Patch "ntb: intel: Fix error handling in intel_ntb_pci_driver_init()" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ntb: intel: Fix error handling in intel_ntb_pci_driver_init()

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ntb-intel-fix-error-handling-in-intel_ntb_pci_driver.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7b9f5f4f4ba4a81054b4298375bdf38a3828e4c0
Author: Yuan Can <yuancan@xxxxxxxxxx>
Date:   Sat Nov 5 09:43:22 2022 +0000

    ntb: intel: Fix error handling in intel_ntb_pci_driver_init()
    
    [ Upstream commit 4c3c796aca02883ad35bb117468938cc4022ca41 ]
    
    A problem about ntb_hw_intel create debugfs failed is triggered with the
    following log given:
    
     [  273.112733] Intel(R) PCI-E Non-Transparent Bridge Driver 2.0
     [  273.115342] debugfs: Directory 'ntb_hw_intel' with parent '/' already present!
    
    The reason is that intel_ntb_pci_driver_init() returns
    pci_register_driver() directly without checking its return value, if
    pci_register_driver() failed, it returns without destroy the newly created
    debugfs, resulting the debugfs of ntb_hw_intel can never be created later.
    
     intel_ntb_pci_driver_init()
       debugfs_create_dir() # create debugfs directory
       pci_register_driver()
         driver_register()
           bus_add_driver()
             priv = kzalloc(...) # OOM happened
       # return without destroy debugfs directory
    
    Fix by removing debugfs when pci_register_driver() returns error.
    
    Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
    Signed-off-by: Yuan Can <yuancan@xxxxxxxxxx>
    Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx>
    Signed-off-by: Jon Mason <jdmason@xxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
index 84772013812bf..60a4ebc7bf35a 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen1.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -2064,12 +2064,17 @@ static struct pci_driver intel_ntb_pci_driver = {
 
 static int __init intel_ntb_pci_driver_init(void)
 {
+	int ret;
 	pr_info("%s %s\n", NTB_DESC, NTB_VER);
 
 	if (debugfs_initialized())
 		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 
-	return pci_register_driver(&intel_ntb_pci_driver);
+	ret = pci_register_driver(&intel_ntb_pci_driver);
+	if (ret)
+		debugfs_remove_recursive(debugfs_dir);
+
+	return ret;
 }
 module_init(intel_ntb_pci_driver_init);