erofs: fix incorrect early exits in volume label handling

Crafted EROFS images containing valid volume labels can trigger
incorrect early returns, leading to folio reference leaks.

However, this does not cause system crashes or other severe issues.

Fixes: 1cf12c717741 ("erofs: Add support for FS_IOC_GETFSLABEL")
Cc: stable@kernel.org
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index b54083128e0f4e0181b8c3499f5623bb8b8d6980..ee37628ec99fb3e7186d45d37906618855010c5c 100644 (file)
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -347,8 +347,10 @@ static int erofs_read_superblock(struct super_block *sb)
        if (dsb->volume_name[0]) {
                sbi->volume_name = kstrndup(dsb->volume_name,
                                            sizeof(dsb->volume_name), GFP_KERNEL);
-               if (!sbi->volume_name)
-                       return -ENOMEM;
+               if (!sbi->volume_name) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
        }
 
        /* parse on-disk compression configurations */