Commit a09dc10d authored Feb 14, 2026 by Fedor Pchelkin Committed by Steve French Feb 14, 2026

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: d5fc1400 ("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>

parent 1aade89e

fs/smb/server/smb2pdu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)