On 2/27/18 12:54 AM, Greg Kroah-Hartman wrote: > On Mon, Feb 26, 2018 at 07:44:28PM -0800, Srivatsa S. Bhat wrote: >> On 1/3/18 6:15 PM, Srivatsa S. Bhat wrote: >>> On 11/1/17 8:18 AM, Greg Kroah-Hartman wrote: >>>> On Tue, Oct 31, 2017 at 03:02:11PM +0200, Thomas Backlund wrote: >>>>> Den 31.10.2017 kl. 11:55, skrev Greg Kroah-Hartman: >>>>>> 4.13-stable review patch. If anyone has any objections, please let me know. >>>>>> >>>>>> ------------------ >>>>>> >>>>>> From: Steve French <smfrench@xxxxxxxxx> >>>>>> >>>>>> commit 4587eee04e2ac7ac3ac9fa2bc164fb6e548f99cd upstream. >>>>>> >>>>>> According to MS-SMB2 3.2.55 validate_negotiate request must >>>>>> always be signed. Some Windows can fail the request if you send it unsigned >>>>>> >>>>>> See kernel bugzilla bug 197311 >>>>>> >>>>>> Acked-by: Ronnie Sahlberg <lsahlber.redhat.com> >>>>>> Signed-off-by: Steve French <smfrench@xxxxxxxxx> >>>>>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> >>>>>> >>>>>> --- >>>>>> fs/cifs/smb2pdu.c | 3 +++ >>>>>> 1 file changed, 3 insertions(+) >>>>>> >>>>>> --- a/fs/cifs/smb2pdu.c >>>>>> +++ b/fs/cifs/smb2pdu.c >>>>>> @@ -1963,6 +1963,9 @@ SMB2_ioctl(const unsigned int xid, struc >>>>>> } else >>>>>> iov[0].iov_len = get_rfc1002_length(req) + 4; >>>>>> + /* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */ >>>>>> + if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO) >>>>>> + req->hdr.sync_hdr.Flags |= SMB2_FLAGS_SIGNED; >>>>>> rc = SendReceive2(xid, ses, iov, n_iov, &resp_buftype, flags, &rsp_iov); >>>>>> cifs_small_buf_release(req); >>>>>> >>>>>> >>>>>> >>>>> >>>>> This one needs to be backported to all stable kernels as the commit that >>>>> introduced the regression: >>>>> ' >>>>> 0603c96f3af50e2f9299fa410c224ab1d465e0f9 >>>>> SMB: Validate negotiate (to protect against downgrade) even if signing off >>>>> >>>>> is backported in stable trees as of: 4.9.53, 4.4.90, 3.18.73 >>>> >>>> Oh wait, it breaks the builds on older kernels, that's why I didn't >>>> apply it :) >>>> >>>> Can you provide me with a working backport? >>>> >>> >>> Hi Steve, >>> >>> Is there a version of this fix available for stable kernels? >>> >> >> Hi Greg, >> >> Mounting SMB3 shares continues to fail for me on 4.4.118 and 4.9.84 >> due to the issues that I have described in detail on this mail thread. >> >> Since there is no apparent fix for this bug on stable kernels, could >> you please consider reverting the original commit that caused this >> regression? >> >> That commit was intended to enhance security, which is probably why it >> was backported to stable kernels in the first place; but instead it >> ends up breaking basic functionality itself (mounting). So in the >> absence of a proper fix, I don't see much of an option but to revert >> that commit. >> >> So, please consider reverting the following: >> >> commit 02ef29f9cbb616bf419 "SMB: Validate negotiate (to protect >> against downgrade) even if signing off" on 4.4.118 >> >> commit 0e1b85a41a25ac888fb "SMB: Validate negotiate (to protect >> against downgrade) even if signing off" on 4.9.84 >> >> They correspond to commit 0603c96f3af50e2f9299fa410c224ab1d465e0f9 >> upstream. Both these patches should revert cleanly. > > Do you still have this same problem on 4.14 and 4.15? If so, the issue > needs to get fixed there, not papered-over by reverting these old > changes, as you will hit the issue again in the future when you update > to a newer kernel version. > 4.14 and 4.15 work great! (I had mentioned this is in my original bug report but forgot to summarize it here, sorry). Thank you! Regards, Srivatsa