EDAC/igen6: Avoid segmentation fault on module unload

[ Upstream commit fefaae90398d38a1100ccd73b46ab55ff4610fba ]

The segmentation fault happens because:

During modprobe:
1. In igen6_probe(), igen6_pvt will be allocated with kzalloc()
2. In igen6_register_mci(), mci->pvt_info will point to
   &igen6_pvt->imc[mc]

During rmmod:
1. In mci_release() in edac_mc.c, it will kfree(mci->pvt_info)
2. In igen6_remove(), it will kfree(igen6_pvt);

Fix this issue by setting mci->pvt_info to NULL to avoid the double
kfree.

Fixes: 10590a9d4f23 ("EDAC/igen6: Add EDAC driver for Intel client SoCs using IBECC")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219360
Signed-off-by: Orange Kao <orange@aiven.io>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20241104124237.124109-2-orange@aiven.io
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/edac/igen6_edac.c b/drivers/edac/igen6_edac.c
index 74c5aad1f6081af174d2f02ddafde0a990dbbf5f..0ab8642c4e55a43f85ccc76fbc986e4699db2fe1 100644 (file)
--- a/drivers/edac/igen6_edac.c
+++ b/drivers/edac/igen6_edac.c
@@ -1075,6 +1075,7 @@ static int igen6_register_mci(int mc, u64 mchbar, struct pci_dev *pdev)
        imc->mci = mci;
        return 0;
 fail3:
+       mci->pvt_info = NULL;
        kfree(mci->ctl_name);
 fail2:
        edac_mc_free(mci);
@@ -1099,6 +1100,7 @@ static void igen6_unregister_mcis(void)
 
                edac_mc_del_mc(mci->pdev);
                kfree(mci->ctl_name);
+               mci->pvt_info = NULL;
                edac_mc_free(mci);
                iounmap(imc->window);
        }