[PATCH v2] bcachefs: fix memleak in bch2_split_devs

[Su Yue]

The pointer dev_name can be modified by strseq(),
then causes the memleak:

Fix it by copy pointer dev_name at beginning and free the copied
pointer at end.

Signed-off-by: Su Yue <glass...@suse.com>
---
changelog:
v2:
    Remove the unnecessary assignment.    
---
 fs/bcachefs/util.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c
index c2ef7cddaa4f..f927c8a19e24 100644
--- a/fs/bcachefs/util.c
+++ b/fs/bcachefs/util.c
@@ -1186,7 +1186,9 @@ int bch2_split_devs(const char *_dev_name, darray_str 
*ret)
 {
        darray_init(ret);
 
-       char *dev_name = kstrdup(_dev_name, GFP_KERNEL), *s = dev_name;
+       char *dev_name, *s, *orig;
+
+       dev_name = orig = kstrdup(_dev_name, GFP_KERNEL);
        if (!dev_name)
                return -ENOMEM;
 
@@ -1201,10 +1203,10 @@ int bch2_split_devs(const char *_dev_name, darray_str 
*ret)
                }
        }
 
-       kfree(dev_name);
+       kfree(orig);
        return 0;
 err:
        bch2_darray_str_exit(ret);
-       kfree(dev_name);
+       kfree(orig);
        return -ENOMEM;
 }
-- 
2.43.0