From: Namjae Jeon <linkinjeon@kernel.org>
Date: Mon, 7 Jul 2025 22:47:40 +0000 (+0900)
Subject: ksmbd: fix potential use-after-free in oplock/lease break ack
X-Git-Tag: v6.16-rc6~8^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=50f930db22365738d9387c974416f38a06e8057e;p=thirdparty%2Fkernel%2Flinux.git

ksmbd: fix potential use-after-free in oplock/lease break ack

If ksmbd_iov_pin_rsp return error, use-after-free can happen by
accessing opinfo->state and opinfo_put and ksmbd_fd_put could
called twice.

Reported-by: Ziyan Xu <research@securitygossip.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index fafa86273f121..63d17cea2e95f 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -8573,11 +8573,6 @@ static void smb20_oplock_break_ack(struct ksmbd_work *work)
 		goto err_out;
 	}
 
-	opinfo->op_state = OPLOCK_STATE_NONE;
-	wake_up_interruptible_all(&opinfo->oplock_q);
-	opinfo_put(opinfo);
-	ksmbd_fd_put(work, fp);
-
 	rsp->StructureSize = cpu_to_le16(24);
 	rsp->OplockLevel = rsp_oplevel;
 	rsp->Reserved = 0;
@@ -8585,16 +8580,15 @@ static void smb20_oplock_break_ack(struct ksmbd_work *work)
 	rsp->VolatileFid = volatile_id;
 	rsp->PersistentFid = persistent_id;
 	ret = ksmbd_iov_pin_rsp(work, rsp, sizeof(struct smb2_oplock_break));
-	if (!ret)
-		return;
-
+	if (ret) {
 err_out:
+		smb2_set_err_rsp(work);
+	}
+
 	opinfo->op_state = OPLOCK_STATE_NONE;
 	wake_up_interruptible_all(&opinfo->oplock_q);
-
 	opinfo_put(opinfo);
 	ksmbd_fd_put(work, fp);
-	smb2_set_err_rsp(work);
 }
 
 static int check_lease_state(struct lease *lease, __le32 req_state)
@@ -8724,11 +8718,6 @@ static void smb21_lease_break_ack(struct ksmbd_work *work)
 	}
 
 	lease_state = lease->state;
-	opinfo->op_state = OPLOCK_STATE_NONE;
-	wake_up_interruptible_all(&opinfo->oplock_q);
-	atomic_dec(&opinfo->breaking_cnt);
-	wake_up_interruptible_all(&opinfo->oplock_brk);
-	opinfo_put(opinfo);
 
 	rsp->StructureSize = cpu_to_le16(36);
 	rsp->Reserved = 0;
@@ -8737,16 +8726,16 @@ static void smb21_lease_break_ack(struct ksmbd_work *work)
 	rsp->LeaseState = lease_state;
 	rsp->LeaseDuration = 0;
 	ret = ksmbd_iov_pin_rsp(work, rsp, sizeof(struct smb2_lease_ack));
-	if (!ret)
-		return;
-
+	if (ret) {
 err_out:
+		smb2_set_err_rsp(work);
+	}
+
+	opinfo->op_state = OPLOCK_STATE_NONE;
 	wake_up_interruptible_all(&opinfo->oplock_q);
 	atomic_dec(&opinfo->breaking_cnt);
 	wake_up_interruptible_all(&opinfo->oplock_brk);
-
 	opinfo_put(opinfo);
-	smb2_set_err_rsp(work);
 }
 
 /**