diff options
| -rw-r--r-- | fs/cifs/misc.c | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 24f0a9d97ad8..2a930a752a78 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -478,25 +478,26 @@ checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length) if (((4 + len) & 0xFFFF) == (clc_len & 0xFFFF)) return 0; /* bcc wrapped */ } - cFYI(1, "Calculated size %d vs length %d mismatch for mid %d", + cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u", clc_len, 4 + len, smb->Mid); - /* Windows XP can return a few bytes too much, presumably - an illegal pad, at the end of byte range lock responses - so we allow for that three byte pad, as long as actual - received length is as long or longer than calculated length */ - /* We have now had to extend this more, since there is a - case in which it needs to be bigger still to handle a - malformed response to transact2 findfirst from WinXP when - access denied is returned and thus bcc and wct are zero - but server says length is 0x21 bytes too long as if the server - forget to reset the smb rfc1001 length when it reset the - wct and bcc to minimum size and drop the t2 parms and data */ - if ((4+len > clc_len) && (len <= clc_len + 512)) - return 0; - else { - cERROR(1, "RFC1001 size %d bigger than SMB for Mid=%d", + + if (4 + len < clc_len) { + cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u", len, smb->Mid); return 1; + } else if (len > clc_len + 512) { + /* + * Some servers (Windows XP in particular) send more + * data than the lengths in the SMB packet would + * indicate on certain calls (byte range locks and + * trans2 find first calls in particular). While the + * client can handle such a frame by ignoring the + * trailing data, we choose limit the amount of extra + * data to 512 bytes. + */ + cERROR(1, "RFC1001 size %u more than 512 bytes larger " + "than SMB for mid=%u", len, smb->Mid); + return 1; } } return 0; |