[PATCH v2] cxl: Avoid double free_irq() for psl,slice interrupts

Subsystems: char and misc drivers, the rest

STALE3349d

5 messages, 5 authors, 2017-06-08 · open the first message on its own page

[PATCH v2] cxl: Avoid double free_irq() for psl,slice interrupts

From: Vaibhav Jain <hidden>
Date: 2017-06-02 16:58:11

During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
  free_irq+0x88/0xd0 (unreliable)
  cxl_unmap_irq+0x20/0x40 [cxl]
  cxl_native_release_psl_irq+0x78/0xd8 [cxl]
  pci_deconfigure_afu+0xac/0x110 [cxl]
  cxl_remove+0x104/0x210 [cxl]
  pci_device_remove+0x6c/0x110
  device_release_driver_internal+0x204/0x2e0
  pci_stop_bus_device+0xa0/0xd0
  pci_stop_and_remove_bus_device+0x28/0x40
  pci_hp_remove_devices+0xb0/0x150
  pci_hp_remove_devices+0x68/0x150
  eeh_handle_normal_event+0x140/0x580
  eeh_handle_event+0x174/0x360
  eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <redacted>

---
Changelog:

v2:
- Use psl_hwirq instead of psl_virq to find irq mapping in
cxl_native_release_psl_irq as pointed out by Fred.

Re-send:
- Added stable to recipients
---
 drivers/misc/cxl/native.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index 871a2f0..8d6ea97 100644
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c

@@ -1302,13 +1302,16 @@ int cxl_native_register_psl_err_irq(struct cxl *adapter)
 
 void cxl_native_release_psl_err_irq(struct cxl *adapter)
 {
-	if (adapter->native->err_virq != irq_find_mapping(NULL, adapter->native->err_hwirq))
+	if (adapter->native->err_virq == 0 ||
+	    adapter->native->err_virq !=
+	    irq_find_mapping(NULL, adapter->native->err_hwirq))
 		return;
 
 	cxl_p1_write(adapter, CXL_PSL_ErrIVTE, 0x0000000000000000);
 	cxl_unmap_irq(adapter->native->err_virq, adapter);
 	cxl_ops->release_one_irq(adapter, adapter->native->err_hwirq);
 	kfree(adapter->irq_name);
+	adapter->native->err_virq = 0;
 }
 
 int cxl_native_register_serr_irq(struct cxl_afu *afu)

@@ -1346,13 +1349,15 @@ int cxl_native_register_serr_irq(struct cxl_afu *afu)
 
 void cxl_native_release_serr_irq(struct cxl_afu *afu)
 {
-	if (afu->serr_virq != irq_find_mapping(NULL, afu->serr_hwirq))
+	if (afu->serr_virq == 0 ||
+	    afu->serr_virq != irq_find_mapping(NULL, afu->serr_hwirq))
 		return;
 
 	cxl_p1n_write(afu, CXL_PSL_SERR_An, 0x0000000000000000);
 	cxl_unmap_irq(afu->serr_virq, afu);
 	cxl_ops->release_one_irq(afu->adapter, afu->serr_hwirq);
 	kfree(afu->err_irq_name);
+	afu->serr_virq = 0;
 }
 
 int cxl_native_register_psl_irq(struct cxl_afu *afu)

@@ -1375,12 +1380,15 @@ int cxl_native_register_psl_irq(struct cxl_afu *afu)
 
 void cxl_native_release_psl_irq(struct cxl_afu *afu)
 {
-	if (afu->native->psl_virq != irq_find_mapping(NULL, afu->native->psl_hwirq))
+	if (afu->native->psl_virq == 0 ||
+	    afu->native->psl_virq !=
+	    irq_find_mapping(NULL, afu->native->psl_hwirq))
 		return;
 
 	cxl_unmap_irq(afu->native->psl_virq, afu);
 	cxl_ops->release_one_irq(afu->adapter, afu->native->psl_hwirq);
 	kfree(afu->psl_irq_name);
+	afu->native->psl_virq = 0;
 }
 
 static void recover_psl_err(struct cxl_afu *afu, u64 errstat)

-- 
2.9.4

Re: [PATCH v2] cxl: Avoid double free_irq() for psl,slice interrupts

From: Andrew Donnellan <hidden>
Date: 2017-06-05 01:53:46

On 03/06/17 02:56, Vaibhav Jain wrote:

During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
  free_irq+0x88/0xd0 (unreliable)
  cxl_unmap_irq+0x20/0x40 [cxl]
  cxl_native_release_psl_irq+0x78/0xd8 [cxl]
  pci_deconfigure_afu+0xac/0x110 [cxl]
  cxl_remove+0x104/0x210 [cxl]
  pci_device_remove+0x6c/0x110
  device_release_driver_internal+0x204/0x2e0
  pci_stop_bus_device+0xa0/0xd0
  pci_stop_and_remove_bus_device+0x28/0x40
  pci_hp_remove_devices+0xb0/0x150
  pci_hp_remove_devices+0x68/0x150
  eeh_handle_normal_event+0x140/0x580
  eeh_handle_event+0x174/0x360
  eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <redacted>

v2 change looks good to me

Reviewed-by: Andrew Donnellan <redacted>

-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com  IBM Australia Limited

Re: [PATCH v2] cxl: Avoid double free_irq() for psl,slice interrupts

From: Frederic Barrat <hidden>
Date: 2017-06-06 08:10:04


Le 02/06/2017 à 18:56, Vaibhav Jain a écrit :

During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
   free_irq+0x88/0xd0 (unreliable)
   cxl_unmap_irq+0x20/0x40 [cxl]
   cxl_native_release_psl_irq+0x78/0xd8 [cxl]
   pci_deconfigure_afu+0xac/0x110 [cxl]
   cxl_remove+0x104/0x210 [cxl]
   pci_device_remove+0x6c/0x110
   device_release_driver_internal+0x204/0x2e0
   pci_stop_bus_device+0xa0/0xd0
   pci_stop_and_remove_bus_device+0x28/0x40
   pci_hp_remove_devices+0xb0/0x150
   pci_hp_remove_devices+0x68/0x150
   eeh_handle_normal_event+0x140/0x580
   eeh_handle_event+0x174/0x360
   eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <redacted>

---

Thanks for the correction.

Acked-by: Frederic Barrat <redacted>

   Fred

quoted hunk

Changelog:

v2:
- Use psl_hwirq instead of psl_virq to find irq mapping in
cxl_native_release_psl_irq as pointed out by Fred.

Re-send:
- Added stable to recipients
---
  drivers/misc/cxl/native.c | 14 +++++++++++---
  1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index 871a2f0..8d6ea97 100644
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c

@@ -1302,13 +1302,16 @@ int cxl_native_register_psl_err_irq(struct cxl *adapter)

  void cxl_native_release_psl_err_irq(struct cxl *adapter)
  {
-	if (adapter->native->err_virq != irq_find_mapping(NULL, adapter->native->err_hwirq))
+	if (adapter->native->err_virq == 0 ||
+	    adapter->native->err_virq !=
+	    irq_find_mapping(NULL, adapter->native->err_hwirq))
  		return;

  	cxl_p1_write(adapter, CXL_PSL_ErrIVTE, 0x0000000000000000);
  	cxl_unmap_irq(adapter->native->err_virq, adapter);
  	cxl_ops->release_one_irq(adapter, adapter->native->err_hwirq);
  	kfree(adapter->irq_name);
+	adapter->native->err_virq = 0;
  }

  int cxl_native_register_serr_irq(struct cxl_afu *afu)

@@ -1346,13 +1349,15 @@ int cxl_native_register_serr_irq(struct cxl_afu *afu)

  void cxl_native_release_serr_irq(struct cxl_afu *afu)
  {
-	if (afu->serr_virq != irq_find_mapping(NULL, afu->serr_hwirq))
+	if (afu->serr_virq == 0 ||
+	    afu->serr_virq != irq_find_mapping(NULL, afu->serr_hwirq))
  		return;

  	cxl_p1n_write(afu, CXL_PSL_SERR_An, 0x0000000000000000);
  	cxl_unmap_irq(afu->serr_virq, afu);
  	cxl_ops->release_one_irq(afu->adapter, afu->serr_hwirq);
  	kfree(afu->err_irq_name);
+	afu->serr_virq = 0;
  }

  int cxl_native_register_psl_irq(struct cxl_afu *afu)

@@ -1375,12 +1380,15 @@ int cxl_native_register_psl_irq(struct cxl_afu *afu)

  void cxl_native_release_psl_irq(struct cxl_afu *afu)
  {
-	if (afu->native->psl_virq != irq_find_mapping(NULL, afu->native->psl_hwirq))
+	if (afu->native->psl_virq == 0 ||
+	    afu->native->psl_virq !=
+	    irq_find_mapping(NULL, afu->native->psl_hwirq))
  		return;

  	cxl_unmap_irq(afu->native->psl_virq, afu);
  	cxl_ops->release_one_irq(afu->adapter, afu->native->psl_hwirq);
  	kfree(afu->psl_irq_name);
+	afu->native->psl_virq = 0;
  }

  static void recover_psl_err(struct cxl_afu *afu, u64 errstat)

Re: [PATCH v2] cxl: Avoid double free_irq() for psl,slice interrupts

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2017-06-06 09:17:30

Vaibhav Jain [off-list ref] writes:

During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
  free_irq+0x88/0xd0 (unreliable)
  cxl_unmap_irq+0x20/0x40 [cxl]
  cxl_native_release_psl_irq+0x78/0xd8 [cxl]
  pci_deconfigure_afu+0xac/0x110 [cxl]
  cxl_remove+0x104/0x210 [cxl]
  pci_device_remove+0x6c/0x110
  device_release_driver_internal+0x204/0x2e0
  pci_stop_bus_device+0xa0/0xd0
  pci_stop_and_remove_bus_device+0x28/0x40
  pci_hp_remove_devices+0xb0/0x150
  pci_hp_remove_devices+0x68/0x150
  eeh_handle_normal_event+0x140/0x580
  eeh_handle_event+0x174/0x360
  eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org

When was the bug introduced? ie. what commit does this fix?

Was it the original submission? So:

  Fixes: f204e0b8cedd ("cxl: Driver code for powernv PCIe based cards for userspace access")

Or does it depend on perst_reloads_same_image, so:

  Fixes: 13e68d8bd05c ("cxl: Allow the kernel to trust that an image won't change on PERST.")

Or something else?

cheers

Re: [v2] cxl: Avoid double free_irq() for psl,slice interrupts

From: Michael Ellerman <hidden>
Date: 2017-06-08 04:05:19

On Fri, 2017-06-02 at 16:56:48 UTC, Vaibhav Jain wrote:

During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
  free_irq+0x88/0xd0 (unreliable)
  cxl_unmap_irq+0x20/0x40 [cxl]
  cxl_native_release_psl_irq+0x78/0xd8 [cxl]
  pci_deconfigure_afu+0xac/0x110 [cxl]
  cxl_remove+0x104/0x210 [cxl]
  pci_device_remove+0x6c/0x110
  device_release_driver_internal+0x204/0x2e0
  pci_stop_bus_device+0xa0/0xd0
  pci_stop_and_remove_bus_device+0x28/0x40
  pci_hp_remove_devices+0xb0/0x150
  pci_hp_remove_devices+0x68/0x150
  eeh_handle_normal_event+0x140/0x580
  eeh_handle_event+0x174/0x360
  eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <redacted>
Reviewed-by: Andrew Donnellan <redacted>
Acked-by: Frederic Barrat <redacted>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/b3aa20ba2ba8072b73bd799605b8c9

cheers

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