diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index fdd8452b8450..8859da70cb06 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1039,19 +1039,18 @@ int cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid) { char *buf = server->large_buf ? server->bigbuf : server->smallbuf; - int length; + int rc; /* * We know that we received enough to get to the MID as we * checked the pdu_length earlier. Now check to see - * if the rest of the header is OK. We borrow the length - * var for the rest of the loop to avoid a new stack var. + * if the rest of the header is OK. * * 48 bytes is enough to display the header and a little bit * into the payload for debugging purposes. */ - length = server->ops->check_message(buf, server->total_read, server); - if (length != 0) + rc = server->ops->check_message(buf, server->total_read, server); + if (rc) cifs_dump_mem("Bad SMB: ", buf, min_t(unsigned int, server->total_read, 48)); @@ -1066,9 +1065,9 @@ cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid) return -1; if (!mid) - return length; + return rc; - handle_mid(mid, server, buf, length); + handle_mid(mid, server, buf, rc); return 0; } diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index db0f27fd373b..818cc4dee0e2 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -132,15 +132,15 @@ static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len, } int -smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) +smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server) { struct smb2_hdr *shdr = (struct smb2_hdr *)buf; struct smb2_pdu *pdu = (struct smb2_pdu *)shdr; - __u64 mid; - __u32 clc_len; /* calculated length */ - int command; - int pdu_size = sizeof(struct smb2_pdu); int hdr_size = sizeof(struct smb2_hdr); + int pdu_size = sizeof(struct smb2_pdu); + int command; + __u32 calc_len; /* calculated length */ + __u64 mid; /* * Add function to do table lookup of StructureSize by command @@ -154,7 +154,7 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) /* decrypt frame now that it is completely read in */ spin_lock(&cifs_tcp_ses_lock); - list_for_each_entry(iter, &srvr->smb_ses_list, smb_ses_list) { + list_for_each_entry(iter, &server->smb_ses_list, smb_ses_list) { if (iter->Suid == le64_to_cpu(thdr->SessionId)) { ses = iter; break; @@ -221,30 +221,33 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) } } - clc_len = smb2_calc_size(buf, srvr); + calc_len = smb2_calc_size(buf, server); - if (shdr->Command == SMB2_NEGOTIATE) - clc_len += get_neg_ctxt_len(shdr, len, clc_len); + /* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might + * be 0, and not a real miscalculation */ + if (command == SMB2_IOCTL_HE && calc_len == 0) + return 0; - if (len != clc_len) { - cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n", - clc_len, len, mid); + if (command == SMB2_NEGOTIATE_HE) + calc_len += get_neg_ctxt_len(shdr, len, calc_len); + + if (len != calc_len) { /* create failed on symlink */ if (command == SMB2_CREATE_HE && shdr->Status == STATUS_STOPPED_ON_SYMLINK) return 0; /* Windows 7 server returns 24 bytes more */ - if (clc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE) + if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE) return 0; /* server can return one byte more due to implied bcc[0] */ - if (clc_len == len + 1) + if (calc_len == len + 1) return 0; /* * Some windows servers (win2016) will pad also the final * PDU in a compound to 8 bytes. */ - if (((clc_len + 7) & ~7) == len) + if (((calc_len + 7) & ~7) == len) return 0; /* @@ -253,12 +256,18 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) * SMB2/SMB3 frame length (header + smb2 response specific data) * Some windows servers also pad up to 8 bytes when compounding. */ - if (clc_len < len) + if (calc_len < len) return 0; - pr_warn_once( - "srv rsp too short, len %d not %d. cmd:%d mid:%llu\n", - len, clc_len, command, mid); + /* Only log a message if len was really miscalculated */ + if (unlikely(cifsFYI)) + cifs_dbg(FYI, "Server response too short: calculated " + "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n", + calc_len, len, command, mid); + else + pr_warn("Server response too short: calculated length " + "%u doesn't match read length %u (cmd=%d, mid=%llu)\n", + calc_len, len, command, mid); return 1; }