 c0000018ffff2f00 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: c0000013aed5fc40 0000000000000002 0000000000000000 c000000002757d90
  GPR28: c0000000000ff440 c000000002757cb8 c00000183799c1a0 c0000013aa362b00
  NIP [c0000000000ff4d4] iommu_reconfig_notifier+0x94/0x200
  LR [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200
  Call Trace:
  [c0000013aed5fae0] [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200 (unreliable)
  [c0000013aed5fb10] [c0000000001a27b0] notifier_call_chain+0xb8/0x19c
  [c0000013aed5fb70] [c0000000001a2a78] blocking_notifier_call_chain+0x64/0x98
  [c0000013aed5fbb0] [c000000000c4a898] of_reconfig_notify+0x44/0xdc
  [c0000013aed5fc20] [c000000000c4add4] of_detach_node+0x78/0xb0
  [c0000013aed5fc70] [c0000000000f96a8] ofdt_write.part.0+0x86c/0xbb8
  [c0000013aed5fce0] [c00000000069b4bc] proc_reg_write+0xf4/0x150
  [c0000013aed5fd10] [c0000000005bfeb4] vfs_write+0xf8/0x488
  [c0000013aed5fdc0] [c0000000005c0570] ksys_write+0x84/0x140
  [c0000013aed5fe10] [c000000000033358] system_call_exception+0x138/0x330
  [c0000013aed5fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
  --- interrupt: 3000 at 0x20000433acb4
  <snip>
  ---[ end trace 0000000000000000 ]---

The patch makes the iommu_group_get() call only when using it there by
avoiding the leak.

Fixes: a8ca9fc9134c ("powerpc/iommu: Do not do platform domain attach atctions after probe")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Closes: https://lore.kernel.org/all/274e0d2b-b5cc-475e-94e6-8427e88e271d@linux.vnet.ibm.com
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
---
Changelog:
v1: https://lore.kernel.org/all/170784021983.6249.10039296655906636112.stgit@linux.ibm.com/
 - Minor refactor to call the iommu_group_get() only if required.
 - Updated the title, description and signature(Closes/Reported-by).

 arch/powerpc/kernel/iommu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Jason Gunthorpe Feb. 14, 2024, 6:10 p.m. UTC | #1 
On Wed, Feb 14, 2024 at 12:09:24PM -0600, Shivaprasad G Bhat wrote:
> The function spapr_tce_platform_iommu_attach_dev() is missing to call
> iommu_group_put() when the domain is already set. This refcount leak
> shows up with BUG_ON() during DLPAR remove operation as,
> 
>   KernelBug: Kernel bug in state 'None': kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100!
>   Oops: Exception in kernel mode, sig: 5 [#1]
>   LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries
>   <snip>
>   Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries
>   NIP:  c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000
>   REGS: c0000013aed5f840 TRAP: 0700   Tainted: G          I         (6.8.0-rc3-autotest-g99bd3cb0d12e)
>   MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 44002402  XER: 20040000
>   CFAR: c000000000a0d170 IRQMASK: 0
>   GPR00: c0000000000ff4cc c0000013aed5fae0 c000000001512700 c0000013aa362138
>   GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000119c8afd0
>   GPR08: 0000000000000000 c000001284442b00 0000000000000001 0000000000001003
>   GPR12: 0000000300000000 c0000018ffff2f00 0000000000000000 0000000000000000
>   GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>   GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>   GPR24: c0000013aed5fc40 0000000000000002 0000000000000000 c000000002757d90
>   GPR28: c0000000000ff440 c000000002757cb8 c00000183799c1a0 c0000013aa362b00
>   NIP [c0000000000ff4d4] iommu_reconfig_notifier+0x94/0x200
>   LR [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200
>   Call Trace:
>   [c0000013aed5fae0] [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200 (unreliable)
>   [c0000013aed5fb10] [c0000000001a27b0] notifier_call_chain+0xb8/0x19c
>   [c0000013aed5fb70] [c0000000001a2a78] blocking_notifier_call_chain+0x64/0x98
>   [c0000013aed5fbb0] [c000000000c4a898] of_reconfig_notify+0x44/0xdc
>   [c0000013aed5fc20] [c000000000c4add4] of_detach_node+0x78/0xb0
>   [c0000013aed5fc70] [c0000000000f96a8] ofdt_write.part.0+0x86c/0xbb8
>   [c0000013aed5fce0] [c00000000069b4bc] proc_reg_write+0xf4/0x150
>   [c0000013aed5fd10] [c0000000005bfeb4] vfs_write+0xf8/0x488
>   [c0000013aed5fdc0] [c0000000005c0570] ksys_write+0x84/0x140
>   [c0000013aed5fe10] [c000000000033358] system_call_exception+0x138/0x330
>   [c0000013aed5fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
>   --- interrupt: 3000 at 0x20000433acb4
>   <snip>
>   ---[ end trace 0000000000000000 ]---
> 
> The patch makes the iommu_group_get() call only when using it there by
> avoiding the leak.
> 
> Fixes: a8ca9fc9134c ("powerpc/iommu: Do not do platform domain attach atctions after probe")
> Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
> Closes: https://lore.kernel.org/all/274e0d2b-b5cc-475e-94e6-8427e88e271d@linux.vnet.ibm.com
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---
> Changelog:
> v1: https://lore.kernel.org/all/170784021983.6249.10039296655906636112.stgit@linux.ibm.com/
>  - Minor refactor to call the iommu_group_get() only if required.
>  - Updated the title, description and signature(Closes/Reported-by).
> 
>  arch/powerpc/kernel/iommu.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Thanks again,
Jason
Michael Ellerman Feb. 15, 2024, 2:31 a.m. UTC | #2 
Shivaprasad G Bhat <sbhat@linux.ibm.com> writes:
> The function spapr_tce_platform_iommu_attach_dev() is missing to call
> iommu_group_put() when the domain is already set. This refcount leak
> shows up with BUG_ON() during DLPAR remove operation as,
>
>   KernelBug: Kernel bug in state 'None': kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100!
>   Oops: Exception in kernel mode, sig: 5 [#1]
>   LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries
>   <snip>
>   Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries
>   NIP:  c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000
>   REGS: c0000013aed5f840 TRAP: 0700   Tainted: G          I         (6.8.0-rc3-autotest-g99bd3cb0d12e)
>   MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 44002402  XER: 20040000
>   CFAR: c000000000a0d170 IRQMASK: 0
>   GPR00: c0000000000ff4cc c0000013aed5fae0 c000000001512700 c0000013aa362138
>   GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000119c8afd0
>   GPR08: 0000000000000000 c000001284442b00 0000000000000001 0000000000001003
>   GPR12: 0000000300000000 c0000018ffff2f00 0000000000000000 0000000000000000
>   GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>   GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>   GPR24: c0000013aed5fc40 0000000000000002 0000000000000000 c000000002757d90
>   GPR28: c0000000000ff440 c000000002757cb8 c00000183799c1a0 c0000013aa362b00
>   NIP [c0000000000ff4d4] iommu_reconfig_notifier+0x94/0x200
>   LR [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200
>   Call Trace:
>   [c0000013aed5fae0] [c0000000000ff4cc] iommu_reconfig_notifier+0x8c/0x200 (unreliable)
>   [c0000013aed5fb10] [c0000000001a27b0] notifier_call_chain+0xb8/0x19c
>   [c0000013aed5fb70] [c0000000001a2a78] blocking_notifier_call_chain+0x64/0x98
>   [c0000013aed5fbb0] [c000000000c4a898] of_reconfig_notify+0x44/0xdc
>   [c0000013aed5fc20] [c000000000c4add4] of_detach_node+0x78/0xb0
>   [c0000013aed5fc70] [c0000000000f96a8] ofdt_write.part.0+0x86c/0xbb8
>   [c0000013aed5fce0] [c00000000069b4bc] proc_reg_write+0xf4/0x150
>   [c0000013aed5fd10] [c0000000005bfeb4] vfs_write+0xf8/0x488
>   [c0000013aed5fdc0] [c0000000005c0570] ksys_write+0x84/0x140
>   [c0000013aed5fe10] [c000000000033358] system_call_exception+0x138/0x330
>   [c0000013aed5fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
>   --- interrupt: 3000 at 0x20000433acb4
>   <snip>
>   ---[ end trace 0000000000000000 ]---
>
> The patch makes the iommu_group_get() call only when using it there by
> avoiding the leak.
>
> Fixes: a8ca9fc9134c ("powerpc/iommu: Do not do platform domain attach atctions after probe")
> Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
> Closes: https://lore.kernel.org/all/274e0d2b-b5cc-475e-94e6-8427e88e271d@linux.vnet.ibm.com
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---
> Changelog:
> v1: https://lore.kernel.org/all/170784021983.6249.10039296655906636112.stgit@linux.ibm.com/
>  - Minor refactor to call the iommu_group_get() only if required.
>  - Updated the title, description and signature(Closes/Reported-by).

Sorry I already applied v1.

If you send this as a patch on top of v1 with a new change log I can
merge it as a cleanup/rework.

cheers
Shivaprasad G Bhat Feb. 15, 2024, 1:57 p.m. UTC | #3 
On 2/15/24 08:01, Michael Ellerman wrote:
> Shivaprasad G Bhat <sbhat@linux.ibm.com> writes:
>> The function spapr_tce_platform_iommu_attach_dev() is missing to call
>> iommu_group_put() when the domain is already set. This refcount leak
>> shows up with BUG_ON() during DLPAR remove operation as,
<snip>
>>    [c0000013aed5fd10] [c0000000005bfeb4] vfs_write+0xf8/0x488
>>    [c0000013aed5fdc0] [c0000000005c0570] ksys_write+0x84/0x140
>>    [c0000013aed5fe10] [c000000000033358] system_call_exception+0x138/0x330
>>    [c0000013aed5fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
>>    --- interrupt: 3000 at 0x20000433acb4
>>    <snip>
>>    ---[ end trace 0000000000000000 ]---
>>
>> The patch makes the iommu_group_get() call only when using it there by
>> avoiding the leak.
>>
>> Fixes: a8ca9fc9134c ("powerpc/iommu: Do not do platform domain attach atctions after probe")
>> Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
>> Closes: https://lore.kernel.org/all/274e0d2b-b5cc-475e-94e6-8427e88e271d@linux.vnet.ibm.com
>> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
>> ---
>> Changelog:
>> v1: https://lore.kernel.org/all/170784021983.6249.10039296655906636112.stgit@linux.ibm.com/
>>   - Minor refactor to call the iommu_group_get() only if required.
>>   - Updated the title, description and signature(Closes/Reported-by).
> Sorry I already applied v1.
>
> If you send this as a patch on top of v1 with a new change log I can
> merge it as a cleanup/rework.

I have posted the cleanup patch at 
https://lore.kernel.org/linux-iommu/170800513841.2411.13524607664262048895.stgit@linux.ibm.com/

Thank you!

Shivaprasad

> cheers
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d71eac3b2887..37fae3bd89c6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1285,13 +1285,14 @@  spapr_tce_platform_iommu_attach_dev(struct iommu_domain *platform_domain,
 				    struct device *dev)
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct iommu_group *grp = iommu_group_get(dev);
 	struct iommu_table_group *table_group;
+	struct iommu_group *grp;

 	/* At first attach the ownership is already set */
 	if (!domain)
 		return 0;

+	grp = iommu_group_get(dev);
 	table_group = iommu_group_get_iommudata(grp);
 	/*
 	 * The domain being set to PLATFORM from earlier