diff options
Diffstat (limited to 'fs/cifs/smb2misc.c')
| -rw-r--r-- | fs/cifs/smb2misc.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 5406e95f5d92..68ea8491c160 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -93,6 +93,43 @@ static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { /* SMB2_OPLOCK_BREAK */ cpu_to_le16(24) }; +#ifdef CONFIG_CIFS_SMB311 +static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len, __u32 non_ctxlen, + size_t hdr_preamble_size) +{ + __u16 neg_count; + __u32 nc_offset, size_of_pad_before_neg_ctxts; + struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr; + + /* Negotiate contexts are only valid for latest dialect SMB3.11 */ + neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount); + if ((neg_count == 0) || + (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID))) + return 0; + + /* Make sure that negotiate contexts start after gss security blob */ + nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset); + if (nc_offset < non_ctxlen - hdr_preamble_size /* RFC1001 len */) { + printk_once(KERN_WARNING "invalid negotiate context offset\n"); + return 0; + } + size_of_pad_before_neg_ctxts = nc_offset - + (non_ctxlen - hdr_preamble_size); + + /* Verify that at least minimal negotiate contexts fit within frame */ + if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) { + printk_once(KERN_WARNING "negotiate context goes beyond end\n"); + return 0; + } + + cifs_dbg(FYI, "length of negcontexts %d pad %d\n", + len - nc_offset, size_of_pad_before_neg_ctxts); + + /* length of negcontexts including pad from end of sec blob to them */ + return (len - nc_offset) + size_of_pad_before_neg_ctxts; +} +#endif /* CIFS_SMB311 */ + int smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) { @@ -198,6 +235,11 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) clc_len = smb2_calc_size(hdr); +#ifdef CONFIG_CIFS_SMB311 + if (shdr->Command == SMB2_NEGOTIATE) + clc_len += get_neg_ctxt_len(hdr, len, clc_len, + srvr->vals->header_preamble_size); +#endif /* SMB311 */ if (srvr->vals->header_preamble_size + len != clc_len) { cifs_dbg(FYI, "Calculated size %u length %zu mismatch mid %llu\n", clc_len, srvr->vals->header_preamble_size + len, mid); |