[PATCH] resource: Fix resource leak in get_free_mem_region()

[Li Zhijian]

The leak is detected by the kernel memory leak detector (`kmemleak`)
following a `cxl create-region` failure:

 cxl_acpi ACPI0017:00: decoder0.0: created region2
 cxl region2: HPA allocation error (-34) for size:0x0000000100000000 in CXL Window 0 [mem 0xa90000000-0x1a8fffffff flags 0x200]
 kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

    __kmalloc_cache_noprof+0x28c/0x350
    get_free_mem_region+0x45/0x380
    alloc_free_mem_region+0x1d/0x30
    size_store+0x180/0x290 [cxl_core]
    kernfs_fop_write_iter+0x13f/0x1e0
    vfs_write+0x37c/0x540
    ksys_write+0x68/0xe0
    do_syscall_64+0x6e/0x190
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: 14b80582c43e ("resource: Introduce alloc_free_mem_region()")
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
 kernel/resource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/resource.c b/kernel/resource.c
index 12004452d999..aa0b1da143eb 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -2000,6 +2000,8 @@ get_free_mem_region(struct device *dev, struct resource *base,
 		devres_free(dr);
 	} else if (dev)
 		devm_release_action(dev, remove_free_mem_region, res);
+	else
+		free_resource(res);
 
 	return ERR_PTR(-ERANGE);
 }
-- 
2.47.0