Commit a55f8023 authored by Richard Cheng's avatar Richard Cheng Committed by Jason Gunthorpe
Browse files

fwctl: Fix class init ordering to avoid NULL pointer dereference on device removal 

CXL is linked before fwctl in drivers/Makefile. Both use `module_init, so
`cxl_pci_driver_init()` runs first. When `cxl_pci_probe()` calls
`fwctl_register()` and then `device_add()`, fwctl_class is not yet
registered because fwctl_init() hasn't run, causing `class_to_subsys()` to
return NULL and skip knode_class initialization.

On device removal, `class_to_subsys()` returns non-NULL, and
`device_del()` calls `klist_del()` on the uninitialized knode, triggering
a NULL pointer dereference.

Fixes: 858ce2f5 ("cxl: Add FWCTL support to CXL")
Link: https://patch.msgid.link/r/20260409051902.40218-1-icheng@nvidia.com


Signed-off-by: default avatarRichard Cheng <icheng@nvidia.com>
Reviewed-by: default avatarKai-Heng Feng <kaihengf@nvidia.com>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 44230bb3

drivers/fwctl/main.c

+1 −1
Original line number Diff line number Diff line
@@ -415,7 +415,7 @@ static void __exit fwctl_exit(void) 
	unregister_chrdev_region(fwctl_dev, FWCTL_MAX_DEVICES);

}



module_init(fwctl_init);

subsys_initcall(fwctl_init);

module_exit(fwctl_exit);

MODULE_DESCRIPTION("fwctl device firmware access framework");

MODULE_LICENSE("GPL");