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-rw-r--r--fs/cifs/connect.c47
1 files changed, 35 insertions, 12 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 47d8ff62368..8d6c17ab593 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -337,8 +337,13 @@ cifs_echo_request(struct work_struct *work)
struct TCP_Server_Info *server = container_of(work,
struct TCP_Server_Info, echo.work);
- /* no need to ping if we got a response recently */
- if (time_before(jiffies, server->lstrp + SMB_ECHO_INTERVAL - HZ))
+ /*
+ * We cannot send an echo until the NEGOTIATE_PROTOCOL request is
+ * done, which is indicated by maxBuf != 0. Also, no need to ping if
+ * we got a response recently
+ */
+ if (server->maxBuf == 0 ||
+ time_before(jiffies, server->lstrp + SMB_ECHO_INTERVAL - HZ))
goto requeue_echo;
rc = CIFSSMBEcho(server);
@@ -578,14 +583,23 @@ incomplete_rcv:
else if (reconnect == 1)
continue;
- length += 4; /* account for rfc1002 hdr */
+ total_read += 4; /* account for rfc1002 hdr */
+ dump_smb(smb_buffer, total_read);
- dump_smb(smb_buffer, length);
- if (checkSMB(smb_buffer, smb_buffer->Mid, total_read+4)) {
- cifs_dump_mem("Bad SMB: ", smb_buffer, 48);
- continue;
- }
+ /*
+ * 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.
+ *
+ * 48 bytes is enough to display the header and a little bit
+ * into the payload for debugging purposes.
+ */
+ length = checkSMB(smb_buffer, smb_buffer->Mid, total_read);
+ if (length != 0)
+ cifs_dump_mem("Bad SMB: ", smb_buffer,
+ min_t(unsigned int, total_read, 48));
mid_entry = NULL;
server->lstrp = jiffies;
@@ -597,7 +611,8 @@ incomplete_rcv:
if ((mid_entry->mid == smb_buffer->Mid) &&
(mid_entry->midState == MID_REQUEST_SUBMITTED) &&
(mid_entry->command == smb_buffer->Command)) {
- if (check2ndT2(smb_buffer,server->maxBuf) > 0) {
+ if (length == 0 &&
+ check2ndT2(smb_buffer, server->maxBuf) > 0) {
/* We have a multipart transact2 resp */
isMultiRsp = true;
if (mid_entry->resp_buf) {
@@ -632,12 +647,17 @@ incomplete_rcv:
mid_entry->resp_buf = smb_buffer;
mid_entry->largeBuf = isLargeBuf;
multi_t2_fnd:
- mid_entry->midState = MID_RESPONSE_RECEIVED;
- list_del_init(&mid_entry->qhead);
- mid_entry->callback(mid_entry);
+ if (length == 0)
+ mid_entry->midState =
+ MID_RESPONSE_RECEIVED;
+ else
+ mid_entry->midState =
+ MID_RESPONSE_MALFORMED;
#ifdef CONFIG_CIFS_STATS2
mid_entry->when_received = jiffies;
#endif
+ list_del_init(&mid_entry->qhead);
+ mid_entry->callback(mid_entry);
break;
}
mid_entry = NULL;
@@ -653,6 +673,9 @@ multi_t2_fnd:
else
smallbuf = NULL;
}
+ } else if (length != 0) {
+ /* response sanity checks failed */
+ continue;
} else if (!is_valid_oplock_break(smb_buffer, server) &&
!isMultiRsp) {
cERROR(1, "No task to wake, unknown frame received! "