ksmbd: call ksmbd_vfs_kern_path_end_removing() on some error paths

There are two places where ksmbd_vfs_kern_path_end_removing() needs to be
called in order to balance what the corresponding successful call to
ksmbd_vfs_kern_path_start_removing() has done, i.e. drop inode locks and
put the taken references.  Otherwise there might be potential deadlocks
and unbalanced locks which are caught like:

BUG: workqueue leaked lock or atomic: kworker/5:21/0x00000000/7596
     last function: handle_ksmbd_work
2 locks held by kworker/5:21/7596:
 #0: ffff8881051ae448 (sb_writers#3){.+.+}-{0:0}, at: ksmbd_vfs_kern_path_locked+0x142/0x660
 #1: ffff888130e966c0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: ksmbd_vfs_kern_path_locked+0x17d/0x660
CPU: 5 PID: 7596 Comm: kworker/5:21 Not tainted 6.1.162-00456-gc29b353f383b #138
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
Workqueue: ksmbd-io handle_ksmbd_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x44/0x5b
 process_one_work.cold+0x57/0x5c
 worker_thread+0x82/0x600
 kthread+0x153/0x190
 ret_from_fork+0x22/0x30
 </TASK>

Found by Linux Verification Center (linuxtesting.org).

Fixes: d5fc1400a3 ("smb/server: avoid deadlock when linking with ReplaceIfExists")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Fedor Pchelkin 2026-02-14 18:45:14 +03:00 committed by Steve French
parent 1aade89ecc
commit a09dc10d13

View file

@ -6115,14 +6115,14 @@ static int smb2_create_link(struct ksmbd_work *work,
rc = -EINVAL;
ksmbd_debug(SMB, "cannot delete %s\n",
link_name);
goto out;
}
} else {
rc = -EEXIST;
ksmbd_debug(SMB, "link already exists\n");
goto out;
}
ksmbd_vfs_kern_path_end_removing(&path);
if (rc)
goto out;
}
rc = ksmbd_vfs_link(work, target_name, link_name);
if (rc)