NTB: Add Error Handling in ntb_device_setup

commit 3b12a0d15bd1559e72ad21d9d807fd2a6706f0ab upstream. If an error is encountered in ntb_device_setup, it is possible that the spci_cmd isn't populated. Writes to the offset can result in a NULL pointer dereference. This issue is easily encountered by running in NTB-RP mode, as it currently is not supported and will generate an error. To get around this issue, return if an error is encountered prior to attempting to write to the spci_cmd offset. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NTB: Add Error Handling in ntb_device_setup
commit 3b12a0d15bd1559e72ad21d9d807fd2a6706f0ab upstream. If an error is encountered in ntb_device_setup, it is possible that the spci_cmd isn't populated. Writes to the offset can result in a NULL pointer dereference. This issue is easily encountered by running in NTB-RP mode, as it currently is not supported and will generate an error. To get around this issue, return if an error is encountered prior to attempting to write to the spci_cmd offset. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jon Mason · Greg Kroah-Hartman
1 parent 24460c53b7
Showing 1 changed file with 4 additions and 1 deletions Side-by-side Diff
drivers/ntb/ntb_hw.c
@@ -644,10 +644,13 @@
 		rc = -ENODEV;
 	}
  
+	if (rc)
+		return rc;
+
 	/* Enable Bus Master and Memory Space on the secondary side */
 	writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER, ndev->reg_ofs.spci_cmd);
  
-	return rc;
+	return 0;
 }
  
 static void ntb_device_free(struct ntb_device *ndev)
...	...	@@ -644,10 +644,13 @@
644	644	rc = -ENODEV;
645	645	}
646	646
	647	+ if (rc)
	648	+ return rc;
	649	+
647	650	/* Enable Bus Master and Memory Space on the secondary side */
648	651	writew(PCI_COMMAND_MEMORY \| PCI_COMMAND_MASTER, ndev->reg_ofs.spci_cmd);
649	652
650		- return rc;
	653	+ return 0;
651	654	}
652	655
653	656	static void ntb_device_free(struct ntb_device *ndev)