From: Jeff Layton <jlayton@kernel.org>
Date: Sun, 31 Dec 2023 07:12:22 +0000 (+0900)
Subject: ksmbd: use F_SETLK when unlocking a file
X-Git-Tag: v6.1.71~99
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d847b75883419177e165353ffc4b8e6a436b3612;p=thirdparty%2Fkernel%2Fstable.git

ksmbd: use F_SETLK when unlocking a file

[ Upstream commit 7ecbe92696bb7fe32c80b6cf64736a0d157717a9 ]

ksmbd seems to be trying to use a cmd value of 0 when unlocking a file.
That activity requires a type of F_UNLCK with a cmd of F_SETLK. For
local POSIX locking, it doesn't matter much since vfs_lock_file ignores
@cmd, but filesystems that define their own ->lock operation expect to
see it set sanely.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index f5a46b6831636..554214fca5b78 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -6845,7 +6845,7 @@ static int smb2_set_flock_flags(struct file_lock *flock, int flags)
 	case SMB2_LOCKFLAG_UNLOCK:
 		ksmbd_debug(SMB, "received unlock request\n");
 		flock->fl_type = F_UNLCK;
-		cmd = 0;
+		cmd = F_SETLK;
 		break;
 	}
 
@@ -7228,7 +7228,7 @@ out:
 		rlock->fl_start = smb_lock->start;
 		rlock->fl_end = smb_lock->end;
 
-		rc = vfs_lock_file(filp, 0, rlock, NULL);
+		rc = vfs_lock_file(filp, F_SETLK, rlock, NULL);
 		if (rc)
 			pr_err("rollback unlock fail : %d\n", rc);