Merge tag '6.4-rc4-smb3-server-fixes' of git://git.samba.org/ksmbd

torvalds · torvalds · commit 882800375939 · 2023-06-01T08:27:34.000-04:00
Pull smb server fixes from Steve French:
 "Eight server fixes (most also for stable):

   - Two fixes for uninitialized pointer reads (rename and link)

   - Fix potential UAF in oplock break

   - Two fixes for potential out of bound reads in negotiate

   - Fix crediting bug

   - Two fixes for xfstests (allocation size fix for test 694 and lookup
     issue shown by test 464)"

* tag '6.4-rc4-smb3-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: call putname after using the last component
  ksmbd: fix incorrect AllocationSize set in smb2_get_info
  ksmbd: fix UAF issue from opinfo-&gt;conn
  ksmbd: fix multiple out-of-bounds read during context decoding
  ksmbd: fix slab-out-of-bounds read in smb2_handle_negotiate
  ksmbd: fix credit count leakage
  ksmbd: fix uninitialized pointer read in smb2_create_link()
  ksmbd: fix uninitialized pointer read in ksmbd_vfs_rename()
diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c
@@ -157,13 +157,42 @@ static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci)
 	rcu_read_lock();
 	opinfo = list_first_or_null_rcu(&ci->m_op_list, struct oplock_info,
 					op_entry);
-	if (opinfo && !atomic_inc_not_zero(&opinfo->refcount))
-		opinfo = NULL;
+	if (opinfo) {
+		if (!atomic_inc_not_zero(&opinfo->refcount))
+			opinfo = NULL;
+		else {
+			atomic_inc(&opinfo->conn->r_count);
+			if (ksmbd_conn_releasing(opinfo->conn)) {
+				atomic_dec(&opinfo->conn->r_count);
+				atomic_dec(&opinfo->refcount);
+				opinfo = NULL;
+			}
+		}
+	}
+
 	rcu_read_unlock();
 
 	return opinfo;
 }
 
+static void opinfo_conn_put(struct oplock_info *opinfo)
+{
+	struct ksmbd_conn *conn;
+
+	if (!opinfo)
+		return;
+
+	conn = opinfo->conn;
+	/*
+	 * Checking waitqueue to dropping pending requests on
+	 * disconnection. waitqueue_active is safe because it
+	 * uses atomic operation for condition.
+	 */
+	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
+		wake_up(&conn->r_count_q);
+	opinfo_put(opinfo);
+}
+
 void opinfo_put(struct oplock_info *opinfo)
 {
 	if (!atomic_dec_and_test(&opinfo->refcount))
@@ -666,13 +695,6 @@ static void __smb2_oplock_break_noti(struct work_struct *wk)
 
 out:
 	ksmbd_free_work_struct(work);
-	/*
-	 * Checking waitqueue to dropping pending requests on
-	 * disconnection. waitqueue_active is safe because it
-	 * uses atomic operation for condition.
-	 */
-	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
-		wake_up(&conn->r_count_q);
 }
 
 /**
@@ -706,7 +728,6 @@ static int smb2_oplock_break_noti(struct oplock_info *opinfo)
 	work->conn = conn;
 	work->sess = opinfo->sess;
 
-	atomic_inc(&conn->r_count);
 	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
 		INIT_WORK(&work->work, __smb2_oplock_break_noti);
 		ksmbd_queue_work(work);
@@ -776,13 +797,6 @@ static void __smb2_lease_break_noti(struct work_struct *wk)
 
 out:
 	ksmbd_free_work_struct(work);
-	/*
-	 * Checking waitqueue to dropping pending requests on
-	 * disconnection. waitqueue_active is safe because it
-	 * uses atomic operation for condition.
-	 */
-	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
-		wake_up(&conn->r_count_q);
 }
 
 /**
@@ -822,7 +836,6 @@ static int smb2_lease_break_noti(struct oplock_info *opinfo)
 	work->conn = conn;
 	work->sess = opinfo->sess;
 
-	atomic_inc(&conn->r_count);
 	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
 		list_for_each_safe(tmp, t, &opinfo->interim_list) {
 			struct ksmbd_work *in_work;
@@ -1144,28 +1157,30 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid,
 	}
 	prev_opinfo = opinfo_get_list(ci);
 	if (!prev_opinfo ||
-	    (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx))
+	    (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx)) {
+		opinfo_conn_put(prev_opinfo);
 		goto set_lev;
+	}
 	prev_op_has_lease = prev_opinfo->is_lease;
 	if (prev_op_has_lease)
 		prev_op_state = prev_opinfo->o_lease->state;
 
 	if (share_ret < 0 &&
 	    prev_opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
 		err = share_ret;
-		opinfo_put(prev_opinfo);
+		opinfo_conn_put(prev_opinfo);
 		goto err_out;
 	}
 
 	if (prev_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH &&
 	    prev_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
-		opinfo_put(prev_opinfo);
+		opinfo_conn_put(prev_opinfo);
 		goto op_break_not_needed;
 	}
 
 	list_add(&work->interim_entry, &prev_opinfo->interim_list);
 	err = oplock_break(prev_opinfo, SMB2_OPLOCK_LEVEL_II);
-	opinfo_put(prev_opinfo);
+	opinfo_conn_put(prev_opinfo);
 	if (err == -ENOENT)
 		goto set_lev;
 	/* Check all oplock was freed by close */
@@ -1228,14 +1243,14 @@ static void smb_break_all_write_oplock(struct ksmbd_work *work,
 		return;
 	if (brk_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH &&
 	    brk_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
-		opinfo_put(brk_opinfo);
+		opinfo_conn_put(brk_opinfo);
 		return;
 	}
 
 	brk_opinfo->open_trunc = is_trunc;
 	list_add(&work->interim_entry, &brk_opinfo->interim_list);
 	oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II);
-	opinfo_put(brk_opinfo);
+	opinfo_conn_put(brk_opinfo);
 }
 
 /**
@@ -1263,6 +1278,13 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp,
 	list_for_each_entry_rcu(brk_op, &ci->m_op_list, op_entry) {
 		if (!atomic_inc_not_zero(&brk_op->refcount))
 			continue;
+
+		atomic_inc(&brk_op->conn->r_count);
+		if (ksmbd_conn_releasing(brk_op->conn)) {
+			atomic_dec(&brk_op->conn->r_count);
+			continue;
+		}
+
 		rcu_read_unlock();
 		if (brk_op->is_lease && (brk_op->o_lease->state &
 		    (~(SMB2_LEASE_READ_CACHING_LE |
@@ -1292,7 +1314,7 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp,
 		brk_op->open_trunc = is_trunc;
 		oplock_break(brk_op, SMB2_OPLOCK_LEVEL_NONE);
 next:
-		opinfo_put(brk_op);
+		opinfo_conn_put(brk_op);
 		rcu_read_lock();
 	}
 	rcu_read_unlock();
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
@@ -326,13 +326,9 @@ int smb2_set_rsp_credits(struct ksmbd_work *work)
 	if (hdr->Command == SMB2_NEGOTIATE)
 		aux_max = 1;
 	else
-		aux_max = conn->vals->max_credits - credit_charge;
+		aux_max = conn->vals->max_credits - conn->total_credits;
 	credits_granted = min_t(unsigned short, credits_requested, aux_max);
 
-	if (conn->vals->max_credits - conn->total_credits < credits_granted)
-		credits_granted = conn->vals->max_credits -
-			conn->total_credits;
-
 	conn->total_credits += credits_granted;
 	work->credits_granted += credits_granted;
 
@@ -849,13 +845,14 @@ static void assemble_neg_contexts(struct ksmbd_conn *conn,
 
 static __le32 decode_preauth_ctxt(struct ksmbd_conn *conn,
 				  struct smb2_preauth_neg_context *pneg_ctxt,
-				  int len_of_ctxts)
+				  int ctxt_len)
 {
 	/*
 	 * sizeof(smb2_preauth_neg_context) assumes SMB311_SALT_SIZE Salt,
 	 * which may not be present. Only check for used HashAlgorithms[1].
 	 */
-	if (len_of_ctxts < MIN_PREAUTH_CTXT_DATA_LEN)
+	if (ctxt_len <
+	    sizeof(struct smb2_neg_context) + MIN_PREAUTH_CTXT_DATA_LEN)
 		return STATUS_INVALID_PARAMETER;
 
 	if (pneg_ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
@@ -867,15 +864,23 @@ static __le32 decode_preauth_ctxt(struct ksmbd_conn *conn,
 
 static void decode_encrypt_ctxt(struct ksmbd_conn *conn,
 				struct smb2_encryption_neg_context *pneg_ctxt,
-				int len_of_ctxts)
+				int ctxt_len)
 {
-	int cph_cnt = le16_to_cpu(pneg_ctxt->CipherCount);
-	int i, cphs_size = cph_cnt * sizeof(__le16);
+	int cph_cnt;
+	int i, cphs_size;
+
+	if (sizeof(struct smb2_encryption_neg_context) > ctxt_len) {
+		pr_err("Invalid SMB2_ENCRYPTION_CAPABILITIES context size\n");
+		return;
+	}
 
 	conn->cipher_type = 0;
 
+	cph_cnt = le16_to_cpu(pneg_ctxt->CipherCount);
+	cphs_size = cph_cnt * sizeof(__le16);
+
 	if (sizeof(struct smb2_encryption_neg_context) + cphs_size >
-	    len_of_ctxts) {
+	    ctxt_len) {
 		pr_err("Invalid cipher count(%d)\n", cph_cnt);
 		return;
 	}
@@ -923,15 +928,22 @@ static void decode_compress_ctxt(struct ksmbd_conn *conn,
 
 static void decode_sign_cap_ctxt(struct ksmbd_conn *conn,
 				 struct smb2_signing_capabilities *pneg_ctxt,
-				 int len_of_ctxts)
+				 int ctxt_len)
 {
-	int sign_algo_cnt = le16_to_cpu(pneg_ctxt->SigningAlgorithmCount);
-	int i, sign_alos_size = sign_algo_cnt * sizeof(__le16);
+	int sign_algo_cnt;
+	int i, sign_alos_size;
+
+	if (sizeof(struct smb2_signing_capabilities) > ctxt_len) {
+		pr_err("Invalid SMB2_SIGNING_CAPABILITIES context length\n");
+		return;
+	}
 
 	conn->signing_negotiated = false;
+	sign_algo_cnt = le16_to_cpu(pneg_ctxt->SigningAlgorithmCount);
+	sign_alos_size = sign_algo_cnt * sizeof(__le16);
 
 	if (sizeof(struct smb2_signing_capabilities) + sign_alos_size >
-	    len_of_ctxts) {
+	    ctxt_len) {
 		pr_err("Invalid signing algorithm count(%d)\n", sign_algo_cnt);
 		return;
 	}
@@ -969,18 +981,16 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn,
 	len_of_ctxts = len_of_smb - offset;
 
 	while (i++ < neg_ctxt_cnt) {
-		int clen;
-
-		/* check that offset is not beyond end of SMB */
-		if (len_of_ctxts == 0)
-			break;
+		int clen, ctxt_len;
 
 		if (len_of_ctxts < sizeof(struct smb2_neg_context))
 			break;
 
 		pctx = (struct smb2_neg_context *)((char *)pctx + offset);
 		clen = le16_to_cpu(pctx->DataLength);
-		if (clen + sizeof(struct smb2_neg_context) > len_of_ctxts)
+		ctxt_len = clen + sizeof(struct smb2_neg_context);
+
+		if (ctxt_len > len_of_ctxts)
 			break;
 
 		if (pctx->ContextType == SMB2_PREAUTH_INTEGRITY_CAPABILITIES) {
@@ -991,7 +1001,7 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn,
 
 			status = decode_preauth_ctxt(conn,
 						     (struct smb2_preauth_neg_context *)pctx,
-						     len_of_ctxts);
+						     ctxt_len);
 			if (status != STATUS_SUCCESS)
 				break;
 		} else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES) {
@@ -1002,7 +1012,7 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn,
 
 			decode_encrypt_ctxt(conn,
 					    (struct smb2_encryption_neg_context *)pctx,
-					    len_of_ctxts);
+					    ctxt_len);
 		} else if (pctx->ContextType == SMB2_COMPRESSION_CAPABILITIES) {
 			ksmbd_debug(SMB,
 				    "deassemble SMB2_COMPRESSION_CAPABILITIES context\n");
@@ -1021,9 +1031,10 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn,
 		} else if (pctx->ContextType == SMB2_SIGNING_CAPABILITIES) {
 			ksmbd_debug(SMB,
 				    "deassemble SMB2_SIGNING_CAPABILITIES context\n");
+
 			decode_sign_cap_ctxt(conn,
 					     (struct smb2_signing_capabilities *)pctx,
-					     len_of_ctxts);
+					     ctxt_len);
 		}
 
 		/* offsets must be 8 byte aligned */
@@ -1057,16 +1068,16 @@ int smb2_handle_negotiate(struct ksmbd_work *work)
 		return rc;
 	}
 
-	if (req->DialectCount == 0) {
-		pr_err("malformed packet\n");
+	smb2_buf_len = get_rfc1002_len(work->request_buf);
+	smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects);
+	if (smb2_neg_size > smb2_buf_len) {
 		rsp->hdr.Status = STATUS_INVALID_PARAMETER;
 		rc = -EINVAL;
 		goto err_out;
 	}
 
-	smb2_buf_len = get_rfc1002_len(work->request_buf);
-	smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects);
-	if (smb2_neg_size > smb2_buf_len) {
+	if (req->DialectCount == 0) {
+		pr_err("malformed packet\n");
 		rsp->hdr.Status = STATUS_INVALID_PARAMETER;
 		rc = -EINVAL;
 		goto err_out;
@@ -4358,21 +4369,6 @@ static int get_file_basic_info(struct smb2_query_info_rsp *rsp,
 	return 0;
 }
 
-static unsigned long long get_allocation_size(struct inode *inode,
-					      struct kstat *stat)
-{
-	unsigned long long alloc_size = 0;
-
-	if (!S_ISDIR(stat->mode)) {
-		if ((inode->i_blocks << 9) <= stat->size)
-			alloc_size = stat->size;
-		else
-			alloc_size = inode->i_blocks << 9;
-	}
-
-	return alloc_size;
-}
-
 static void get_file_standard_info(struct smb2_query_info_rsp *rsp,
 				   struct ksmbd_file *fp, void *rsp_org)
 {
@@ -4387,7 +4383,7 @@ static void get_file_standard_info(struct smb2_query_info_rsp *rsp,
 	sinfo = (struct smb2_file_standard_info *)rsp->Buffer;
 	delete_pending = ksmbd_inode_pending_delete(fp);
 
-	sinfo->AllocationSize = cpu_to_le64(get_allocation_size(inode, &stat));
+	sinfo->AllocationSize = cpu_to_le64(inode->i_blocks << 9);
 	sinfo->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
 	sinfo->NumberOfLinks = cpu_to_le32(get_nlink(&stat) - delete_pending);
 	sinfo->DeletePending = delete_pending;
@@ -4452,7 +4448,7 @@ static int get_file_all_info(struct ksmbd_work *work,
 	file_info->Attributes = fp->f_ci->m_fattr;
 	file_info->Pad1 = 0;
 	file_info->AllocationSize =
-		cpu_to_le64(get_allocation_size(inode, &stat));
+		cpu_to_le64(inode->i_blocks << 9);
 	file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
 	file_info->NumberOfLinks =
 			cpu_to_le32(get_nlink(&stat) - delete_pending);
@@ -4641,7 +4637,7 @@ static int get_file_network_open_info(struct smb2_query_info_rsp *rsp,
 	file_info->ChangeTime = cpu_to_le64(time);
 	file_info->Attributes = fp->f_ci->m_fattr;
 	file_info->AllocationSize =
-		cpu_to_le64(get_allocation_size(inode, &stat));
+		cpu_to_le64(inode->i_blocks << 9);
 	file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
 	file_info->Reserved = cpu_to_le32(0);
 	rsp->OutputBufferLength =
@@ -5506,7 +5502,7 @@ static int smb2_create_link(struct ksmbd_work *work,
 {
 	char *link_name = NULL, *target_name = NULL, *pathname = NULL;
 	struct path path;
-	bool file_present = true;
+	bool file_present = false;
 	int rc;
 
 	if (buf_len < (u64)sizeof(struct smb2_file_link_info) +
@@ -5539,8 +5535,8 @@ static int smb2_create_link(struct ksmbd_work *work,
 	if (rc) {
 		if (rc != -ENOENT)
 			goto out;
-		file_present = false;
-	}
+	} else
+		file_present = true;
 
 	if (file_info->ReplaceIfExists) {
 		if (file_present) {
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
