btrfs: fix double free in create_space_info() error path

When kobject_init_and_add() fails, the call chain is:

create_space_info()
-> btrfs_sysfs_add_space_info_type()
-> kobject_init_and_add()
-> failure
-> kobject_put(&space_info->kobj)
-> space_info_release()
-> kfree(space_info)

Then control returns to create_space_info():

btrfs_sysfs_add_space_info_type() returns error
-> goto out_free
-> kfree(space_info)

This causes a double free.

Keep the direct kfree(space_info) for the earlier failure path, but
after btrfs_sysfs_add_space_info_type() has called kobject_put(), let
the kobject release callback handle the cleanup.

Fixes: a11224a016d6d ("btrfs: fix memory leaks in create_space_info() error paths")
CC: stable@vger.kernel.org # 6.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 8278e7998bc9a0b8848cd53f4b445ab6faef27e1..f0436eea15445b978fa6098041fae450fbc6c184 100644 (file)
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -320,7 +320,7 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags)
 
        ret = btrfs_sysfs_add_space_info_type(space_info);
        if (ret)
-               goto out_free;
+               return ret;
 
        list_add(&space_info->list, &info->space_info);
        if (flags & BTRFS_BLOCK_GROUP_DATA)