Merge tag '6.7-rc6-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client fixes from Steve French:

 - two multichannel reconnect fixes, one fixing an important refcounting
   problem that can lead to umount problems

 - atime fix

 - five fixes for various potential OOB accesses, including a CVE fix,
   and two additional fixes for problems pointed out by Robert Morris's
   fuzzing investigation

* tag '6.7-rc6-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: do not let cifs_chan_update_iface deallocate channels
  cifs: fix a pending undercount of srv_count
  fs: cifs: Fix atime update check
  smb: client: fix potential OOB in smb2_dump_detail()
  smb: client: fix potential OOB in cifs_dump_detail()
  smb: client: fix OOB in smbCalcSize()
  smb: client: fix OOB in SMB2_query_info_init()
  smb: client: fix OOB in cifsd when receiving compounded resps

1 files changed, 16 insertions, 9 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 8f6f0a38b886..66b310208545 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -403,8 +403,10 @@ smb2_dump_detail(void *buf, struct TCP_Server_Info *server)
 	cifs_server_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d\n",
 		 shdr->Command, shdr->Status, shdr->Flags, shdr->MessageId,
 		 shdr->Id.SyncId.ProcessId);
-	cifs_server_dbg(VFS, "smb buf %p len %u\n", buf,
-		 server->ops->calc_smb_size(buf));
+	if (!server->ops->check_message(buf, server->total_read, server)) {
+		cifs_server_dbg(VFS, "smb buf %p len %u\n", buf,
+				server->ops->calc_smb_size(buf));
+	}
 #endif
 }
 
@@ -5074,17 +5076,22 @@ smb3_handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 				NULL, 0, false);
 }
 
-static int
-smb2_next_header(char *buf)
+static int smb2_next_header(struct TCP_Server_Info *server, char *buf,
+			    unsigned int *noff)
 {
 	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
 	struct smb2_transform_hdr *t_hdr = (struct smb2_transform_hdr *)buf;
 
-	if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM)
-		return sizeof(struct smb2_transform_hdr) +
-		  le32_to_cpu(t_hdr->OriginalMessageSize);
-
-	return le32_to_cpu(hdr->NextCommand);
+	if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
+		*noff = le32_to_cpu(t_hdr->OriginalMessageSize);
+		if (unlikely(check_add_overflow(*noff, sizeof(*t_hdr), noff)))
+			return -EINVAL;
+	} else {
+		*noff = le32_to_cpu(hdr->NextCommand);
+	}
+	if (unlikely(*noff && *noff < MID_HEADER_SIZE(server)))
+		return -EINVAL;
+	return 0;
 }
 
 int cifs_sfu_make_node(unsigned int xid, struct inode *inode,