[PATCH 5.4 087/155] ceph: fix memory leak in ceph_cleanup_snapid_map()

[Greg Kroah-Hartman]

From: Luis Henriques <lhenriques@xxxxxxxx>

commit c8d6ee01449cd0d2f30410681cccb616a88f50b1 upstream.

kmemleak reports the following memory leak:

unreferenced object 0xffff88821feac8a0 (size 96):
  comm "kworker/1:0", pid 17, jiffies 4294896362 (age 20.512s)
  hex dump (first 32 bytes):
    a0 c8 ea 1f 82 88 ff ff 00 c9 ea 1f 82 88 ff ff  ................
    00 00 00 00 00 00 00 00 00 01 00 00 00 00 ad de  ................
  backtrace:
    [<00000000b3ea77fb>] ceph_get_snapid_map+0x75/0x2a0
    [<00000000d4060942>] fill_inode+0xb26/0x1010
    [<0000000049da6206>] ceph_readdir_prepopulate+0x389/0xc40
    [<00000000e2fe2549>] dispatch+0x11ab/0x1521
    [<000000007700b894>] ceph_con_workfn+0xf3d/0x3240
    [<0000000039138a41>] process_one_work+0x24d/0x590
    [<00000000eb751f34>] worker_thread+0x4a/0x3d0
    [<000000007e8f0d42>] kthread+0xfb/0x130
    [<00000000d49bd1fa>] ret_from_fork+0x3a/0x50

A kfree is missing while looping the 'to_free' list of ceph_snapid_map
objects.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 75c9627efb72 ("ceph: map snapid to anonymous bdev ID")
Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/ceph/snap.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -1155,5 +1155,6 @@ void ceph_cleanup_snapid_map(struct ceph
 			pr_err("snapid map %llx -> %x still in use\n",
 			       sm->snap, sm->dev);
 		}
+		kfree(sm);
 	}
 }